Goats on the loose
Watch Goats Beat the World's Worst Weeds!
Some invasive plants can cause problems, but nuking vast stretches of habitat with herbicides and axes does more environmental damage than any plant could hope to achieve. That's why I'm so happy to hear about the goats of Gaithersburg. Goats are the original weed whackers, and professionally managed herds of goats have proven remarkably effective at controlling invasive plants in other parts of the country.
Through July 20, a herd of goats will be making life miserable for the garlic mustard and oriental bittersweet that has overrun the 33-acre wildlife habitat of the Izaak Walton League headquarters, just off Muddy Branch Road next to the National Institute of Standards and Technology in Gaithersburg. The wildlife area is always open to the public, so walk the trail and watch the goats whack them weeds!
Or stop by on Tuesday July 12 at 11 a.m. when the goat herders, weed experts and league members hold a kick-off event designed to promote the idea to other municipalities and private business.
Do Grass Clippings Cause Thatch?
Mike in Ashburn writes: "My father-in-law bags his lawn clippings for the first few mows of the season and doesn't switch over to his mulching mower until the weather really warms up, usually early June. He says that the clippings don't decompose in cool weather and build up thatch. I, on the other hand, set my mower to mulch right away. Which one of us is right?"
You are, Mike. Dedicated mulching mowers pulverize the clippings into a fine powder that gives the lawn a gentle feeding — those clips are 10 percent nitrogen by weight — every time you mow, regardless of the soil temp. It's great for the lawn and the best possible re-use of the clippings. Everyone should use a mulching mower.
He's also wrong about thatch, a layer of dead brown stolons on the surface of the soil. Thatch is not caused by grass clippings, even big ones. Thatch is 100 percent the direct result of lawns being over fed, typically with chemical fertilizers. In fact, the pulverized clippings from a mulching mower will help thatch break down, which means mulched clippings are a cure for thatch, not the cause.
Rolling in the Clover? More Food, Less Water!
Michaela in Columbia, Maryland writes: "For the past six years I have dutifully followed your advice regarding lawn care. I aerate and over seed every fall and spread corn gluten meal every spring. But my lawn is becoming a huge sea of clover! What am I doing wrong?"
Clover in a lawn is a sure sign of overwatering and under-feeding, Michaela.
Many people water their lawns daily to try and keep them green over summer, but this is actually bad for turf grass (and great for clover. The only correct way to water a lawn is to deliver one, during normal weather, or two, during severe hot and dry stretches, long soakings a week. I'm talking several hours long to really saturate the subsoil. Always time your watering to end just as the sun strikes your lawn. When in doubt, like when we've had a fair amount of rain, don't water-- your grass has to be able to dry out between watering sessions.
And if all you're feeding is corn gluten in the spring, your lawn is starving. Don't feed it now-- summer feedings are death to lawn grass. But do plan for a big natural feeding this fall. You can use more corn gluten, about 20 pounds per thousand square feet of turf, a bagged organic lawn fertilizer, or even better, spread an inch of compost overtop and then gently rake it in to feed the lawn and put some life down in that soil.
You Can't Grow a Lawn on Wood Chips
Janet in Bethesda writes: "We just had an old oak tree removed and the trunk ground up. While a considerable amount of the wood chips were hauled away, lots of them are still covering the ground. What is your best advice on growing grass in the tree trunk area?"
Well, first, you have to remove every little bit of that wood chip mess, Janet. If you leave it there — or, God forbid, till it into the soil — it will starve any new plants to death for years to come by absorbing all the available nitrogen.
After the area is clean, have a big load of bulk compost, or a 50-50 mix of compost and screened topsoil, delivered. Level the area well and sow your seed between August 15 and the middle of September, but no earlier.