NEIGHBORHOOD GARDEN FOR AUGUST 8, 2009

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GARDENING IN AUGUST

BY GEORGE EDGAR

1.       August 20th to September 20th is the best time of the year to plant new grass or overseed your lawn with Turf Type Tall Fescue (Tall Fescue Lawn Calendar, NebGuide #G558.) and September 1st to October 15th for Kentucky Blue Grass.(Kentucky Bluegrass Lawn Calendar NebGuide #G517). This time of year you will not have competition from lots of weeds waking up, and the soil temperature is warm so grass seed will germinate fast. If you are overseeding your lawn, core aerate to open up the hard clay soil, wait a day or so, and then sow your seed. Rake the seed or pull a piece of chain link fencing over the lawn so the seed drops in the holes.

          The worst thing that can happen to the new seed is for it to dry out before germination. This time of year you will have to water at least once a day and if it is hot and dry probably twice a day. Keep the seed moist but not sopping wet. Mulch or some kind of row cover or burlap will help to keep it moist and avoid poor germination.

          Buy the best seed you can afford as your lawn will never look any better than the seed you plant.  Buy quality seed that is for our Midwest area and disease resistant. If you use disease resistant cultivars you will save money over the long run since you will not have to purchase lots of fungicides to combat disease problems. Look at the package and check the label for the % of crop seed (looks like weeds in your lawn) and weed seeds. And get a blend of 3 or more cultivars so if a disease wipes out one cultivar it won’t wipe out the whole yard. Grass seed purchased from a local garden center or a local supplier will most likely grow better in our Nebraska clay soil and survive our hot dry summers and cold windy winters. Most national brands sold in a box or bag in discount stores, hardware stores, box stores and some garden centers are packaged for sale in many sections of the country and may have been grown in the South. Nebraska certified seed with the blue tag is the best for Nebraska homeowners.

2.       Do not fertilize most trees and shrubs after the first week of August. Fertilizer on trees and shrubs will prompt new growth that will not mature by the time we get a frost and thus will not be hardy enough to withstand a normal Nebraska winter.

          Also, after a tree is 5 years old usually it does not need additional fertilization, if growing under normal circumstances. In Nebraska we have good healthy soil. Clay soil can get hard when it is dry but it is full of nutrients. If a tree is in the yard or close to it, every time you fertilize your lawn you are indirectly fertilizing your trees, as the major feeder roots are in the top 12 to 18 inches of the soil and go way out beyond the drip line.

          If your tree is in the lawn area, every time you water your lawn you are also indirectly watering your trees, and your trees need a lot less water than your lawn. Just be careful when watering and do not allow your sprinkler to hit the trunk, especially if you have an automatic system. Just under the bark is the cambian layer where all the nutrients go up and down. You can injure that cambian layer and impede the flow of nutrients up and down the tree if you have an impulse sprinkler that hits the tree in the same place twice a week or even once a week over 10 years. Most trees that are outside your yard where you water, do not need additional watering unless we are having a severe drought. By this I mean it has not rained for 4 to 5 weeks.

3.       July 1st to August 15th is not a good time to put a high nitrogen fertilizer on your lawn, especially fescue. Low nitrogen with high iron content (10%) is ok and will green up your grass. If you have adequate nitrogen, iron is what will make your grass green in our clay soils. Make sure every application of fertilizer you put on has iron in it. This makes a big difference in our clay soils.

          I used to recommend the application of a “Weed and Feed” product about Memorial Day. However, this application on Turf Type Tall Fescue grass may promote disease. If you applied a pre-emergent crabgrass preventer with slow release fertilizer, that is usually enough for the spring and summer. Turf specialists at the University of Nebraska-Lincoln Extension Service say that “susceptibility to brown patch disease in Turf Type Tall Fescue between June 1 and August 15 is often related to heavy shade or over fertilization with nitrogen.” (Tall Fescue Lawn Calendar, NebGuide #G558.)  They recommend application of a pre-emergent in mid-April with fertilizer, application of a regular lawn fertilizer about Labor Day, and then a winter or fall lawn food after Halloween.

          The nitrogen content in most “Weed and Feed” products is from 28% to 32%. If you do decide to use it, do not apply after the Fourth of July. The hot weather during the summer time encourages your lawn to go somewhat dormant and the application of a high nitrogen fertilizer in July or August may burn your grass. Then you have the cost of re-seeding.

          This time of year set your mower as high as it will go so the hot sun does not dry out or burn the crown. Let the taller grass provide some shade. Remember the shorter you mow your grass the more often you have to mow it because cutting your lawn stimulates growth. Your next application of fertilizer should be around Labor Day. Copyright 2009