GARDENING TIPS FOR SEPTEMBER
Annuals & Perennials
- Stake tall growing plants.
- Remove faded blooms on annuals and perennials.
- Cut brown flower stems of coneflower, black-eyed Susan, daylily and hostas to ground level.
- Mulch to retain moisture, control soil temperature and diseases.
- Control weeds. Apply granular weed-preventer in established beds.
- Wrap cheesecloth around sunflower heads to keep the birds away. Head is ready to harvest when the back turns brown.
- Fertilize established chrysanthemums and salvia with liquid plant food.
- Divide and transplant astillbe, columbines, daylilies, hostas, iris, lavender, liriope and established groundcovers.
- Plant chrysanthemums and peonies. Plant peony crowns only 1½ to 2 inches below ground level. Deeper planting keeps peonies from blooming.
- Plant pansies and violas towards the end of the month when the soil temperature is below 70 degrees and nighttime temperatures are in the 60s. For soil temperature: http://www.georgiaweather.net
- Purchase daffodil, tulip and hyacinth bulbs now and store in cool place. Plant when soil temperatures are in the 60’s or lower.
- Plant ground covers: liriope, mondo grass, periwinkle, pachysandra.
- Protect your trees. Read “Planting Under Trees”
- Take cuttings of coleus, datura, geraniums, salvia, and other summer plants to root and over winter indoors.
- Prepare area for a wildflower meadow. Kill existing vegetation. Wait a few weeks, till the area, rake and scatter meadow seed.
- Harvest fruit as it ripens.
- Spray for insects and diseases, as required. Read the label for waiting time between spraying and harvest.
- Check for scale. Spray with dormant oil after leaves fall.
- Check grapevines for mummified fruit. Pick these and dispose of them. Do not compost.
- Fertilize existing strawberries. Prepare new beds. Keep beds weed free.
- Fall weed control around fruit trees is crucial. Weeds act as hosts to over wintering insects.
- Water, if required.
- Mulch with 2-4 inches of pine straw or bark keeping it away from trunk.
Trees and Shrubs
- Remove blooms from shrub roses as they fade.
- Remove suckers from base of cherry, dogwood and crabapple trees.
- Remove dead flower clusters from crape myrtles.
- Prune boxwoods by thinning.
- Prune hybrid tea and grandiflora roses.
- Cut down and remove trees or shrubs attacked by ambrosia beetles.
- Fertilize roses. Remove black spot leaves from bush and ground.
- See annual rose maintenance schedule:
- http://ugaextension.org/county-offices/cobb/agriculture-and-natural-resources/gardeners-corner.html Scroll down
- Plant trees and shrubs. Be sure to remove synthetic burlap from ball and burlap plants. It does not decompose. Fertilize fall planted shrubs in the spring. Water deeply.
- Propagate woody shrubs and evergreens by taking softwood cuttings.
- Refresh mulch, 3 inches deep, around trees and shrubs. Keep mulch away from trunks. If planting had a disease problem, remove old mulch to help prevent disease in future.
- Pull down and destroy big webs made by fall webworms.
- Check for various pests and diseases. Spray only if practical and required. Drought may accelerate leaf drop of some plants and lessen need to use pesticides.
- Arborvitae: Needle blight.
- Azaleas: Azalea caterpillar, stem borer.
- Boxwood: Blight, spider mites
- Camellia: Southern red mite.
- Crape myrtle: Aphids, ambrosia beetles, leaf spot.
- Euonymus: Scale. Sprays applied in Spring are most effective.
- Gardenia: Whitefly, leaf spot.
- Hydrangea: Leaf spot, root rot
- Holly: Spittlebugs, caterpillars.
- Indian Hawthorne: Leaf spot.
- Ivy: Anthracnose.
- Junipers: Bagworms, spider mites, needle blight.
- Leyland cypress: Bot canker, Seridium canker, needle blight.
- Oak: Orange-stripped oakworm from now through October.
- Oak: Spray oak slime flux with a solution of 1 part bleach and 15 parts water four times, four days apart, to eliminate the odor and bacteria. This will not control the infection.
- Pine: Aphids, bark beetles, needle scale, sawfly larvae.
- Roses: Thrips, powdry mildew
- Roses: Black spot Spray every two weeks.
- Rhododendron: Canker, dieback, caterpillars, planthoppers, stem borer.
- Information on leaf spots: http://ugaurbanag.com/content/leaf-spots
- Sanitation is one of the most effective methods of maintaining a healthy garden.
- Read “Drought Damage to Trees”.
- Storm damaged tree information:
- Perform a tree survey. Form available at
Spring planted trees and shrubs need 1 inch of water per week. Mature trees need deep watering. Trees may lose up to 10% of their leaves during drought. Additional information at
The Georgia Forestry Commission’s on line service —“Ask the Arborist”. Complete a form and a certified arborist will answer questions and evaluate conditions.
- Have soil tested in preparation for seeding of fescue and adjusting pH for all turf.
- Plant or renovate fescue.
- Dethatch or aerate established fescue.
- Fertilize fescue. Fertilize Bermuda six weeks before first frost. Do not fertilize centipede or Zoysia.
- Mow grass at proper height. Keep the blades sharpened.
