University of Vermont Extension
Department of Plant and Soil Science
TAKING CUTTINGS AND
OTHER AUGUST GARDENING TIPS
Charlie Nardozzi, Senior
Dr. Leonard Perry, Extension
University of Vermont
Taking cuttings of azaleas and
favorite annual flowers, harvesting onions, and sowing cover crops are some of
the gardening tips for this month.
To propagate your favorite azaleas, take six-inch
long cuttings from new growth, strip off the lower leaves and remove any flower
buds, dip the cuttings in rooting hormone, then stick the cuttings in moist
seed-starting mix. Make sure the leaves don’t touch the mix. Cover the pot with
a plastic bag to hold in humidity, and set the pot in a cool, shady, protected
location outside. When cuttings have rooted (in about eight weeks) remove the
plastic covering by rolling it back a little more each day, and transplant the
cuttings into a protected location or in a cold frame to overwinter. Be sure to mulch well.
cuttings of favorite geraniums, coleus, begonias, and any other annual flowers
that you want to grow again next summer.
Also, you can bring these plants indoors for the winter if you have a
sunny spot. Several popular bedding
plants are perennial in warm climates and can be brought indoors as houseplants
if you don't wait until the weather gets too cool, which can set them back and
make it hard for them to recover. Gradually move the plants into shadier
locations so they are better adjusted to the reduced light levels when you move
Begin harvesting onions when
about half to three quarters of the leaves have died back. Gently dig or pull the onions and store them in a dry,
shady place with good ventilation, such as an outdoor shed or barn, for 10 days
to two weeks. After the onions have cured, separate the young, soft, and
thick-necked bulbs and use them first because they won't store well. Put the rest in slatted crates or mesh bags,
and store them indoors in a basement with low humidity and temperatures between
33 and 45 degrees F.
It’s time to start some mesclun greens and leaf
lettuce in bare spots in the garden for fall picking. Mix in some compost
before seeding and give new seedlings a dose of liquid fish emulsion.
Build the nutrient levels and
organic matter in garden beds by sowing cover crops like annual ryegrass or
buckwheat into empty annual beds. They will grow until winter kills them and
then can be incorporated into the soil in spring. Cut down buckwheat before it
flowers so seeds don't become a problem.
Late summer is a good time to
divide German and Siberian iris, rudbeckia, echinacea, daylilies, and tall
phlox. If plants are blooming well, with
strong stems, and you still have space for them, they shouldn’t need
division. Don't make the divisions too
small or you'll wait longer for blooms. Wait until after bloom to divide. Trim the foliage by at least half before
Be sure to set bearded iris rhizomes (the thick
roots) just barely below the soil surface to prevent rotting. When dividing these iris, check the rhizomes
for mushy areas with borers. Discard
affected roots, making sure to kill the borers.
Return to Perry's Perennial