September

Things to do in September

Fertilize:
Feed chrysanthemums every 2-3 weeks until buds appear, then weekly until buds show color. Fertilize roses, gardenias and magnolias.

Water: Water trees and shrubs deeply and slowly.

Divide:
Transplant after dividing: Amaryllises, Callas, Cannas, Daylilies, Irises, Liriope, Wood Ferns.

Soil:
Test soil every 3 years to help plan fertilizer applications.  Start a compost pile with fall leaves and yard debris; shred with lawnmower.  Replenish mulch in beds.

Lawn Care:
Watch for brown patch in St. Augustine turf as temperatures cool.  Lawns with a history of the disease should be sprayed in late month and again in 3 weeks with Terraclor or Daconil.  Early morning is the best time to water lawns.  Mow every 5-7 days, leaving the clippings on the lawn.

Diseases/Pests to look out for:
Watch roses for blackspot and mildew.  Fall webworms are easiest to control when treated early with Bacillus thuringiensis (Bt).

Prune:
Remove dead and damaged wood from shrubs and trees.  Lightly prune pyracanthas so berries will show.


Things to plant in September

Flower Plants:

  • Ajuga
  • Alpine Aster
  • Wax Begonia
  • Boltonia
  • Butterfly Weed
  • Calico Plant
  • Candytuft
  • Chinese Forget-Me-Not (Cynoglossum amabile)
  • Cockscomb
  • Cornflower
  • Dianthus
  • Daisy (English, Shasta and Painted)
  • Euryops
  • Impatiens
  • Larkspur
  • Liatris
  • Lobelia
  • Petunia
  • Phlox (divaricata and paniculata)
  • Obedient Plant (Physostegia)
  • Salvia (perennial types)
  • Sedum
  • Stock
  • Stokes’ Aster

Flower Seeds:

  • Alyssum
  • African Daisy (Arctotis)
  • Balsam
  • Bluebell
  • Bluebonnet
  • Calendula
  • Castor Bean
  • Cockscomb
  • Columbine
  • Cornflower
  • Cosmos
  • Daisy
  • Delphinium
  • Four-o’clock
  • Hollyhock
  • Larkspur
  • Liatris
  • Marigold (French)
  • Poppy
  • Snapdragon
  • Stock
  • Sunflower

Bulbs:

  • Allium
  • Amarcrinum
  • Calla
  • Autumn Crocus (Colchicum)
  • Cooperia
  • Daylily
  • Dietes
  • Hardy Cyclamen
  • Spider Lily (Hymerocallis)
  • Liriope
  • Louisiana Iris
  • Ipheion
  • Lily
  • Lycoris
  • Oxalis
  • Monkey Grass
  • Rain Lily
  • Scilla
  • Watsonia

Purchase tulip, crocus, hyacinth and daffodil bulbs to pre-chill.

Vegetables:

  • Early-Mid Month: Beans, Peas (English & edible pod), Summer Squash
  • Mid-Late Month: Broccoli, Cabbage, Cauliflower, Chinese Cabbage, Collards, Garlic, Kohlrabi.FRUIT: Prepare soil now for winter fruit tree planting


Other things to do

Trick Poinsettias into holiday bloom.
Beginning on the fall equinox (September 21/22) make sure potted plants get 14 hours of darkness every 24 hour period.  Use a water-soluble fertilizer mixed about 1/4 strength with every watering.  Plants should show color around Thanksgiving.  At that point, restore them to bright, indirect sunlight and cut back on fertilizer.

Courtesy of the Garden Guide for Austin & Vicinity, published by the Travis County Master Gardener Association, copyright 2000-2002.