- Check for fall armyworm and spittle bugs.
- Apply postemergent herbicide for violets on fescue and Zoysia.
- Apply postemergent herbicides as required. Apply preemergent herbicides for cool weather weeds.
- Avoid applying herbicides to areas of fescue to be seeded or just have been overseeded.
- For detailed information on turf care and diseases go to georgiaturf.com
- Plant beets, broccoli, cabbage, carrots, collards, kale, lettuce, mustard, onions, radishes, spinach and turnips.
- Plant seeds for coriander (cilantro) and chervil. These are biennial herbs.
- Harvest vegetables regularly to prolong production.
- Collect herbs after dew has dried.
- Mulch between rows to retain moisture, control soil temperature and diseases.
- Clean harvested rows immediately to mitigate insect and disease buildup.
- Water vegetables, if required.
- Check for various beetles and bugs. Spray as required. Read the label for waiting time between spraying and harvest.
- Sow a cover crop in beds that will not be planted.
- Keep a log book of problems so they can be prevented next year.
- Get soil tests. Fall is the best time to add lime if it is required.
- Plan your fall garden. See “Vegetable Gardening in Georgia” for September and October plantings.
- Information on insects and diseases, see
WATER On November 2016 the Director of Georgia Environmental Protectiion Division issued a Level 2 Drought Response. Outdoor irrigation is permited twice a week on the odd/even schedule. Even and unnumbered addresses may water on Wednesday and Saturday between 4:00 PM – 10:00 AM and Odd addresses may water on Thursday and Sunday between 4:00 PM – 10:00 AM.
For a guide on the Drought Response Level 2 and information on exceptions
- Read “Best Management Practices for Landscape Water Conservation “
- Water slowly and deeply. Deep watering encourages root growth.
- Use drip irrigation or soaker hoses. They use 50% less water than sprinklers.
- Check your irrigation system. (1) Is the timer set correctly? (2) Are all the nozzles working? (3) Are all the nozzles the same type? There is a significant variance in water applied between rotary sprinklers and spray heads.
- Set a timer and/or use a rain gauge when watering the lawn or garden.
- Check outdoor faucets, sprinklers and hoses for leaks. Replace washers as required.
- Select plants that are drought tolerant and have low water needs. Group plants with similar water requirements in the same zone. For a listing see
- Use a rain barrel. For instructions to build one:
- Save water and use it wisely. Don’t water the lawn on windy days. Water plants, if required, applying one inch of water per week.
- Observe current Georgia watering restrictions.
Check with your local water system to determine if they have more restrictive regulations.
Burning is NOT permitted from May 1 to October1. For additional information and restrictions in specific areas
- Non-native invasive plants are a problem in Georgia and the Southeast. Its not only kudzu, Chinese privet, and golden bamboo. Become aware of these exotic pest plants and what you can do to inhibit them. Go to
http://www.gaeppc.org Click on plant list
- Pesticide storage: lable properly, store in locked cabinet.
- Dispose of pesticides correctly. http://www.walterreeves.com/tools-and-chemicals/pesticides-disposing
- Protect the environment, watersheds and sewer system by the proper disposal of grease, hazardous household products and pesticides. Go to
- Fall is the best time to kill fire ants. Treat as required. Additional information: http://growinggeorgia.com/features/2011/09/fall-fire-ant-killing-time/
- Eliminate mosquito breeding places.
- To reduce next year’s Japanese beetles, apply an insecticide now to control the grubs.
- If you spray pesticides (insecticide, fungicide, herbicide) do it in the cooler hours of the evening. Some chemical treatments are ineffective or cause injury to desirable plants when exposed to temperatures above 85°F. Read the label.
- Control kudzu, poison ivy, honeysuckle and ivy with herbicides. Plants are beginning to pull nutrients from leaves into roots thus increasing effectiveness of herbicides.
- Lightly trim back tropical hibiscus before bringing indoors.
- Start adding leaves and other materials to the compost pile. Do not add weeds with ripened seed heads. Seeds can remain viable and will germinate next year when compost is used.
- Do not use ashes from charcoal grill in the garden. Briquettes have added ingredients which may be harmful.
- Collect seedpods for craft projects.
- Spray houseplants before bringing them in for the winter.
- Root leaves of African Violets or begonias for holiday gifts.
- Furnish water for the birds. Change the water every 3 days to control mosquito breeding.
- The key to reducing problems with soil insects in the garden is to keep the site clean. Frequent cultivation will help reduce grubs, nematodes and weeds.
- Keep a log book of problems and hints to address next year.
- Prepare new beds.
- Analyze your landscape. Consider implementing water efficient principles to conserve water.
- Analyze the microclimates in your landscape. See
- Information on forest pests is available from the USDA Forest Service
- Learn about the plant nutrients found in soil and air and how they are utilized by plants.
Visit us at the Marietta Farmers Market the last Saturday of the month in September and October.
Information on fertilizing, pest and disease control, propagating, pruning, etc. is available from the Extension Office. Call us at 770 528-4070 or see our website http://www.ugaextension.org/cobb
For a soil test, bring 2 cups of dry soil to the Extension Office. Cost is $8.00 per sample, payable by check or credit card.