Planting

• September is a good time to set out landscape plants. Shop early to find the nicest shrubs.
• When planting containerized plants, try to be certain to disturb or “open up” the plants’ root ball.
• Set out new chrysanthemum plants this month.
• Plant pansies to add color to your yard in the autumn, winter and spring months.
• Groundcovers will become well established if planted now.
• Transplant any evergreen trees or shrubs that need moving this month.
• Plant the following fall vegetables in September: mustard, onion, radish and turnip.

Pruning

• Do NOT prune shrubs in September or October..
• Remove “weed” or unnecessary trees from your landscape.
• Root prune any trees or plants you plan to move next spring.

Spraying

• Spray the following landscape shrubs for the following insect pests: arborvitae, hemlock and juniper(spider mites), azalea and pyracantha (lace bug) and euonymus (scale). .
• Spray for peach tree borer on your nectarine and peach tree trunks.
• Continue with rose spray program.
• Keep a close eye on all fall vegetable plants. Insects and diseases are more severe in the autumn.
• Control the following woody weeds by spraying the recommended herbicide: trumpet creeper, and blackberry.

Lawn Care

• Tall fescue and bluegrass lawns should be seeded this month. Remember to mulch the newly seeded areas with wheat or barley straw. Keep watered.
• Fertilize and lime your tall fescue lawns according to soil test results.
• Do NOT fertilize zoysia now.
• Homeowners can apply an insecticide for lawn grubs in early September if needed.

Propagation

• Spring flowering bulbs can be divided and replanted this month. Daffodils will be the bulbs that most likely need this consideration.
• Divide peonies.

Specific Chores

• Clean up garden sprayers and lawn equipment if not in use.
• Prepare house plants to reenter your home. Check them carefully for insect pests.
• If you do not have a fall vegetable garden, it is a good time to chop, burn or discard dead vegetable plants.
• Look for spring flowering bulbs to plant in October.
• You can get last year’s poinsettia to flower by placing it in total uninterrupted darkness for 15 hours a day, starting the last week of the month and continuing until colored bracts appear. Give them plenty of sunlight during the day.

Lawn Care
•    Treat all lawns for grubs with the recommended insecticides.
•    1/3rd of the growth should be removed when mowing warm season grasses.
•    Try to change direction when mowing your lawn.  This will help strengthen the roots system and expose different sides of the plant to sunlight.

Fertilizing
•    Be sure to fertilize strawberries with nitrogen this month.
•    Do NOT fertilize shrubs this month.
•    Now is a good time to take soil samples from your lawn especially if you plan to put out cool season grasses.  Soil boxes can be picked-up at the County Extension office.

Planting
•    Vegetables to be planted in August: beets, Chinese cabbage, cucumber, kale, kohlrabi, lettuce, mustard, radish, rutabaga, spinach, squash, and turnips.
•    Transplant broccoli, cabbage and cauliflower plants in mid-August.
•    Continue repotting overgrown houseplants.
•    Plant pansy seeds in flats this month so they can be transplanted to the landscape in September.
•    Perennial seeds to sow this month: hollyhock, delphinium, and stokesia
•    Spider lily, colchicum, and sternbergia bulbs should be planted this month.

Pruning
•    Late summer is NOT a good time to prune trees and shrubs because pruning will stimulate new growth.  That new growth will not have enough time to harden before it turns cold.  Late January and February are the best times to do major pruning.
•    Any dead or diseased wood can be pruned out anytime of the year.
•    Excessive growth on wisteria vines should be stopped to encourage blooms.  Cutting back runners and root pruning can do this.  Use a sharp spade and insert the blade to its full depth in a semi-circle about 6 feet from the main stem.

Spraying 
•    Watch shrubs for the following insects: spider mites, and lace bugs.
•    Use recommended herbicide to control poison ivy, honeysuckle, greenbriar, kudzu, trumpet creeper, and wisteria if desired.
•    Continue with rose spraying program.
•    Continue fungicide program for fruit trees and bunch grapes.
•    Peach and nectarine tree need a trunk spray for peach tree borers at the end of August.
•    Spray the following vegetables if insects are observed: broccoli, cabbage, cauliflower, and squash.
(Pesticides should be used sparingly!  Use only when needed and always follow the label)

Other Activities
•    Prepare a planting plan if you intend on doing some fall landscaping.
•    Now is a good time to construct a compost bin, if desired.
•    Irish potatoes can be dug up this month.

(From: http://www.ces.ncsu.edu/Gardening+Calendar+August/)