As we close in on the fall equinox, it looks like the hot summer of 2024 might be waning. But I would not bet the farm on warm temperatures going away entirely. September and October have yin and yang weather. One day it might be in the 80s; the next day snow.
Since you’re already outside harvesting fruits, vegetables and herbs, might as well add these fall garden chores to the daily garden fun.
Bulbs: The two most common and must-do fall errands are to shop for spring bulbs and plant before the Halloween decorations go up; otherwise they’ll dry out and shrivel like the scary witch display. The best bulb quality and selection is on store shelves is now; if you wait too long, whatever is left unsold generally goes on sale. Promise yourself to plant the bargain bulbs before mashing the potatoes on Thanksgiving Day.
Perennials: Next, while you’re shopping for bulbs check out the sales aisle and pick up bargain perennials, trees and shrubs.
New fall plants appreciate the long cooler weeks to put down roots so that next year they are ready to take off and do their thing. Sale plants might be rootbound in the container, so be sure to “tease” or rough up the roots. In some cases, you may need to use sharp scissors or a knife and make cuts through circling roots. This method, along with teasing and roughing up, helps the plant grow new roots into the surrounding soil.
New evergreen trees and shrubs planted in the fall will need your utmost care and attention over the winter since they continue to transpire. That is, move water through their green needles (leaves), (Rread more on winter watering below.)
Divide: Next up is plant dividing, so next year they’ll have a huge head start. The plants will look like they belonged in their new location all along.
Some of the best plants to fall divide include spring and early summer blooming perennials like peony, columbine, salvia, catmint, daylilies, daisies, coreopsis and bee balm. Wait until spring to divide and replant late-summer perennials and fall bloomers like asters, mums, bachelor’s button, goldenrod, and more.
Water established plants a day or two before dividing or moving so the roots stay together better for the move.
Peonies can grow in the same location for many years if they are happy with the location, sun and are not overly crowded. Fall dividing or moving peonies is sometimes necessary. This is not difficult to do. However, there are some important tips to follow.
First, cut off the top green growth to near ground level. If the entire peony plant is dug up and moved, try to get all the roots and replant them at the same depth in its new location.
BULLET When dividing, look at the crown of the plant and notice the pinkish buds (or eyes). Use a knife to divide the plant so there are at least three buds or more in each division that will be replanted.
BULLET Plant divided peonies close to the surface, only 1 to 1 1/2 inches deep, and cover the buds with 1 inch of soil. Be sure to water well and mulch after transplanting. Remember that peonies bloom best in sunny locations, and transplants may take a season or two to rebloom.
Annuals: Why say goodbye forever to summer annuals in a few weeks? Take stem cuttings, also called slips, while plants are still growing for new plants next year. Cut healthy 6-inch or so growth from geranium plants, plucking the lowest leaves, and place in small containers with fresh potting soil. Using a rooting hormone (sold in garden centers) on the section planted in soil is helpful but not required. Place the cuttings in bright light and keep plants moist. Also take cuttings from coleus, fibrous begonias, sweet potato vine and place in water until rooted, then pot up into containers with potting soil and grow as houseplants near a sunny window or under indoor lights.
Watering: One fall and winter task that is often overlooked is the need for landscape plant fall and winter watering when natural moisture is not around or lacking, as is often the case in Colorado. Just because the calendar may say it is fall or winter does not mean that plants cease needing our watering attention once the sprinkler system is turned off or hoses are stored. Simply said: Plant roots that dry out will eventually die out.
The most important plants to continue watering all fall and through the winter into spring are the newest plants that went in this immediate past spring, summer and now, fall. This is across all categories — trees, shrubs and perennials — and includes plants that are water-wise so will need less water once their roots are established.
Keep records and create reminders if needed to check on these newer plantings and keep them moist, not sopping wet. A good 2 to 3 inch layer of mulch is helpful to keep them moist and can help prevent plants from the back and forth of freezing and thawing when temperature swings occur.
Landscape trees, new and mature, are our most valuable landscape assets. They are continuously being stressed, and often look it every summer into fall from lack of natural moisture and purposeful watering. Evidence of environmental stress like scorched leaves, early leaf drop and early color changes on lindens, maples and other trees are hard to ignore. These manifested stressors often are accompanied by pest or disease issues. If stressed trees could talk to us, they would say, “Hey, I need help, too. I’m parched and mostly ignored.”
Check to see that trees are getting moisture down in the root zone to a depth of one foot. Avoid overwatering all at once to compensate for lack of summer and previous year-round watering.
Mature tree roots extend far beyond the drip line through the landscape and into lawns and borders so keep in mind that if nearby landscape changes have been made such as removing or replacing turf, water needs for trees have not changed.
The bottom line is no one has a crystal ball to know the amount of rain or snow we’ll receive the rest of this year and next year. The best we can do is give our plants the care they require all year long.
Betty Cahill is a freelance writer who specializes in gardening in the Rocky Mountain Region.
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