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Annuals: A-D | F-N | P-Z
Quiz 5

Lecture 21a: Annuals: A-D (audio)

In these lectures on specific plants, I'll only mention the key points for each, leaving the remainder of the almost 400 pages and thousands of cultivars for your reference. As mentioned earlier in lectures, most flowers are fairly adaptable tolerating a range of growing conditions, and unless noted these conditions apply. this includes well-drained soil and sun. Each name is hotlinked to the notes on each plant. You may want to either listen to these summary notes below while you look at each plant page, or print this page out, noting the points on each plant page.  Since these plants are off this secure site, use your browser's back button to return to this page.

Most the plants we'll cover will be listed alphabetically by scientific name. Exceptions are the annuals, herbs and bulbs, which are most commonly known by the common names. If noted as an All America winner, this refers to the program of the All America Selections which each year chooses winners among the new introductions of flowers and vegetables. Normally the flowers are annuals, as they must bloom from seed the first year, yet if a perennial does it can be considered as well. In addition to being seed grown, flowers must be an improvement over existing cultivars in at least some trait. Winners are chosen in about 30 trial sites in North America, then flowers displayed at over 200 sanctioned gardens the year before release. A similar program exists in Europe called Fleuroselect.
 
 

Ageratum

The scientific name is also Ageratum, although it might also be seen as Mexican ageratum or flossflower. In the aster family (asteraceae), it is low (6 inches or so), so usually used in fronts of borders. Usually blue to purple, there are white and reddish cultivars although these tend to be less vigorous, especially the white. There is only one species of importance, houstonianum, with a couple key cultivars being 'Blue Horizon' and the Hawaii series.

Alyssum

Sweet alyssum (Lobularia) is another low annual for the front of borders. Flowers are characteristic of the mustard family (Brassicaceae), are usually white (pink and purple are less common), and quite aromatic. It is a smell most like or hate (I being of the latter), so smell it before planting it! It does not tolerate wet soil and very damp weather, rotting. In addition to fronts of borders, it can be massed in beds, used in rock gardens since it tends to spread a bit, or in containers for fine texture having small leaves and flowers. The only important species to us is maritima, a main white cultivar 'Carpet of Snow', 'Oriental Night' being dark purple, and 'Rosie O'Day' being lavender-rose.

Begonia

Here we're referring only to the wax-leaf begonia, Begonia semperflorens-cultorum, the Begonia family (Begoniaceae) being one of the largest, with other members under bulbs and tropicals. Generally only about 6 inches high, it too is for fronts of borders, massed or in containers as it forms a clump. It generally prefers shade, but tolerates sun quite well in the north if given adequate moisture. Having some of the smallest seeds of herbaceous plants (over a million per ounce), it must be sown with care, and 4 to 6 months before planting out. Probably the most popular are the Cocktail hybrids, with names such as 'Gin' and 'Vodka'.

Blanket flower

Gaillardia might also be known as Indian Blanket, as it has vivid bright yellow, or red, or mixed color flowers. It has a composite flower fairly characteristic of the daisy or aster family (Astraceae). The two main species, with differences as noted in flower and leaf size basically, are x grandiflora and pulchella. The main cultivar of the former is probably 'Kobold', also commonly seen as 'Goblin'. The main ones for the latter species, which tolerates dry and windy conditions, are 'Red Plume' (an All American winner) and 'Yellow Plume'.

Celosia

This is also the scientific name, and commonly is also known as cockscomb, a member of the Amaranth family (Amaranthaceae). Depending on cultivar, it can be 6 to 24 inches high. Foliage is usually green, but can be dark red and so used quite effectively in designs. Flowers can be a plumed spike, the plumed cockscomb, or a rounded mound, the crested cockscomb. Both have various bright, warm colors. In addition there are a couple other groupings based on flower types. This is one flower that the closer it is planted, the taller it will get. It is good along fronts of borders, massed, in containers or the taller ones as cut flowers. There have been several All America winners including 'Apricot Brandy' with green leaves, orange plumed flowers; 'New Look' with red flowers, red foliage and branched; and 'Prestige Scarlet' with red flowers and green foliage.

