Helpful tips for gardening in the Triangle in September and October.
• Remove tired and leggy summer-blooming annuals and replace these with colorful cool-weather flowers like pansies. Spray these with a repellent if you have deer problems.
• Now is the time to plant new perennials. Add a slow-release fertilizer lower in nitrogen so you don’t encourage top growth. Make sure the plants are well watered before and after planting.
• Remove and store summer blooming bulbs before the first frost.
• Continue to divide plants like hosta, daylilies, phlox, and Shasta daisies and replant or share these with a friend.
• Plant a bulb on its side if you are unsure which way is up. The plant will always grow upright. Wait until the soil temperature drops below 60ºF – usually in November – before planting spring-blooming bulbs. Buy them now, but store the bulbs in the refrigerator until ready to use.
• Deadhead roses and water weekly. Clean up debris in the rose bed.
Fruits and Vegetables
• Fall is a great time to plant fruit trees and blueberries.
• Vegetables such as mustard greens, onions, radishes, turnips, and more can be planted in September.
• If you don’t plant fall vegetables, consider planting a cover crop of annual rye or clover. This will add nitrogen to the soil, control weeds, and be instant compost when you turn it over for spring planting.
• Try planting vegetables in containers so you have easy access to them.
• Cut back perennial herbs to encourage better growth next year.
• September is the time to renovate your lawn. Core-aerate and add lime. Tall fescue and bluegrass lawns should be seeded now. Remember to mulch any newly seeded bare-ground areas with wheat or barley straw. Keep watered. Add a winterizing fertilizer in late October or November.
• Do not fertilize Bermudagrass, Zoysiagrass, or Centipedegrass. Let these go dormant.
• Apply pre-emergent herbicides when the temperature drops below 50 degrees. Do not apply herbicides on newly planted grass.
• Watch for cool-season weeds. Two of the worst are wild onion and wild garlic. Hand pulling is often ineffective. Digging is more effective and chemical control is another method.
• Evaluate other lawn options if your grass continually struggles. Try ground covers or new landscaping.
• Keep leaves off the lawn which can damage the turf.
Trees and Shrubs
• Fall is the best time to plant trees and shrubs. They put down good root growth in the cooler weather. Remember to keep these watered.
• Limit pruning woody plants until they acclimate to the cooler season. Pruning now will encourage new growth. Prune only for minor shaping of the plant.
• Premature fall color or premature leaf drop could be a sign of stress on the tree. Determine the cause of the stress – injury, lack of water, poor nutrients – and remedy accordingly.
• Butterfly larvae need to be identified before spraying any insect control products this time of year, especially on flowers and herbs. If not, you may kill a future butterfly.
• A number of insects start to make an appearance including fall webworms, fall armyworms, azalea stem borers, and two-spotted spider mites.
• Control scale and mealybugs with horticultural oil. Try a proactive treatment 3-4 times a year on trees and shrubs to prevent this.
• Fire ants begin to forage with the cooler weather. Once they are in this stage you can apply bait around the mound.
• Prune out and remove disease-infested branches and dispose of them so the disease doesn’t infect next year’s growth.
For a complete list of garden maintenance activities, visit the NC Cooperative Extension web site at www.ces.ncsu.edu.
For lawn care go to the NC State Turf Files at www.turffiles.ncsu.edu.