Its only August and the dog days of summer continue, but a change in seasons will soon be upon us. While xeriscaping is popular in our region, a home lawn can still be an important part of the landscape. Given the semi-arid climate of this region, however, water conservation is important when managing turf. Appropriate treatment of the turf in these latter days of summer and the fall will improve drought tolerance, promote turf health and set up favorable conditions for the next season. For detailed information pertaining to specific grasses and renovating a lawn, refer to Fact Sheet 7.202 - Lawn Care and 7.241 - Renovating the Home Lawn . The following information will focus on care of common cool season grasses (e.g., Kentucky bluegrass) in established lawns.

Continue to mow the lawn to a height of 2.5 - 3.0 inches being careful not to remove more than 1/3 of the grass height at any single mowing. Allow the clippings to fall back onto the lawn as they provide a good source of recycled nutrients and organic matter and reduce the need for fertilization. Water the lawn in the late evening or early morning hours and provide enough moisture to reach the root zone. As climatic conditions are unpredictable in our region, watering schedules must frequently be adjusted. A simple method to assess when the lawn needs watering is when footprints on the turf are still visible after 30 - 60 minutes.

Over-fertilization in the summer months is not recommended but fall fertilization 2 - 3 weeks before the ground freezes and while the grass is still green is suggested. A ratio of 1 lb of nitrogen/1000 square ft of lawn is generally recommended, but may be reduced by 1/4 to 1/3 if grass clippings are left on the lawn. As the temperature decreases, the time between waterings should be increased. During the winter months, watering may be as infrequent as once every 4 - 6 weeks in the absence of rain or snow. Winter watering is most beneficial when ground temperatures warm up enough to allow moisture to soak into the soil. Since automatic sprinkler systems are generally turned off during this time, alternative methods should be used.

Core cultivation is usually performed in the spring in our region but the lawn can benefit from additional fall aerification. This will help water and nutrients reach the root zone, reduce thatch formation and alleviate soil compaction. It is also good to over-seed the lawn at this time. Germination of over-seeded grasses in the late summer/early fall can occur as long as ambient temperatures remain above freezing.

Q: Some of the leaves on my aspen trees have little black spots on them. What causes them?

A: You probably have a fungus called Marssonina which is a common leaf spot disease on aspens. It appears as dark brown flecks, sometimes with yellow halos but immature spots may have a white center. In spring, and in warm wet weather, microscopic spores can be carried by wind to infect new leaves. Early infections are seldom serious but with favorable weather conditions, secondary infections can cause premature leaf loss later in the season. Fall pruning of affected branches and twigs and raking of infected leaves can help reduce the disease next spring. Water early in the morning so that leaves have time to dry and avoid letting sprinklers hit leaves directly. Fungicides may be used if applied early in the cycle but it will not cure already infected leaves.

Q: I have a lot of tomatoes on my vines but not many are ripening yet. Is there any way to extend the growing season for tomatoes?

A: You may construct a temporary greenhouse over the plants but it must be ventilated to prevent excess heat build up during hot days. When it begins freezing regularly, harvest any green tomatoes and wrap them individually in newspaper and store in a cool place. When you are about ready to use them, unwrap them and place them on a window sill to ripen.

Q: We have a couple of deer residing in our subdivision this summer. Are there any repellents that are effective in keeping them out of our flowers and garden?

A: Fencing would be the best. However, 6.2% Hot Sauce, Deer Away, coyote urine, and chicken eggs (a mixture of 20% eggs to 80% water) are the most effective repellents.

Some good perennials for bloom in the "dog days" of August into fall include Russian sage, sea lavender, grape leaf anemone, Siberian statice, strawberry wood sorrel, Achillia millifolium - 'Red Beauty', white coneflower - Echinacea purpurea 'White Swan', and rudbeckia fulgida sullivantii 'Goldstrum' - orange coneflower.

Prune excess vegetation and flowers on vegetable crops to help mature the remaining fruit before frost.

Heritage and Redwing are two varieties of fall bearing raspberries well adapted to the Front Range. Fall-bearing raspberries produce canes from roots and bear fruit the first season. Unlike summer-bearing varieties they don't usually require any support or trellising. Mulch your raspberries to keep the soil moist and prevent leaf scorch. After the fall harvest the canes should be mowed to the ground.

Scarlet sage is a salvia and like culinary sage it is a member of the mint family. The clear red blossoms are a favorite with hummingbirds. A native of Mexico and Brazil where it is a perennial, it is grown here as an annual.

Ornamental grasses can add texture, sound and movement to your garden, in all seasons, even winter! They are easy to maintain and will grow in poor soil. Fall is a good time to see the grasses at maturity and to pick out varieties you might like to add to your landscape. Visit the W.D. Holly Plant Environmental Research Center on the CSU campus and check out the grass garden or look for different varieties at local nurseries.

The authors have received training through Colorado State University Cooperative Extension's Master Gardener program and is a Master Gardener volunteer for Larimer County.

Gardening and Insect Fact Sheets are available on-line by clicking HERE.

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This page updated:  August 23, 2004