There are some great events and programs on tap for this winter. The first one is a presentation on "Rhododendrons and Azaleas of Vermont" by Hal and Charlotte Bill on January 15. On February 13, "Exercises in Color for Gardeners" will be presented by Tom Vieth, international artist and FHF Board Member. Both events will be held at the Blasberg Building at the Hort. Farm starting at 7 p.m. See pages 3 and 5 for more details.
Then comes Vermont's largest horticultural event of the year, The Vermont Flower Show. This year's theme is "Over the River and Through the Woods." Sponsored by the Vermont Association of Professional Horticulturists in cooperation with the Vermont Department of Agriculture and UVM Extension, it will be held at the Sheraton in South Burlington from Friday, February 28 through Sunday, March 2. There will be educational seminars, flower displays, professional floral competitions, children's activities, and many, many exhibitors, including The Friends. Be sure to visit our booth and learn about all of our great projects and programs for 2003! For volunteer opportunities, see page 9 .
Also in March, The Friends will be sponsoring a two-day bus trip to the University of Connecticut. The focus of the meeting is "Theme Perennial Gardens." Registration and tuition for this event is due by March 5. March continues to be a busy month with The Waterbury Rotary Club Home and Garden Show on March 22-23. The Friends will have a booth there, as well. Finally, on Saturday, March 29, The Friends will hold its annual Crabapple and Lilac Pruning Work Day at The Farm.
Looking ahead to April, The Friends and The Vermont Chapter of The New England Wildflower Society for the seventh year in a row will co-sponsor a statewide event. The Gardening in Northern New England Symposium on Saturday, April 12 at Vermont Technical College. See page 4 for more details .
As I look ahead to the rest of the winter, I once again would like to extend the invitation to all members to volunteer to help at various events including set-up and cleanup, help at our lectures/workshops, and help with our collections and trails. Please contact our Volunteer Coordinator , Stephanie Miner at 863-1876 to express your interest. More than ever, we need the help of all members to fulfill our mission.
Sincerely,
John Hoogenboom, President
We hope you are enjoying your 2003 Calendar. Please take the time to answer the following questions so we can improve this product for next year:
Regional and national experts will address various aspects of "Theme Gardens" at this excellent and ongoing shortcourse for Master Gardeners and other gardening enthusiasts of all levels. Speakers will include nationally-known authors Colston Burrell, Tovah Martin, William Cullina, and international perennials consultant Robert Hermann among others. Special emphasis will be placed on ecologically sound gardening and garden practices, including plant choices. More details for this program can be found at: www.hort.uconn.edu/garden
This tour will cost $169 per person (double occupancy) and will leave the Burlington area at noon on Tuesday, March 18, with pick-up points in Montpelier, Hartland, and Brattleboro on the way to Storrs, Connecticut. Details regarding these arrangements and times will be provided in the confirmation of your registration. Overnight lodging, included in the tour cost, will be at the nearby Sleep Inn with an option for dinner on your own that first evening in the Sturbridge area nearby. After a complimentary continental breakfast, the following day will be spent at the meeting, returning afterwards, with an arrival time of approximately 11 p.m. in Burlington. A stop for a quick meal on your own will be made along the way. In the luxury coach several videos will be shown on gardening and English gardens, and refreshments will be provided.
To obtain a registration form and more information about the course, the single supplement option, and travel arrangements, see http://pss.uvm.edu/ppp/ctper03ad.htm or contact David Heleba at 656-0473, david.heleba@uvm.edu , or Dept Plant and Soil Science, 105 Carrigan Drive, Burlington VT 05405-0082 before March 5.
This tour may also be taken for one credit. See http://pss.uvm.edu/ppp/pss196theme.htm for more details.
I'm sometimes asked whether tree wounds should be treated. Some products sold in catalogs and garden stores claim to stimulate tree wound healing or wound closure.
An e-mail from David Lonsdale, a London tree pathologist who has done a lot of work on tree wound treatments, offers some useful observations. The term “healing” is the repair of damaged cells and does not usually occur with tree wounds. The exposed tissues from tree damage or limb removal usually die. Therefore, it is unlikely that dressings can “heal” a wound.
Closure of tree wounds occurs when the surrounding tissue grows to cover the wound. Studies have shown that certain products may encourage more rapid closure due to retention of moisture in the wound area or growth stimulation of surrounding tissues. However, it isn't always worthwhile, or even beneficial, to accelerate wound closure. Rapid closure can lead to an infolding of new tissues, which can result in cracking later in the trees life. Small wounds may close in a year or two without treatment while large wounds may fail to close during the trees lifetime, even if treated.
