September is a busy month in the garden. Weeding is not yet over, and our fall cleanup begins with cutting back everything that has finished blooming and dividing perennials. Now is a good time to take cuttings for next year’s garden. Prepare the vegetable garden for fall planting. Purchase floating row covers to use on tender plants as temperatures begin to dip at night. Have your camera ready to document spectacular fall color changes.
- Sow lettuce seeds directly in the garden when temperatures are below 80 degrees, or start seeds in flats and transplant them to the garden after three to four weeks. Stagger your transplanting schedule a week apart and use row cover. You may be harvesting lettuce into November and December.
- Side dress tomatoes and peppers with compost and water deeply. Once nighttime temperatures dip into the low 70s, you probably aren’t going to get any new fruits forming, but you can speed up ripening of the existing green tomatoes. Pinch off any new flowers.
- Pick herbs on a dry morning after the dew has evaporated, when the oils are most concentrated. If you are drying herbs, keep them cool and dry, with good air circulation. Wash herbs only if they are dirty or have been treated with chemicals.
- Plant blueberries at the end of the month. Mulch with pine needles and /or oak leaves to maintain acidic soil.
- The flower for September is the aster. It’s been blooming since midsummer and will last up to frost. Keep it pinched back to stay bushy and keep producing flowers.
- Keep up with weeding. Many weeds sprout in the fall and must be pulled before they go to seed.
- Perennials need to be divided every few years for healthy plants. Examine leaves for aphid damage and or fungus. If it exists, cut the leaves & dispose of them.
- If your peonies need dividing, do it now. Replant the crowns shallowly—just an inch or so below the surface.
- This is a good month to divide bearded iris.
- As somewhat cooler weather moves in, be ready for the hardy appetites of warm-blooded garden pests. Voles are active breeders, often producing up to five litters a year. In warmer climates, they can breed year round. Create a basket of 1/4” hardware cloth to serve as a wrap around the roots or bulbs of prized flowers and plants.
- Warm soil temperatures and cooler nights make September through October an excellent time for planting trees and shrubs. Water new transplants deeply, then mulch out to the drip line. Keep mulch six inches away from the stem or trunk.
- When planting new trees and bushes, select the most appropriate sites. They really will grow as large as the labels say, so leave enough space and be patient.
- Yellowed leaves usually indicate an iron deficiency, whether on roses, gardenias or trees. Spray the leaves with chelated iron with a drop of liquid soap added to the mix. The liquid soap acts as a ‘sticker’ for the chelated iron, helping it linger on the plant material.
- Stop fertilizing Bermuda if you are going to overseed with rye next month. September is also a good month to lightly de-thatch Bermuda grass.
- Most turf will benefit from core aeration and de-thatching to improve water penetration, turf root growth, relieve compaction, and increase effectiveness of fertilizer.
- You only need to fertilize your lawn, once in the fall. Use a slow release fertilizer with iron and a higher potassium rating (‘K’ of the NPK ratio). Potassium will stimulate root growth and increase disease protection.
- Water immediately after applying the fertilizer to promote quick absorption.