Expert answers common lawn questions
Attitudes about lawns are changing as gardeners looking to reduce chemical use around their homes are reconsidering just how picture perfect their turf needs to be.
Tolerance for a few weeds, combined with methods of maintaining lawns with little or no herbicides and pesticides are gaining ground as concerns about protecting family health, the environment and surrounding water quality increase.
Following are six common questions people ask about lawn care and the latest information on the various approaches homeowners can take.
How to grow grass in the shade is a popular question, said David Chinery, horticulturist with Cornell Cooperative Extension in Rensselaer County and an expert on lawn care. The problem with growing grass in the shade is that grass is a sun-loving plant.
“Grass is very hard to grow under the canopy of trees, especially trees such as Norway maples, which have a dense canopy and are very efficient in taking nutrients and moisture from the soil,” he said.
Chinery suggested trying a fine fescue grass in shady places as this grass is the most shade tolerant. If that fails, the best and most attractive solution might be a shade garden, ground cover or mulch. While this approach may not be for everyone, both ground covers and mulch are low-maintenance solutions.
Or, you can try your hand at a colorful shade garden. There are many nurseries that carry perennial plants for shade gardens such as foam flower, epimedium, bleeding heart, hosta, lamium, primula, lungwort, toad lily, trillium and many, many more. By adding compost to the area to amend the soil, planting perennials and watering consistently, you can create an attractive alternative to grass.
What should you
do about grubs?
Chinery’s first advice is “make sure you actually have a grub problem.” Some people are quick to use a pesticide without checking whether they actually have a grub infestation or reading the pesticide label. Using chemicals needlessly is expensive and environmentally unsound.
To determine if you have an infestation, cut three sides of a 1-square foot area of turf. Peel it back and count how many grubs are present. If there are more than 5 grubs per square foot, then chemical intervention may be justified to avoid dying grass and bare spots.
Timing is everything, Chinery said. Insecticides are ineffective when the insects are not active or are too large to be affected by the chemical. In order to work, the preferred insecticide — Merit — needs to be in the soil when the grubs are at their smallest. The best time to apply Merit is mid-June in our area, Chinery said. Merit moves slowly, he explained. By applying it in June, the Merit will be in the soil for several months, including when the grubs are at their tiniest.
Two weeds that are a constant source of questions are ground ivy and crabgrass.
Ground ivy, a.k.a. creeping Charlie, is a nuisance perennial weed that can quickly overcome a lawn. There is no easy control. Seasoned gardeners will pull it out by hand when they first spot it, knowing that it is an aggressive spreader.
Chinery said the best time to treat for ground ivy is October. The best results can be achieved with herbicides that contains dicamba; 2,4-D (2,4-dichlorophenoxyacetic acid); mecoprop or MCPP (2-(2-methyl-4-chlorophenoxy) propionic acid.
“Be very careful using it,” he advised. And, be responsible. Instead of treating the entire lawn area, many homeowners are opting to treat just the front lawn area, leaving backyards untreated. Another alternative would be to spot-treat or try hand-to-hand combat.
Crabgrass is the other nuisance weed to lawn lovers. While some people opt to put down a pre-emergent herbicide, which is the most commonly used herbicide in New York state, others are trying non-chemical approaches.
One such approach is the use of corn gluten products, “Some people have luck with that,” Chinery said. He cautioned that corn gluten adds quite a bit of nitrogen to the soil and should you decide to try it, forgo fertilizing at the same time.
A second approach that is gaining in popularity is keeping the lawn vigorous and dense by repeatedly seeding any thin areas with more grass. The premise is that thick grass crowds out crabgrass.
Chinery said putting grass seed down on an existing lawn once a week for several weeks can improve the density of lawns up to 90 percent. A dense lawn suppresses weed seed germination.
“Fall is the best time to over-seed. It’s not as effective in the spring,” Chinery acknowledged, adding that it is still worth trying as spring-sown seed will germinate and might be enough to out compete crabgrass.
The key is choosing the right seed. He recommended a perennial ryegrass, which germinates quickly.
“In mid-September, put down grass seed with a high perennial ryegrass content. It will come in as the crabgrass naturally dies back,” he said. The reason fall is better is that cool weather and warm soils enhance seed germination.
Remember to water the seeds and make three or more applications of seed. Applying a large amount of seed gives the competitive advantage to the perennial ryegrass.
Other actions homeowners can take to create a healthy lawn include collecting a soil sample by scooping soil from several locations in the lawn. Mix the sample together and bring about a half cup to your local Cooperative Extension office to test the pH and nutrient levels. Use this information to determine a fertilizing program.
Other simple things homeowners can do is:
-- Set the mower at a 3-inch cutting height. Mowing higher significantly reduces weeds.
-- Mow with a sharp blade. “A sharp blade will save up to 30 percent of fuel used [in the mower]. It looks better and cuts better,” he said.
-- Use a mulching mower to return the cut grass — nutrients — back to the soil.
If you would like a copy of Cornell Cooperative Extension’s brochure on over-seeding, send a self-addressed stamped envelope to David Chinery, 61 State St., Troy, N.Y. 12180-3497 or go to the Web site www.ccerensselaer.org/horticulture-program/lawn-fact-sheets.aspx.
Once considered the scourge of the well-manicured lawn, it is now trendy to grow moss. Some gardeners have taken it to an extreme and are exclusively growing different types of moss. In addition, more and more nurseries are carrying mosses.
Chinery said he encourages gardeners to grow moss in shade. “It usually grows where grass will not. It’s green. It requires very little work,” he said, adding that he has a mossy area at his home that he weeds and vacuums a couple of times a year.
Are you sold on the idea of growing moss yourself?
If you can’t embrace moss, you will need to look at the site conditions and decide what to do. Ferric sulfate (iron sulfate) can be used to control moss but the results are usually temporary. You can also try raking out the moss.
For long-term results, your first step should be to test the soil pH and create an environment conducive to grass, which is usually what homeowners are looking to grow.
Grass grows best when the pH is between 6.2 and 7.2. Remember, grass is a sun-loving plant. Too much shade is frequently at the root of a moss problem.
One solution might be to prune overhanging trees to improve air circulation and light penetration and seeding with fine fescue grass.
Watch your maintenance routine. Cutting the grass too short can contribute to moss growth. Since moss tends to grow where fertility levels are low, adding nitrogen to the soil may help.
How to repair damage done by snowplows is a common question in the spring. Rake the area smooth in preparation for seeding. Chinery recommended using a mat with grass seed woven into it or similar product that holds moisture around the seeds as they germinate. The mat “can be left in place and will decompose. The grass grows up through it,” he said. Row covers over newly seeded areas are also effective.