Lonsdale says the most aggressive xylem-inhabiting pathogens seem to need fresh wounds for their entry (no more than a month for some organisms). Enhanced closure of the wound will not be of any value against such pathogens, but protection of the wound surface can be useful in excluding them. On the other hand, retention of moisture by a wound sealant could keep conditions more suitable for infection. A lot depends on the weather at the time, as the pathogen has an optimal moisture range for infection. Either wetness or dryness can be inhibitory. Research on fruit trees shows that these fresh wound parasites are best controlled if the wound sealant contains a fungicide. Lonsdale observes that some biocontrol agents such as Trichoderma species can be effective against the fresh wound parasites.
So the question remains as to whether one should treat tree wounds. I think it usually isn't worthwhile because sealing in the moisture is as likely to cause trouble as not treating. Perhaps the best reason to treat is aesthetic, to cover prominent wounds with dark-colored dressings so they aren't so noticeable. However, don't use products such as paints or asphaltic roofing compounds not labeled for tree wound treatment. They may be toxic to living plant tissues.
“Rhododendrons and Azaleas of Vermont,” a slide show and talk, will be given by Hal and Charlotte Bill on January 15 from 7 p.m. to 9 p.m. at the Hort. Farm. Also presenting will be Adam Wheeler, a graduate student, who will show slides and discuss his project of propagating rhododendrons and azaleas that have a historical place in Vermont.
Vermont is close to the end of the world when it comes to native rhododendrons growing here, but we do have three native species. Small populations of R. maximum and R. prinophyllum are found in the state. R. canadense is much more prolific and can be found in abundance in areas of northeastern Vermont. We will show slides of these natives as well as slides of other horticulturally established rhododendron species, named cultivars, and hybrids of unknown origin, many of which have been growing here for 50 to 100 years. These plants have borne the test of time in an area not often considered hospitable to this genus.
There will be time for questions and discussion during this presentation, which will provide an excellent opportunity to learn more about these special plants.
Saturday, April 12, 2003 , is the date of the annual symposium, Gardening in Northern New England, to be held at Vermont Technical College in Randolph, Vermont, just off Interstate 89 at Exit 4. Registration begins at 9:00 a.m. and the program should end by 3:00 p.m. This is the seventh year that The Friends has co-sponsored this statewide symposium with the organizer, The Vermont Chapter of The New England Wild Flower Society.
About the Speakers:
Gordon Hayward, a certified member of the Association of Professional Landscape Designers, has restored, designed and developed gardens in England and throughout the Northeast of this country. His articles on this subject have appeared in Horticulture Magazine , Fine Gardening , Yankee Magazine, American Horticulturist and others. His books including Designing Your Own Landscape, Garden Paths and Stone in the Garden. His new book, Your House, Your Garden will be published in Spring 2003.
Jeff Good has been Landscape Manager at The Fells, a horticultural, educational and historic site in Newbury, NH, since 1999. Prior to that, he was sales manager for ten years at Millican Nurseries, a large wholesale operation in Chichester, NH. After attending UNH's Thompson School of Applied Science from 1979-81, he worked in commercial landscaping and estate management for Erin Food Services, maintaining 30 restaurants, and caring for estates on Nantucket, Beacon Hill, Lake Winnipesaukee, and in Bedford, NH.
William Cullina, nursery manager and propagator at the Garden in the Woods since 1995, has worked in plant propagation and nursery production for 18 years. He lectures on native plants and propagation to garden and professional groups and writes for popular and technical journals. His first book, NEWFS Guide to Growing and Propagating Wildflowers, was followed in 2002 by Native Trees, Shrubs and Vines, a guide to using, growing and propagating North American woody plants. His current project, a book on home orchid growing, is due in 2004.
About the Presentations:
The Uses of Stone in the Garden
- Gordon Hayward
Whether as walls, terraces, walkways, bold standing stones,
or boulders edging a stream, stone lends a garden focus, providing
a perfect foil to plants. The aesthetics and the practical concerns of
the proper way to lay and set stone underfoot, in walls, as garden ornaments,
and interacting with water will be addressed.
Alpines and Rock Garden Plants
for Northern Gardens - Jeff Good
Low-growing mounds and mats of sunny alpine areas, plants
of stream-side or scree, shade-loving woodland gems and dwarf evergreens
are the treasures rock gardeners cherish. Jeff will tell us which plants
do well in our climate, what to choose to have a full season of bloom,
and how to grow these plants.
Leaf, Bark, Flower and Fruit:
Small Native Trees, Shrubs, and a Few Vines - Bill Cullina
Native trees , shrubs and vines are not only beautiful and
versatile, they are the cornerstone of local ecosystems. In this presentation,
Bill Cullina will profile some of the fabulous natives appropriate
for smaller spaces, with an emphasis on species that are easy to grow
and that provide interest throughout the season.
About the Organizer
:
The New England Wild Flower Society, the oldest plant conservation
organization in the U.S., promotes the conservation of temperate North
American plants through education, horticulture, research, habitat preservation
and conservation advocacy. The Society's botanical garden, Garden in
the Woods, displays the largest landscaped collection of wildflowers in
the Northeast. Each year, the Society offers programs throughout New England,
reaching over 50,000 participants.
