D | F | G | M | R | S | T | More Commonly Asked Questions

Dog Urine on Lawns
Our front lawn has a lot of dark green spots in it. Each one is at least the size of a dinner plate or larger. Is this the start of some disease?
No, it isn’t a disease. Do you or your neighbors have a female dog that likes to use the lawn for a bathroom? These spots are caused by the high levels of nitrogen in urine. When the lawn starts greening up, these spots really show. Eventually they will disappear as the rains soak the lawn…if we have rain. Otherwise, soak the spots with water, thoroughly drenching the soil. You can also use this method if excess fertilizer is accidentally dropped on the soil.

Fairy Ring
Last year we had areas of dead grass surrounded by tiny mushrooms in our lawn.  As we are expanding our lawn, having cleared some woods, and wondered if there is any type of grass that won’t be affected this way?
Unfortunately, no.  Fairy ring is the product of dozens of types of fungi that develop in soils having organic matter that is not decomposed, such as dead tree roots, where the soil is acidic. If you are clearing woods for lawn make sure to remove all the tree roots.  Remember, our Rhode Island woods are normally very acidic.

The dead area in the center of the ring you saw is because water is not able to penetrate and the mushrooms are the flower of the fungus that feeds on dead wood.  Apply a little extra nitrogen fertilizer to the area and keep it well watered for a few weeks. Or, you can dig out the area, increasing the size by one foot or so, then replace the soil and reseed. There is no chemical control for fairy ring and there is no seed that is resistant.

Fall Fertilizing
How late in the fall can my lawn be fertilized?
If you are fertilizing three times a year, the last one should be around Thanksgiving Day. This will keep the roots of your grass happy through the winter. The prior application should have been around Labor Day and the first one around Mother's Day. But, have you had your soil tested to see how much of N (nitrogen), P (phosphorus), and K (potassium) you really need…and for pH? If the pH isn't where it should be (that is, neutral), the fertilizer you apply may not be utilized optimally. Also, nitrogen, which turns your grass a nice shade of green, can lead to problems if too much is applied - and so does fertilizing at the wrong time. Be sure to follow the directions on the bag of fertilizer, and water the lawn after an application.
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General Problems
Why do we have so many problems with our lawns?
Because we don't take care of them right. We, including me, get tired of mowing every few days and so we lower the blades on the mower: close cutting creates problems. Constant removal of new growth depletes the food reserves that are needed for disease resistance so the grass becomes susceptible to a host of diseases.

We don't water properly. A deep watering less frequently is far better than a light sprinkling done daily. An inch a week is fine, it's all the lawn needs. (Tip: Place a cat food or tuna can on the lawn, when it's filled, shut off the water.) Too much water restricts root growth and encourages the growth of algae and mosses. Too little water stresses the lawn by creating shallow root growth so the grass can't resist disease. Also, we water at the wrong time of day. Water in the morning so that the grass dries by nightfall.

We don't get the soil tested to see what our lawns need. It's easy to pour on the lime then fertilize whenever the grass looks poor! Wrong. Know what the lawn needs and when to apply it. For example, excessive nitrogen at the wrong time can encourage disease.

Excessive buildup of thatch can create a host of pathogen headaches. Using mulching blades on the mower and letting the clippings rot in place will give back nutrients to the lawn. We don't sharpen the mower blades when we should, but by keeping the blades sharp we avoid tearing the grass blades, thereby preventing a lot of excessive injury.
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Moss
How do we get rid of the moss in our lawn?
Moss grows where other things won't, forming a soft mat of green that nobody appreciates in their lawn - and, sometimes, nowhere else either. There are reasons that this is happening, including compacted soil, acidic soil, soil with low fertility, shady location, or poor drainage. Chemical controls will only temporarily remove the moss; it will return until the contributing conditions are corrected.

First, have the soil tested and amend according to the recommendations you receive. Then, loosen soils that are compacted to a depth of at least 4 inches and add recommended lime and fertilizer or compost. This process will also break up the moss and improve oxygen levels in the soil. Improve drainage if the soil is moist by raising soil levels, adding sand to the soil, or installing drains. Increase the amount of light on the lawn by thinning out any trees that shade the area, which also allows for a better air circulation.

