September horticultural hints
by Betty Sanders
Weed every chance you get. Every weed you remove in the Fall – so it doesn’t spread seeds – is a thousand weeds you won’t have to remove in the spring! Plant woody plants ASAP. If you find yourself with a new tree or shrub, get it in the ground as soon as possible. It will need to grow roots to withstand winter winds and to supply water to the plant until the ground freezes. Dig a hole wider than the root ball of the plant (to help the new roots), tease out any winding roots, and create a saucer around the stem to direct water into the root zone. Water until the ground freezes if the autumn rain is not generous. Evergreens, because they keep their foliage, are especially vulnerable in their first winter. Add six inches of mulch (for the first winter only, and keeping the mulch away from the plant’s stem) before the temperature drops, to keep the roots warmer a little longer so they can continue to grow and take up water. Dig up your gladioli, caladiums, cannas and tuberous begonias before the first frost. Dry them in a garage or airy garden shed, remove the excess dirt and browned shoots. Place them in mesh bags or in open boxes with identifying tags, and lightly cover then with Styrofoam ‘peanuts’ in a dry, cool (not freezing) location for the winter. Your last opportunity to do something about swallowwort. By early September, seed heads on black swallowwort – which is deadly to certain caterpillars – are turning brown. Once they ripen, seed pods will open and – like the milkweed to which it is related – the seeds will scatter on the wind. If you see swallowwort with seed heads, pull it, bag it, and send it to be incinerated (never composted). The butterflies will thank you. The simplest way to control powdery mildew is to spray it with a solution made from one tablespoon of baking soda in a gallon of warm water. It’s perfectly safe and harmless to you and your plants (after all, you put it in your cakes…). Phlox, peonies, lilacs, monarda and dogwood should be checked for infections.
Feed woody plants and your perennials with a layer of good compost (two to three inches) followed by a layer of chipped leaves, straw or wood chips. The material will be naturally incorporated into the soil by the freezing and thawing over the winter and be available to your plants in the spring. If you have not used herbicides on your lawn this year, leaves shredded by your mower, along with grass clippings, are excellent mulches. In the Vegetable Garden. It’s planting time again. If you put lettuce, arugula, spinach and even pea seeds in the bare areas of your garden at the beginning of September, you can have a fresh crop before the weather turns too cold. And you can stretch the season even further by using floating row covers—lightweight cloth—over the plants on cool nights. Tomatoes have taken over center stage now, and perhaps your kitchen counter. But they cannot tolerate cool temperatures so remove the topmost growth on plants to encourage ripening what is already on the vine, instead of producing more fruit that will not have time to ripen. For better results storing them, allow winter squash and pumpkins to thoroughly ripen before harvesting. And remember, once harvested, to keep them in a cool but not cold place. As each vegetable finishes producing, remove the plants from the garden in order to prevent diseases or pests from wintering over in the old foliage. Sowing winter (or ‘annual’) rye will provide roots to stop erosion of uncovered soil, and when turned over in the spring, it will add nutrients and biomass to the garden.
In the Flower Garden. Autumn is a great time to divide and plant many perennials. If your perennials have finished blooming, consider digging and dividing them. Everything from peonies to bleeding hearts can benefit by creating divisions of the ‘mother’ plant. As you plant, make certain to put divisions into ground at the proper depth—exactly as deep as they were growing before. And enrich the soil with compost or well-aged manure to give the roots a great start. Don’t allow the new plantings to dry out, and don’t mulch the area until cooler temperatures arrive.
Bachelor Buttons can be planted in the fall to get a jump on Spring. And you can plant seeds now! Some flowers (such as bachelor buttons) do better if they are planted in the fall (the way Mother Nature would) and allowed to winter over. In the spring you will have a serious jump on those only putting their seeds in the ground meaning stronger, earlier flowers next summer. September is the month to plant all narcissus (daffodils) as well as smaller bulbs. Don’t plant tulips until the end of the month. And remember, while deer and rabbits love tulips, they generally ignore daffodils and hyacinths. Preparing for the nibblers and gnawers. Deer, rabbits, and rodents damage your plants by feeding on foliage, twigs, and bark when their regular diet disappears in the winter months. Wrapping tree trunks is a way to keep your landscape safe from hungry critters. Place plastic tree guards around the bottom of your deciduous trees (especially young or newly planted ones) to keep rabbits and mice from gnawing. Chicken wire barriers or cages around your trees, shrubs, and plants are often the best solution to keep rabbits at bay. Applying repellent sprays to the trunks, branches, and stems of evergreen trees and shrubs is a great option. Repellent sprays will need to be re-applied monthly but teach critters to look elsewhere year round. Lawn care starts with a soil test. If you wait until spring to send in soil for a soil test, you may find yourself with a lengthy wait, as labs are inundated with requests as soon as the soil is workable. A test done in the fall gives you a chance to start improving your soil over the winter when you have time to affect beneficial changes.If you didn’t do one in the spring, do it now. The $18 test from UMass tells you what your soil needs to grow what you want to grow. They give you specific recommendations for improving lawns, gardens, whatever you ask about. Do it now and you’ll have plenty of time after you get the results back to add lime, or fertilizer or whatever is recommended by the experts in October or November.
Support migrating pollinators and other birds as they travel through your backyard on their way to a winter home. Here are a few tips on how to help them on their way:
Hummingbirds may travel up to 2,000 miles to Central America. A hummingbird feeder in your garden is a welcome refueling stop for them. Monarch butterflies are heading south toward Mexico and southern California, flying up to 3,000 miles. If you don’t have them already, plant native milkweed and late blooming nectar plants such as goldenrod and asters to feed them.
Migratory songbirds need you to plant trees and shrubs to provide them with a place to roost and to refuel on berries or insects during their travels.
You can read more of Betty's horticultural advise on her website, www.BettyOnGardening.com. She is a lifetime Master Gardener.
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