A portion of the New England Wild Flower Society's general
operating funds for this fiscal year have been provided through grants
from the Institute of Museum Services, a federal agency.
Registration Fee:
$50, non-members; $42 for members of NEWFS, The Friends of the Horticulture Farm, The Hardy Plant Club, and The Fells. Includes symposium packet, lunch and free parking. Map and directions will be sent to registrants.
Registration Deadline:
No cancellations will be accepted
after April 1
.
Gardening in Northern
New England
Saturday, April 12, 2003 9:00 a.m. - 3:00 p.m.
(Please PRINT clearly)
Name: _________________________________
Address: _______________________________
City: __________________________________
State: ________ Zip Code: _____________
Daytime Phone: _____________
Evening Phone: _____________
Check if you are a member
of NEWFS___, The Friends of the Horticulture Farm___
*, The Fells___, or Hardy Plant Club___.
Total amount enclosed: $_________
Make checks payable to NEWFS VT (preferable)
or Credit Card no. _____________________
Exp. Date: _______ Signature:________________
For additional Registrants: Please attach a photocopy of this form on a separate sheet.
Mail to:* If you are unsure when your FHF membership expires, look at your mailing label on the front of this newsletter. The date above your name is when your membership is due. If your membership has lapsed or will do so shortly and you renew today, we can confirm your renewal with NEWFS-VT.
All activities are to be held at the UVM Horticultural Research Center in South Burlington, unless otherwise specified. Call the office of The Friends of the Horticulture Farm for details. We request phone reservations to help us with event planning. Call: 864-3073, unless otherwise indicated.
January 15
Rhododendrons and Azaleas of Vermont
7 - 9 p.m.
Presenters: Hal and Charlotte Bill, ADP Nursery
Expand your knowledge through a slide presentation and talk by Charlotte
and Hal Bill. Hal will discuss basic conditions for success with growing
these plants. A slide presentation highlight significant specimens
grown in different Vermont climates. See page 3 for more details.
January 18
Collections & Facilities Committee meeting
9 a.m. - 1 p.m.
Come to this important meeting of the Collections & Facilities
Committee to learn what projects will be happening during the non-gardening
season. Proposed agenda items include: plans for the "Invasive Plant
Workshop" in April, ideas for a Wetland Garden, a possible field trip
to local natural areas. New members welcome! Contact: Hal Bill at
933-2004, rhodotree@hotmail.com
or BJ Allen at 879-6743, bjallen@gmavt.net
.
February 13
Exercises in Color for Gardeners
6 - 9 p.m.
Presenter: Tom Vieth, Artist and Gardener
Hands-on workshop using cut up magazine images to explore color
relationships to link color theory from two dimensional art to uses
in the garden according to personal style preferences. Bring gardening
magazines, scissors, and glue.
February 28, March 1 &
March 2
Vermont Flower Show
9 a.m. - 6 p.m.
Sheraton Conference Center, Burlington.
"Over the River and Through the Woods" is the theme for Vermont's
premier and largest horticultural event of the year. There are three
days of concurrent educational seminars, flower displays with model train
layout, professional floral competitions, children's activities, and
many exhibitors. Sponsored by the Vermont Association of Professional
Horticulturists in cooperation with the Vermont Department of Agriculture
and UVM Extension. Come visit The Friends booth and learn about our
great programs and projects in 2003!
March 13
The Friends of the Horticulture Farm Board of Directors meeting
3 - 5 p.m.
Members are always welcome to attend and share their ideas with
the Board.
March 18 & 19
Perennial Gardens Bus Tour to UCONN at Storrs
Leader: Dr. Leonard Perry, UVM Extension Horticulturalist
Lodging, bus, registration and lunch included. The focus of the
meeting is,"Theme Perennial Gardens". UVM credit available, by special
arrangement. Reservations due by March 5. See page 2 for more detail
for registration information.
Another Interesting Event...
January 28-30
The Vermont Farm Show
Barre Civic Center, Barre, VT
Agricultural displays, farm product contest, annual meeting of
commodity groups, farm machinery, commercial farm exhibits. Vermont's
premier winter show. Contact: Jon Turmel, Manager, VT Dept of Agriculture,
(802) 828-3490, e-mail: jon@agr.state.vt.us,
website: www.uvm.edu/extension/farmshow/
Stream Buffers
by Jim Pease of the Water Quality
Division,
Department of Environmental Conservation, Vermont Agency of Natural
Resources
What are stream (riparian) buffers? Why are they important? What do buffers actually do?
