Whats the big deal about endophytes?
For decades, plant researchers have been breeding resistance into our most important commercial crops and home-garden favorites. You can now grow wilt-resistant tomatoes, virus-free potato seed and rust-resistant asparagus. And now some lawn grasses are home to a endophytic fungus which is literally poison to many of the insects that eat your lawn!
An endophyte is a plant that lives within another plant. This particular fungus lives within certain grass varieties, including the components of brand seed mixtures, and is transmitted through its seed. One to five weeks after the grass seeds germinate, the mycelium, or vegetative filaments of the fungus, migrate to the lower part of the stem. Insects that feed on the grass are poisoned by the fungus.
The endophyte causes no harm to the host grass, and it does not disrupt the ecological balance of the healthy lawn. In fact, scientists have observed that endophyte-host grasses grow larger and faster than regular grass.
The endophytes make lawns invulnerable to webworms, billbugs, armyworms, cutworms, aphids and some weevils. Even chinch bugs, which can quickly destroy a fine lawn, will not eat grass thats infected with the dreaded endophytic fungus.
In a New Zealand experiment, nearly all the grass seedlings without endophytes were killed by weevils in only 8 days
but 80% of the endophyte-host grass survived. It is believed that the endophytes produce alkaloids which are toxic to grass-eating insects.
Bottom line on endophytes: By growing an endophyte-host grass like you greatly reduce the risk of insect infestations and the resulting need for insecticidal sprays.
What is thatch, and why should I care?
Thatch is not, as many people believe, just a collection of grass clippings caught between blades of grass. Thatch is primarily grass root stolons and rhizomes. In a healthy lawn, and soil microorganisms break down the thatch naturally.
But prolonged and frequent use of chemical fertilizers make your soil inhospitable to worms and other beneficial soil critters. Frequent shallow watering causes grass roots to grow at the top ½ of soil, creating ever thicker layers of thatch.
A thin thatch layer is okay it acts almost like a mulch but when it gets thicker than 1/2, it suppresses growth of grass, keeps water from penetrating the soil, and becomes a perfect medium for fungus. Bluegrass is more prone to develop a thick thatch layer than other grasses.
What to do? Rent a power dethatcher to pull up the tough, tangled thatch. (Early fall is the best time to do it; springtime is okay, too.) Stop using chemical fertilizers. Stop watering your lawn; if you cant resist, water long and deeply, not more than once a week. Apply a good organic lawn fertilizer such as Lawns Alive! twice a year to feed your lawn, to encourage deep roots, and to restore earthworms and other biological activity to your soil. If you replace your bluegrass lawn, use a thatch-free grass like
How can I tell if my lawn has thatch?
Using a spade or knife, cut a 3-inch deep plug or sample from a typical lawn area. Examine the sample for a brown to yellow-tan layer, starting at the base of the grass stems. There will be little soil in this layer, just a dense tangle of roots. If your lawn is bluegrass, if your lawn was started from sod, or if you use chemical fertilizer, you almost certainly have a thick build-up of thatch.
How short should I mow?
We recommend mowing at 3 height. When you cut off more than 50% of the grass blades length, the plant is considerably stressed. Grass with longer blades have more ability to photosynthesize and they grow stronger roots, which are better able to feed and support the plant. Taller grass is also better able to withstand drought and summer heat. And since many weeds need light to germinate, weeds are suppressed when the soil is shaded by taller grass. As a rule, try to mow when the grass has grown by 50%, so you dont have to cut off more than 1/3 of the blade.
My friends disagree on whether to bag grass clippings. What do you recommend?
Grass clippings decompose quickly, contribute to good habitat for beneficial microorganisms, and most importantly, return nitrogen to the soil. Within two weeks after mowing, according to some studies, the clippings are contributing nitrogen to the lawn. In some cases, clippings add as much as 1.8 pounds of nitrogen per 1,000 sq. ft. Since nitrogen is the most expensive component of all lawn fertilizers, it pays to leave clippings except when the grass is so tall and thick that it mats after mowing.
How do you overseed a lawn?
First, get rid of thatch and weeds on the parts of your lawn to be oversown. Use a hard steel rake and work it back and forth across the sore spots on your lawn. Or rent a power rake or a power dethatcher. Youll have plenty of organic debris for the compost pile!
The rake or dethatcher will create shallow grooves in the soil which will catch the new grass seed that you spread. Scatter the seed, rake it in, and water it as you would any new lawn.
The best time to seed is in late summer. Weather is ideal, relatively few weeds are sprouting, and its the best time to mend your lawn.
My lawns too far gone for overseeding. How can I start from scratch?
A new lawn is a big-time, long-term installation and will last at least 15 to 20 years if it is well cared for. But keep this in mind: now is when it pays to do the most for your lawn, so make the extra effort and spend the extra money to start your lawn off right.
Late summer and early fall is the very best time to build a lawn. Time your activities so you can give the lawn at least a month, preferably a month and a half, of good growing time before frost.
If you have (or can rent) a tractor and a tractor tiller, you can till your old lawn grasses, weeds and all. Its a relatively simple way to begin your lawn renovation.
Another way to start is with a power sod cutter. Its hard to use, but it cuts a 12-inch wide strip up to 1-1/2 inches deep. And it literally cuts anything growing there, with most of its root system. Then you can rollup the sod and take it away or compost it.
After removing the sod, till the area and break up the compacted soil. Add Fall Lawns Alive! fertilizer. If the soil is particularly poor or has had problems with compaction, add at least 2 inches of peat moss, leaf compost, or other organic material. And add lime if a soil test shows the need.
Till the amendments into the top layer of soil, then smooth the soil bed with a roller. Wait a while for the soil to settle, then fill in the low spots, cut the high spots and roll it again to get a nice, smooth, even surface.
Choose a good, low-maintenance seed mixture appropriate to your lawn use and climate. For most urban and suburban lawns, we recommend Turf Alive! III, an excellent blend of hard-wearing semi-dwarf tall fescues with built-in disease resistance and deep roots. For northern regions, we recommend Northern Turf Brand.
Using a rotary spreader, spread half the seed in one direction, then spread the rest in a direction perpendicular to the first. Rake the soil a little bit to incorporate the seed into it. Use the roller again so the seed makes firm contact with the soil. Then water thoroughly!
And water some more!
The seed needs constant moisture until its established. Then you can cut back to several times a week. When the weather cools and the lawn goes into its winter dormancy, you can relax and look forward to next years superior low-maintenance turf.
Lawn Q&A, Part One
Compliments of , Garden Alive!