Fall Landscaping


by Elmer Krehbiel, Master Gardener
September 12, 2003

The fall months should be the most desirable time of the year to develop or improve the landscape and flower gardens. During early fall, a compost container should be constructed for the residue of summer plants and leaves that will be available in a month or two.

This weekend is about the latest time to sow Bermuda grass seed before cool weather, to patch an old lawn, or start a new one.

Now is the best time to aerate the lawn so the water and fertilizer elements can easily move down to the root zone of the grass during the fall and winter seasons. If water and fertilizer dont penetrate down to the root zone, they are wasted and the run off pollutes our streams.

Do not apply an excessive amount of fertilizer on the lawn. One pound of nitrogen per 1,000 square feet should be sufficient. It could be N-P-K+S a ratio of 3-1-2+S. Calculate by dividing 1 by the percent nitrogen. Example: If it is 15-5-10+S, divide 1 by .15 = 6.6 pounds of the mix from the bag to apply; or 18-6-12+S, divide 1 by .18 = 5.5 pounds of the mix from the bag.

Sulfur counteracts the alkaline clay soil and salty water. Our plants would be healthier and more productive if we had sufficient rainwater for them. If the grass is dark green and growing too fast in the fall, it will be too tender and susceptible to disease, insect, and freeze damage. If the lawn grass is mowed too low, the plants will be stressed and susceptible to those as well. Bermuda grass should be cut about two inches high, and St. Augustine about three inches high.

New perennial plants should be set this month, so they have time to develop a normal root system before winter.

The perennial flowers that should be dug, culled, divided, and replanted now are: ajuga, cannas, daisies, daylilies, bearded iris, Louisiana iris, oxalis, etc. Each stem of the canna clump should be pruned even with the ground after the flower fades. The cannas plants should be reset in fertile-organic soil each year during September or March.

Now is the time to buy tulip, hyacinth, and narcissus bulbs and place them in a refrigerator for about two months before planting them in containers or the garden beds.

Hybrid tea roses may be pruned a little during this next week. Then apply fertilizer and water to develop a fall crop of flowers.

If you plan to sow some wildflower seeds, I would suggest that you think about how they are reseeded in nature. They need low- to-medium-fertile soil with good drainage. They also need to be in full sunlight. If the soil has been tilled, firm and seal the surface with water. Then scatter the small seeds on the surface and keep the soil surface moist until seeds sprout. If seeds are too deep, they will germinate and die.

We have sown Texas bluebonnet seeds in a front-yard flowerbed for many years. We scatter the seeds on the surface, then with a leaf rake cover them lightly and spray with water each day or wait for a rain. If the soil is moist, the seeds should germinate in about one or two weeks. Each year, some volunteer plants develop too early and the heat scorches them. They will need moisture each week, but older plants need moisture only once a month or so. Inspect the leaves for stress (they will be curled up). Cultivated wildflowers usually develop blooms two weeks earlier than those along the roads and in pastures.

Dr. Elmer Krehbiel is the former President of Keep Brazos Beautiful. See his column in The Eagle.