Stream buffers are lands adjacent to perennial surface waters including both the main channel and the smaller tributaries. The lands are protected from disturbance or encroachment by law (state or municipal) or voluntarily through landowner agreements. The goal in creating buffer lands is to reestablish a mature riparian forest along side the stream or river. Buffers vary in width but typically a 25-100 foot vegetated buffer on each side of the stream is adequate. If undisturbed, the buffer can provide the essential functions of sediment trapping, streambank stabilization and consequently stream channel stability, and wildlife habitat. It is these primary functions that make buffers a valuable and important means of preventing nonpoint source pollution (NPS). NPS pollution is pollution from land use activity versus pollution from the end of a pipe.
Vegetated buffers can filter stormwater runoff from residential lawns and impervious surfaces, cornfields and pastures, and logging jobs and logging roads. The buffer can trap sediment, nutrients and other pollutants in runoff if the water sheet flows into it from the adjacent lands. If water is piped or concentrated as it flows overland the effectiveness of the buffer to trap the runoff is greatly reduced.
Tree and shrub roots along stream banks hold soil in place and resist the water's erosive energy during flood events and spring runoff. Trees and shrubs provide niches for insects and water fowl; insects are food for fish and fish are food for some species of birds. These plants provide litter and leaf drop that creates instream habitat such as pools for fish formed by log dams and leaf packs in the fall, which feed aquatic insects.
No less important are the secondary benefits of buffers such as locations for recreation paths; wildlife corridors for mammals such as beaver, otter, weasel and muskrat; and protection for cultural and Native American sites such as campsites, mill sites and homesteads. In older and larger urban areas, such as Baltimore, Washington, DC, and even Burlington, buffers and recreation paths have been created in conjunction with the construction of sewer and storm sewer lines. The lines were designed to take advantage of gravity, allowing water to drain from the highest point in a watershed to the lowest. Paths were laid out on top of the lines providing maintenance access but also creating an extensive and popular network of foot/bike paths and interlinked open spaces.
Protecting the integrity of existing buffers, and expanding them where none exist, is one of the most cost effective NPS water pollution prevention techniques available. Many of the sources of sediment in our streams and rivers come from eroding and collapsed banks that are the result of overzealous land clearing such as farms expanding crop lands, residential homeowners increasing the size of their lawns, and logging jobs maximizing their harvest. It is often difficult for landowners to see the connection between dynamic stream channels, root structure and streambank stability, but the lack of watershed vegetation buffers is often the principal reason for property loss and unstable streamside slopes during flood events. In place of buffers landowners often resort to retaining walls, riprap or other much more expensive techniques to stabilize their streambanks. While these techniques are useful where there is an immediate threat to property or infrastructure, their widespread use is not necessary and sometimes counterproductive, actually contributing to further erosion problems.
What can you as a landowner do? On the farm, state law requires a 25-foot buffer between tilled land and all waterways. Leaving this buffer alone, permanently, and expanding it where possible, will have benefits for the environment and reduce farm soil loss. Large farm operations often prefer to harvest crops in straight lines rather than following a meandering river course so fence lines can be placed to take advantage of this practice. The US Dept. of Agriculture and the US Fish and Wildlife Service have a number of programs that provide financial incentives for creating riparian buffers.
Urban and suburban homeowners should check their local zoning rules to learn more about buffers. In Chittenden County, Colchester, Essex, Jericho, Shelburne, South Burlington, Westford and Williston have all created buffer zoning on their perennial waters. Loggers must, according to state law, keep roads and equipment outside of a 25-foot buffer strip along streams or water bodies and this buffer increases to 110-foot with increasing slope. Light thinning or selective harvesting is allowed within the buffer.
The Friends of the Horticulture Farm, the Burlington Garden Club and the Vermont Commons School recently published a brochure for landowners, entitled "Controlling Erosion in Your Backyard ," that has simple techniques on how to stop erosion and reestablish buffers where they have been removed. These practices have been installed on the UVM Horticulture Farm and at the UVM Dairy Farm. The Vermont Youth Conservation Corps installed these practices at both UVM facilities and is available to work on buffer projects on other large properties in Vermont.
Native willows such as black, balsam, sawtooth, long-beaked, bog, pussy, slender and silky can all be used to quickly reestablish stream and river buffers in Vermont. These species typically root easily and if broken or damaged reroot on their own. Red-osier and silky dogwood are also good riparian buffer species to use when reestablishing vegetation on streambanks. If there is no local source for cuttings available, several of these species can be purchased through your local USDA Natural Resource Conservation District or as part of a landowner agreement with the USFWS Partnerships in Wildlife program. Since the 1930's, the weaving of these plants into eroded stream and river banks using bioengineering techniques like wattles, live stakes, brush rolls and brush layering, has been successfully advanced as a cost effective means of erosion control which also preserves the primary functions of buffers.
