September – October Gardening Tips

Helpful tips for gardening in the Triangle in September and October.

Flowers

• 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.

• Buy spring-flowering bulbs, but don’t plant these until the soil temperature drops below 60 degrees – usually in November. Store the bulbs in the refrigerator until ready to use.

• Continue to divide plants like hosta, daylilies, phlox and Shasta daisies and replant or share these with a friend.

Fruits and Vegetables

• Fall is a great time to plant fruit tress 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.

Lawns

• 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.

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.

Insects

• 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.

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.