Chrysanthemum

As we mentioned under plant names, this is probably the best example of botanists changing names. The genus was the same, then became Dendranthema for this, the garden chrysanthemum, and now is being changed back. Here we'll be discussing only the garden mum (x morifolium), not the florist's mum or other relatives of the aster family (Asteraceae). We're considering it an annual since this course is based in a northern climate, but depending on the cultivar, can be hardy and so perennial in zones 5 and south. Even there though, it is often grown as a seasonal annual for fall.

It forms a mound, roughly a foot to two high and across, and the composite flowers come in many colors, especially the warm colors of fall. Depending on the flower shape, there are four main classes for the garden mum. Flowering with the shorter daylengths of fall, these can also be classified depending on number of weeks until bloom. There are literally hundreds of cultivars, new ones introduced and older ones retired each year. Popular new series include the Prophet series from Yoder, and the Belgians with smaller daisy type flowers and more of them.

Coleus

Originally known as Coleus blumei, botanists then made it much harder on students by changing the name to Solenostemon x hybridus. It has the characteristic 4-sided stems of the mint family (Lamiaceae). It is grown primarily for its foliage, coming in all colors and combinations, and with well over a hundred cultivars available. Formerly a shade plant, in recent years many of the cultivars tolerate sun quite well if sufficient moisture, and in fact have brighter colors in sun. I've seen these growing quite well in the full sun and heat and humidity of the Missouri Botanic Garden in St. Louis. They remain though one of the few annuals that will grow also in shade. They root quite easily from cuttings, so lend themselves to overwintering as rooted cuttings and small plants indoors. Here though they are quite susceptible to pests, particularly mealybugs. Some of the key series (several cultivars in each, usually from seed) are listed in the notes, as are examples of the cutting-propagated cultivars.

Cosmos

With genus name the same, the two main species are bipinnatus and sulphureus. The former is 5 to 6 feet tall, open habit with red, white, pink or lavender flowers 2 to 3 inches across. The latter species is more compact, 1 to 2 feet tall, generally orange or yellow flowers about 1 inch across. Flowers are composites, being in the aster family (Asteraceae). Bipinnatus is useful for fine texture, backs of borders, or cutting. A couple popular choices are the Sonata hybrids 2 to 3 feet tall, the Sensation hybrids 3 to 4 feet tall, or the unusual 'Sea Shells' with fluted petals. Sulphureus is best in fronts of borders or massed, and can self-sow especially in warmer climates. The Sunny hybrids may be the most popular, 'Sunny Red' being an All America winner.

Dianthus

With genus name the same, this may also commonly be known as China or annual or rainbow pinks. Pinks comes not from the color, being in reds, whites and purples too, but from the resemblance of the cut petal margins to the effect from "pinking" scissors or shears. It is in the pinks family (Caryophyllaceae). A low plant generally, from one to two feet, depending on cultivar, it is best used in fronts of borders, massed, in containers, or the taller cultivars as cut flowers. The species we're discussing here is chinensis, although barbatus --the Sweet William-- is often a short-lived perennial and so might be mentioned here and grown here as an annual as well. There have been several All America and Fleuroslect winners of chinensis, particularly the lower ones such as 'Ideal Violet'. Some flowers have combinations of colors, such as red and white, or perhaps Picotee or fringed edges as in the Parfait hybrids.

Dusty Miller

Listed now as Senecio, it might still be found listed as Cineraria being a group in the aster family (Asteraceae) with lots of names changes in recent decades. It's main attraction are the quite hairy and silvery-white leaves (turning greenish when wet), often with no flowers even seen. As such it combines and contrasts well with many colors, so is often used in designs, growing about 8 to 15 inches high and across. One cultivar with very finely cut foliage, 'Silver Lace' is actually a different genus--Tanacetum vulgare. The most commonly seen cultivar may be 'Silver Dust'.
 
 

Annuals: A-D | F-N | P-Z
Quiz 5


©Authored by Dr. Leonard Perry, Professor, University of Vermont.