For more information on buffers and how to create them on your land, contact The Friends of the Horticulture Farm or the Burlington Garden Club for a copy of the backyard erosion brochure. Also:
For more information about the Bartlett Brook Restoration Project and other watershed improvement initiatives in Chittenden County, contact Jim Pease, Water Quality Division, Stormwater Management Section, 10 North Building, 103 S. Main Street, Waterbury, VT USA 05671-0408, or phone him at (802) 241-2683, or e-mail him at JimP@dec.anr.state.vt.us
Corylus colurna
by Adam R. Wheeler, Graduate Student, Dept of Plant & Soil Science
The genus Corylus contains a group of trees and shrubs that are native to temperate regions of North America, Europe and Asia. These plants are enjoyed by wildlife and humans alike for their sweet nuts, which are high in protein and essential fats. Unfortunately, the ornamental value of the species contained within this genus is often overlooked.
One such example is Corylus colurna (Turkish filbert). This native of southeast Europe and western Asia has many ornamental qualities that justify a more prominent place in our landscape.
In its native range, this moderately fast growing tree can reach more than 60 feet in height. In cultivation, a height of 40-50 ft can be expected in as little as 30 years. Once established, this plant is tolerant of many adverse conditions and is recommended for use in formal landscapes, as a street tree, or specimen plant. It will thrive in full sun exposure and is hardy in USDA zones 4-7.
In the landscape, this tree will please year round with its distinctive pyramidal habit that brings a stately strength to any lawn or garden. In early spring a moderate display of catkins will emerge from winter's rest. These 2-3 inch long male inflorescences will put on a handsome brownish-yellow display. As summer arrives, dark green heavy-textured leaves cover the tree. These broadly ovate leaves are 2.5 to 6 inches long and are arranged alternately along the stem. The foliage is insect and disease free. It provides a great contrasting background to summer blooming shrubs. In winter, mature plants continue to impress with their gray-brown, flaky bark, that is reminiscent of the North American native, Ostrya virginiana (hophornbeam, ironwood).
The easiest method to propagate Corylus colurna is by seed. The seed has a very hard seed coat and requires some form of scarification. I have had good luck germinating small batches of seeds by nicking the seed coats with a file and then placing the seeds in cold moist stratification for a 6-month period. Unfortunately, seed is often difficult to come by as plants do not produce fruit until well into maturity. A 20-plus year old tree at the Hort. Farm has yet to yield a single nut.
Asexual propagation by cuttings is also possible but has been reported to be difficult and inconsistent. In my limited experience, I have had moderate success (60%) using greenwood to semi-hardwood cuttings collected in early August from a 20 year old plant. Cuttings were treated with 8,000 ppm K-IBA (editor's note: K-IBA stands for Potassium salt of Indole-3-Butyric Acid, a common rooting hormone used in plant propagation .) and stuck in a 1:1 perlite: vermiculite mix on bottom heat under intermittent mist. Using this method, rooting took place in 6-8 weeks.
Corylus colurna is an excellent ornamental tree that
is a valuable addition to any landscape. Its pyramidal habit, dark
green leaves, and attractive flaky bark at maturity make it an excellent
formal tree that should be added to everyone's plant pallet.
A Green Day for the Burlington Community Tree Nursery
by Margaret Skinner, Nursery Manager and Entomologist
Branch Out Burlington! got the best New Year's present they could have wished for this week. The National Tree Trust awarded them $7,500 to support their Burlington Community Tree Nursery. Branch Out Burlington! is a volunteer group working to plant and care for trees around the city's streets and parks.
Two years ago, on land contributed at the University of Vermont Horticultural Research Center, the group started a community nursery to provide a sustained source of low-cost trees for Burlington. With lots of help from volunteers, each year members plant 60-70 small saplings. After two to three years of tender loving care, the young trees are transplanted along the streets to fill the thousands of empty spaces waiting for them. "The nursery is great for the community," says Nancy Knox , President of the organization. "It gets people to take a personal interest in the trees around them, and we hope that will get them to take care of the trees when they leave the nursery."
The nursery will save the city thousands of dollars in the years ahead. It costs about $30 to grow a tree in the nursery. A tree of equal size from a commercial nursery can cost $200. Funds from the Burlington Community Block Grant Program and the VT Urban and Community Forestry Program helped get the nursery started. The nursery would not be possible without the help and advice of Dave Heleba, who installed drip irrigation for the trees this year. The Tree Trust award will enable Branch Out Burlington! to purchase additional supplies and the tools needed to arm the many volunteers it takes to plant and care for the trees throughout the year.
It isn't as simple as it looks to grow a tree in the nursery, though. Every year something goes wrong. The first year the hackberry saplings didn't leaf out for several weeks after planting, because they didn't break dormancy. Luckily hot dry weather early in the season snapped most of them out of it. This year the late frost killed the young leaves of the hackberries, though thankfully they releafed quickly. The heavy winds blew some of the trees over, so they had to be staked. The managers learn something new every year, and hope that in a few years they will be "experts."
