September To Do List, Zone 3
Our first frost is likely to come this month. Stay tuned to the television and newspaper forecasts to find out exactly when. Prolong the growing season by throwing a sheet or other non-plastic material over your annuals and vegetables. In fact, for vegetables, you can cover them indefinitely with any very light fabric and anchor the corners with bricks or stones. It lets in sun and rain, but prevents light frosts from doing any damage. Plants that are summering outdoors need to be checked for insect pests before you bring them indoors. Earwigs, slugs, spider mites, aphids, and weevils can easily be brought indoors to continue their destruction. Use a soap spray to clean up plants.
- Now is the time to plant lots of tulips and daffodils. Add amendments such as compost, bone meal or high phosphorus fertilizer to the bulb beds and work it down to a depth of 12 inches or more before planting.
- Squirrels “read” the disturbed soil and marks you leave when planting their favorite tulips and crocuses. Outwit them by concentrating spring bulb plantings in large groups and disguising your marks by flooding the soil surface with water, then covering with leaves topped with some shrubby branches.
- Plant Asiatic and Oriental lilies in late fall to ensure flower bud set in the spring.
- With a shovel or fork, lift clumps of summer phlox, hostas and Siberian irises and divide with a sharp spade or knife. Tease apart fleshy roots of daylilies.
- Autumn is the only time to move clematis or honeysuckle vine. Both vines begin extending leaves and shoots while frost is still in the spring ground. If the vines are large, cut them back by half, and they’ll take off next spring.
- Clean up perennials as much as possible now, but leave strategic clumps with seed heads attached for attractive winter display and food for birds. Sedums, hostas, astilbes and ornamental grasses are beautiful in snow.
- Remove the debris of summer annuals, disposing of any diseased plants in the trash and composting healthy plants.
- Throw seeds of hardy annuals where you want them to bloom next year. Larkspur, poppies, cleome and cosmos will frequently take root from seeds sown in autumn and conditioned under winter snow.
- This time of year, the leaves of Black Eyed Susans often turn partly or completely black. This is caused by a fungal pathogen. It’s best to remove infected stems and leaves at the end of the season. Next year, thin plants and remove volunteer seedlings to provide good air movement around plants. Look for leaf spots early in the season and pinch off infected leaves. Never remove more than 1/3rd of the plant’s foliage.
- Sow wildflower seed for spring bloom.
- You can plant ‘Icicle’ pansies in spots where summer annuals have been cleared out. They will bloom until December, and then lie down for the winter. Cover them with evergreen cuttings until earliest spring, when they’ll be ready to sprout new buds.
- You can harvest herbs through the fall. Freeze in ice cube trays in water and put in plastic bags for the freezer or dry them in whole leaf form in a dark, cool cabinet.
- If you’ve left potatoes and onions in the ground, dig them now. Let onions air dry in the open for a few days and then bring them inside to an airy, dry, cool spot. Immediately bring potatoes indoors to a spot where they will receive no light.
- Continue to harvest tomatoes, even before they are completely ripe to avoid getting blight spots on them. They are edible, but the spots will cause them to rot sooner.
- If frost is predicted, be prepared with frost blankets, cardboard boxes, and plastic and clay containers to protect the plants at night. Remember to remove the plant protection during the day.
- As long as the temperatures remain mild, you’ll extend your growing season by continuing to harvest zucchini, cucumbers, beans, and lettuce in the younger stages.
- Plant garlic for harvest next summer.
- Root vegetables such as carrots and parsnips are sweeter after hard frost and can be harvested all winter.
Trees and Shrubs
- Make sure trees and shrubs get at least an inch of water every week, especially evergreens. They will suffer through winter if not well hydrated in the fall.
- Wait until the leaves of deciduous trees and shrubs change color to transplant them. Transplanting earlier may send them into shock. After planting, mulch well and provide an inch of water a week until the ground freezes.
- Autumn is a good time for planting evergreen trees and shrubs. Be sure to water them well before the ground freezes.
- Ever-bearing raspberries produce a fall crop on the top half of the canes. After harvest, cut out the top of the canes, leaving the bottom half to produce a crop next summer.
- Use generous amounts of anti-transpirant sprays on needle evergreens and broadleaf evergreens, such as euonymus, Japanese pieris and rhododendrons. The waxy coating helps to preserve moisture and prevent winter windburn and sunscald. Your Christmas tree would love a coat, too.
Lawn and Turf
- Now is the time to fix your lawn’s bare spots. Rake up any debris, rough up the soil and sprinkle fresh seed. Mulch with a light covering of straw or grass clippings.
- To renovate an entire lawn, rent a slit seeder and over seed. Water well and keep watered through the fall.
- Lawns benefit from fall fertilizer. Feed early September and again in mid to late October. Apply after a good core aeration of the lawn. Coring removes cores of soil and grass, opening holes for vigorous root growth on compacted or thatch-ridden turf. Cores will decompose on the lawn in a couple of weeks.
- Keep ahead of raking or blowing leaves off the lawn. A thick layer of fallen leaves can impede the growth of grass, depriving it of sunlight. You don’t have to rake up every last leaf; a shortcut is to mow, shredding the leaves.