Be aware that maples and a few other trees have numerous surface roots that absorb all the nutrients in the area, thereby making it impossible for grass to grow but exacerbating conditions in which moss will thrive. If you cover these roots with soil, you could kill the tree so an alternative to grass may be needed, such as a low ground cover.

Finally, select a grass that suits your needs. There are blends available that will withstand rough playing by children and pets, grow well in shade, and even repel diseases and insects.
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Organic Lawn Fertilizer
I had a new front lawn put in last season. I applied lime in fall and I used a low number organic fertilizer in the spring. It is not greening up very quickly. Is there anything else I should apply?
Be patient. Organic fertilizers don't always work quickly. I wouldn't put anything else on for a couple of weeks; certainly apply a fertilizer again in late summer. In the meantime, you might want to overseed to fill in the thin spots.

Red Thread
What can you tell me about treating red thread in the lawn. I have checked the internet and only found chemical controls. 
Red thread (Corticium fuciforme) remains dormant in the soil until favorable conditions prevail; in hot, humid weather the fungus (Laetisaria fuciformis) grows visibly on the infected grass blades and leaf sheaths. The fungus produces thread-like strands or web-like areas of coral-pink to blood-red hyphae on the tips of brown grass blades. It favors older varieties of Kentucky blue grass, red fescue, ryegrass, and sometimes bentgrass. It thrives on soils that are low in nitrogen, so treat with a high nitrogen fertilizer, but it would be wise to have the soil tested for pH.
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Shady Lawn
We have acidic soil here and I have a large backyard that is shaded and there is a lot of rock. How can I grow grass? Most of what I have now is weeds, moss, and just plain dirt! Or is there something else I can grow?
Grass needs a pH of 6.5, ideally. Lime is the best way to raise the pH. A soil sample from your local Cooperative Extension will help to determine how much lime is needed. If you really want grass thast is well adapted to growing in shade, look for a grass called "Poa trivialis."

Sod
We had sod put down last year, and while raking debris this spring the sections just peeled away. We didn't see any grubs, just dry chunks of soil and grass. Are we going to lose the lawn?
Hard to say. Is the grass brown? Can you roll up the sections like a rug? Was the soil beneath prepared properly before the sod was installed? When installing sod, the soil should be tilled and raked free of all debris. The sod needs to make solid contact with the soil surface and extra water must be applied until new roots are established. Was the sod delivered and set down right away? Sod that is rolled and stored improperly often has a difficult time getting established. Sod should not be held more than one day in hot weather but during the winter it can be rolled and stored longer. If your sod is only coming up in a few places and the remainder is well established, you may have just a small amount that didn't make good contact and needs to be redone with fresh sod.

Snow Mold
What is snow mold? Does it happen because there is lots of snow?
Snow mold is a pathogen that occurs on turf grass. There is gray snow mold and pink snow mold, caused by different pathogens but occurring under the same conditions.

Gray snow mold, caused by a fungus that is found in most soils, is found in early spring after the snow has melted. It is common in areas where snow accumulation is greatest, such as along areas where it is piled up from plowing or from drifting. Gray snow mold becomes active beneath the snow when temperatures are very low but the soil is not frozen. Turf that is affected by gray snow mold has a bleached, grayish, packed-down look. The grass crowns and roots generally survive while the grass blades are killed.

Pink snow mold fungus is found in Midwestern soils and snow cover is not required for it to develop. It is active during the wet, cool weather, that is, during spring and fall. Like gray mold, it usually kills only the blades of grass unless extremely severe infestations occur.
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Thatch
When our lawn started to die we hired a new lawn care service. They said the lawn had a thatch problem. We have always had the lawn fertilized and watered on a regular basis so why is thatch suddenly a problem?
Thatch is a big problem when a lawn receives too much water and fertilizer. Thatch is that layer of partially decomposed stems and roots of grass that lies between the growing grass and the soil surface.  What happened is that the grass roots are growing into this layer and not into the soil, so the grass cannot take up nutrients or water. When this layer gets over one-half inch thick, the grass suffers. It sounds like you have hired the right lawn service. 
You should keep one thing in mind, however. The best time to dethatch is spring or late summer to avoid extra stress to the grass in the heat of summer.

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