Despite these few problems, the trees are looking great. There are 137 trees in the nursery now, and 70 more will be planted this spring. The first trees from the nursery will also be transplanted along Burlington's streets this year. The annual community tree planting day is set for Saturday, April 26, and planting of the trees in the nursery will be in early May. Anyone interested in helping in the nursery should contact Margaret Skinner , 656-5440, email: mskinner@zoo.uvm.edu.
Flower Show Volunteers!
Once again The Friends of the Horticulture Farm will have an informational display booth at The Vermont Flower Show. This annual, early spring show is sponsored by the Vermont Association of Professional Horticulturalists. The dates will be February 28 and March 1 from 9 a.m. until 6 p.m. and March 2 from 9 a.m. - 4 p.m. It will be held at the Sheraton Conference Center in South Burlington. In addition to the booth, The Friends will be sponsoring a lecture room on Saturday, March 1. The Friends is asking for volunteers to staff the booth or to serve as "moderators" for lectures in our room. If you're interested, please contact our Volunteer Coordinator, Stephanie Miner, at 863-1876 .
Strybing Arboretum and Botanical Gardens - San Francisco
by John Craighead
Visitors to San Francisco have much to choose from when planning a vacation or seeking diversion from business. No doubt gardeners will relish the pocket plantings that dress the downtown sidewalks and building alcoves. And some will find time to visit the elegant formal Fililo Gardens south of the city, or Muir Woods, an awe-inspiring stand of ancient coastal Redwood, to the north across the Golden Gate bridge. But when I have free time in the Bay area, I find my way to the Strybing Arboretum and Botanical Gardens in Golden Gate park, a short, but $15.00 taxi ride from downtown.
I have visited Strybing at various times of the year, but most recently I traveled there on a chilly afternoon during December. My concern that the garden might be dormant, and thus lacking in interest, was soon allayed for many plants were in bloom (despite the chill in the air) and a few displayed strikingly luxuriant inflorescences.
Protected and somewhat shaded by specimen trees native to the West Coast - the western Red Cedar, Sequoia, Sugar Pine and Douglas Fir - were plantings of flora from several southern hemisphere countries having Mediterranean climates similar to the central California coast. In the South African garden were representatives of the richly-flowered Cape Province. A diversity of Protea were in full bloom and a rich display of the rose-colored bulbous Nerine sarnaiensis took central stage. Several different Aloe and Crassala, unique to the dry hillsides of this region, seemed refreshed by the cool wet California air and a few hinted impending blooms.
Elsewhere, a collection of plants from Australia contributed to the gardens ambiance. These plants commonly exhibited the attenuated, prickly branches of dryland denizens. Flowers are personal favorites of mine, members of the genus Leptospermum with their terminal clusters of tiny pink - white blooms. Rarely seen in this country were representatives of the flora of coastal Chile with fine examples of vines with crimson bell-shaped flowers ( Campsidium valdivianum, Mitraria cocccinae ) climbing the trunks of Cedar. These colorful plants seem to thrive in California and are just as impressive here as in their native land.
Strybing displays a major commitment to the flora of the Mexican highlands with many brilliant yellow and showy white members of the Astracea family in full bloom. Several examples of Century Plant and a diversity of other Yucca added interest. One wonders just how tall their bloom-covered spikes will rise into the sky!
Strybing Garden also has a commitment to the flowers of the highlands of Yunnan province in southwest China and the nearby Himalayas. Familiar faces were evident; some well known to those who visit this remote "hot spot" of floral evolution, and others because they have adapted well to the gardens of North America. Perhaps best known of these are members of the vast Rhododendron family, examples of which are shown throughout the Garden.
Strybing Garden displays are far from static. Since my last visit three new gardens have been added: one, a Biblical Garden, comprised of plants mentioned in the Bible, or commonly found in the lands of the eastern Mediterranean; Second, a Fragrance Garden, emphasizing herbaceous plants with distinctive pungent odors; and finally, a Bog Garden with a self-guided tour through a sequence of plants, organized to show how they evolved over the eons of geologic time.
Strybing is a community garden located in a heavily-populated residential area of the City. Neighborhood visitors enjoy miles of trails that wind through forests, gardens and fields. Clearly, the gardens have a popular following among San Francisco's citizens. Yet, one rarely reads of the Strybing Garden in traditional tourist manuals. It is clearly one of the wonders of the Bay area, not to be missed.
The Effects of Freezing and Thawing Conditions on
Cold Hardiness of Containerized Herbaceous Perennials
by Cheryl Bruce, Graduate Student, Dept of Plant & Soil Science
For my graduate thesis project at UVM, I conducted four studies to compare the effects of various freezing methods on the hardiness of containerized herbaceous perennials. Containerized plants were subjected to controlled freezing for three to four weeks. Plant hardiness was evaluated based on a visual rating scale, number of flowering stems, shoot height and width and dry weight.
In the first study, length of the acclimation period at -2C and duration of freezing at subzero temperatures were examined. Dianthus deltoides 'Vampire' and Geranium x cantabrigiense 'Cambridge' were acclimated for 1, 2 or 7 days at -2C and then frozen for 30 minutes, 2 hours or 24 hours at one of four treatment temperatures (-5, -8, -11, -14C). A control group remained at 3C. Significantly, lower regrowth was observed on those plants subjected to 7 days of acclimation at -2C. Regrowth and survival was also significantly lower for those plants held at subzero treatment temperatures for 24 hours.
A second study compared the hardiness of established, one-year-old plants that had been used in previous freezing studies with new plants that had been transplanted from plugs ten weeks prior to freezing. Established and new plants of Tiarellacordifolia 'Brandywine', T. wherryi 'Martha Oliver' and Geranium x cantabrigiense 'St Ola' were acclimated for 2 days at -2C and then frozen for 2 hours at one of four treatment temperatures (-5, -8, -11, -14C). A control group remained at 3C. Both species of Tiarella displayed significantly more regrowth as new plants than as established plants. However, Geranium plants that had been established were more successful than those that were newly potted.
Thawing rates after periods of controlled freezing were examined in two separate studies. Rapid thawing is the transfer of plants from a subzero treatment temperature (-5, -8, -11, -14C) directly to 3C conditions. Slow thawing is the slow increase of the freezer temperature to the acclimation temperature of -2C at the controlled rate of 2C/h before transfer of plants to 3C conditions. In the first study, Geranium 'Cambridge' was acclimated for 2 days at -2C and then frozen for 24 hours at one of four treatment temperatures (-5, -8, -11, -14C). After freezing, plants were either transferred to 3C conditions or raised to -2C. Plants were held at -2C for an additional 24 hours before transfer to 3C conditions. Plants exposed to rapid thawing displayed higher rates of regrowth and survival than those subjected to slow thawing due to the prolonged freezing duration of slow thawing.
In the second thawing rate study, the process was repeated with Geranium 'St Ola' and 'Karmina' and Tiarella 'Brandywine' and 'Martha Oliver,' except that in the slow thawing treatment, plants were held at -2C for 2 hours rather than 24 hours. Tiarella exposed to rapid thawing experienced higher rates of regrowth and survival than those exposed to slow thawing, while the opposite was true for Geranium 'Karmina'. The difference may be explained by the hardiness of the genus, where prolonged exposure to subzero temperatures is not as damaging as for a genus such as Tiarella . G. 'St Ola' had minimal survival in both treatment groups.
The influence of temperature cycling prior to controlled freezing was studied on Dianthus 'Vampire' and Geranium 'Cambridge'. Temperatures cycled between either -3 and +3C or -8 and +8C and plants were held at each temperature for 24 or 72 hours as temperatures were lowered, raised and lowered again before freezing at treatment temperatures (-5, -8, -11, -14C). A total of six cycling processes were studied (-3/+3C 24h, -3/+3C 72h, -3C 24h, -8/+8C 24h, -8/+8C 72h, -8C 24h). The range of temperature fluctuation is the determining factor on plant hardiness. Plants that cycled between -3/+3C for 24 and 72h displayed significantly higher regrowth and survival than all other treatment groups. Plants that cycled between -8/+8C for either 24 or 72h exhibited significantly lower regrowth than all other groups.
To view my full thesis presentation, please visit: http://pss.uvm.edu/ppp/brucethesis/index.htm
Every year dozens of promising new flower varieties are trialed at test sites throughout the country, including the University of Vermont, as part of the quest to find varieties worthy of the All-America Selections (AAS) winner title. Independent judges select flower varieties that score highest for bloom time, pest and disease-resistance, fragrance, interesting form, and other unique characteristics.
This year ten flowers made the cut, including Ornamental Millet 'Purple Majesty,' which received the AAS Gold Medal. This top honor, awarded only rarely by the judges, recognizes breeding breakthroughs.
Other 2003 AAS flower winners include Agastache 'Golden Jubilee,' Carnation 'Can Can Scarlet,' Petunia 'Blue Wave,' Petunia 'Merlin Blue Morn,' and Rudbeckia Hirta 'Prairie Sun.' AAS bedding plant award winners are Dianthus 'Corona Cherry Magic,' Eustoma 'Forever White,' Gaillardia 'Sundance Bicolor,' and Vinca 'Jaio Dark Red.'
Ornamental Millet 'Purple Majesty,' so named for its attractive purple leaf blades and shiny purple spikes (when the seed matures), is the first ornamental millet to receive this award. While a striking addition to any garden, it also is a favorite food source for many birds. Plants reach heights of three to five feet with 10 to 12-inch long spikes in mid to late summer.
This variety, resembling the grass Pennisetum, needs the sun, both for healthy growth and to induce the leaves to develop their lovely purple color. Plant two feet apart, waiting until the soil is warm before planting in the spring. 'Purple Majesty' also works well as a container plant. During the drought this past year this plant held up quite well.
Agastache 'Golden Jubilee' is an aromatic herb with golden-hued foliage on top and lime green lower leaves. It earned the AAS distinction for being easy to grow--it thrives in full sun or partial shade, requires no pruning or pinching back, and is essentially pest-free. The serrated leaves give off a strong mint aroma when crushed and can be used for flavoring or tea.
The common name is anise hyssop. It can be grown in large patio or deck containers or in gardens, spaced eight to 12 inches apart. Plants grow 15 to 20 inches high with three-inch lavender-blue spikes that attract bees. 'Golden Jubilee' commemorates the 50-year reign of Queen Elizabeth II.
If you are looking for a fragrant flower for your garden, Carnation 'Can Can Scarlet' may be the answer. It makes an excellent cut flower with its brilliant scarlet, double, two-inch blossoms; gray-green foliage; and spicy scent. It's a prolific bloomer, even in a hot and humid summer. It prefers full sun and can be grown either as a container plant or in a flowerbed. Plant height is 14 to 16 inches. Space plants 10 to 12 inches apart. Because plants take 120 days to flower from seeds, in northern climates potted plants, which should be available at garden centers starting in Spring 2003, are your best bet.
Two petunias were named AAS winners this year. 'Petunia 'Blue Wave' is a cascading variety with velvety purple two-inch blooms that is ideal for hanging baskets or as a spreading ground cover, such as on a slope or hill. It is easy to grow, requiring no pinching or pruning, though it will benefit from application of a slow-release fertilizer at planting and mid-season to promote blooming. In gardens, space plants one to two feet apart.
In full sun, Petunia 'Merlin Blue Morn,' will bloom prolifically throughout the summer. It is being billed as a patriotic flower as its unique coloring--a solid white center with velvety blue around the edges--makes it the perfect addition to a bed or hanging basket of red flowers. Like 'Blue Wave' it is a cascading variety suitable for both beds and containers. Plants should be spaced about a foot apart.
Rudbeckia Hirta 'Prairie Sun' was selected as an AAS winner for its unique coloration--a light green center surrounded by golden petals tipped with primrose yellow. It is the only rudbeckia or black-eyed Susan with this combination of colors. Mature plants are about three feet high with five-inch blooms on strong branching stems. 'Prairie Sun' does best in full sun and although an annual, in warmer climates it may overwinter and bloom again the following year. It makes a good cut flower and will do well in containers. If planting in a flowerbed or garden, allow 15 to 20 inches between plants. Flowering occurs just over three months from seeding.
"Magic" aptly describes Dianthus 'Corona Cherry Magic,' one of the four bedding plants named 2003 AAS award winners because its blooms can be cherry red, lavender, or a mosaic of both colors. Like many of this year's winners, it requires little work to grow and is not fussy about growing conditions. It tolerates a range of temperatures though it does prefer full sun. Flowers are single, two to three-inch blooms. Plants are short, growing only seven to nine inches tall. 'Corona Cherry Magic' can be grown fairly close together and will begin flowering about 10 to 12 weeks after seeds are sown. It also makes an excellent window box or container plant.
Plant breeders created Eustoma 'Forever White,' the first white-flowering Eustoma for home gardens, from Eustoma grandiflorum, a native wildflower found in Colorado, Texas, and Nebraska. It likes full sun and will thrive on heat, so don't rush to get it in the ground in the spring. Wait until the soil has warmed before transplanting. It also adapts well to container planting. Flowers are ivory or white, cup-shaped, and about two and one-half inches in diameter. Plants grow a foot high and should be spaced from six to eight inches apart.
Gaillardia 'Sundance Bicolor,' which looks like a wildflower, is a good choice for a native plant garden. A sunny spot is best. Both heat and drought-tolerant, this variety needs little attention once established and does not need to be watered unless the summer is dry. It has a spreading, mound growth habit and a most unusual mahogany red and yellow bicolor flower. Blooms are double and globe-shaped. The foot-tall plants also are suitable for baskets and containers.
The final AAS winner is Vinca 'Jaio Dark Red.' Described by the judges as "the best red yet in vinca," it has rich crimson red, two and one-half inch blossoms with round petals and white centers. The foliage is glossy green. Expect blossoms in about 70 days. This vinca requires little water and prefers warm soil and growing conditions. Plant 12 to 15 inches apart when soil warms up in the spring in a location that gets full sun. Plants grow 15 inches high and may spread up to 15 to 20 inches wide. Unlike most other vincas, deer and insects are not attracted to this plant.
In addition to these ten flowers, two vegetables, Melon 'Angel' and Summer Squash 'Papaya Pear,' also were selected as 2003 AAS winners. To learn more about these varieties and past winners, or to view photos of the winners, log onto www.all-americaselections.org.