The lowdown on crab grass
Mike McGrath, WTOP Garden Editor
Editor's note: Meet Mike Saturday, April 27 at the Community Home Show in Ocean Pines, Md. and Saturday, May 4 at the Prince William County Compost Awareness Day at the Balls Ford Road Yard Waste Compost Facility in Manassas, Va.
Drop those pruners, pal!
Craig from Damascus has a timely question. He writes: "When is the proper time to prune bushes like azaleas, evergreens, Manhattans and Leylands?"
Well Craig, spring blooming shrubs like azaleas and rhododendrons, lilacs and forsythia should only be pruned right after they finish blooming otherwise you risk cutting off next season's flower buds and getting no springtime show.
I was going to say that only Godzilla and Mayor Bloomberg get to prune Manhattan, but finally discovered that Manhattan is also the variety name of an evergreen. Your Leyland is also an evergreen. Evergreens don't need any pruning, but if you feel you must, you can safely trim them lightly and gently from mid-May through mid-June.
Don't cut the tops off of evergreens, and don't prune anything in the Fall.
Springtime is not aeration time
Mike in Springfield writes: "My front yard was just sodded with fescue, but the backyard needs work. A landscaper we contacted thinks we should aerate the whole yard, till the dead spots and then spread seed. But your articles make me think that's not such a good idea."
It's a bad idea in many ways, Mike!
Cool season lawns should never be aerated in the spring. Pulling out all those little plugs to relieve soil compaction stresses the turf in the short run and you never want to do anything to stress a cool season grass with summer heat around the corner. Core aeration should only be done after the summer heat breaks in the early fall, when the grass will be entering its strongest phase and can recover quickly. The opposite is true for warm season grasses like zoysia and Bermuda. They should be aerated in the spring and not the fall.
And grass seed sown in spring rarely-to-never produces well.
So either have sod installed in the backyard this spring or just cut what's there at three inches over the summer and then take stock mid-August. If the lawn looks fairly decent at that point, aerate and overseed it. If it looks nasty, till it all up and reseed. Seed sown between August 15 and the end of September produces an excellent turf.
Weed killers don't kill lawn weeds
Larry in Vienna writes: "My yard is shaded by some fairly tall trees and has a weed problem. Two lawn care companies said I have Japanese Stiltgrass; a third said I also have Wild Violets and Wild Mustard. A very reputable lawn and garden center nearby recommended "Speedzone" and "Bayer Advanced," which I have applied three times each a year for the past four years. The weeds continued to come back, so I had a lawn care company Roundup the whole yard, sod the front and reseed the back. Since then I've continually applied the herbicides, but the weeds keep coming back. I really need your help and will take any suggestions you might have."
Larry did not appreciate my first suggestion, which was to sell his sprayers and make large donations to the Bird and Frog Widows and Orphans Fund. Then, after a few emails back and forth, he reluctantly agreed to try "something safe for the environment if it works."
Larry, your half decade of toxins hasn't worked! Take care of your lawn correctly for a single season and you'll have many fewer weeds and a much less silent spring.
The golden rules of lawn care
The dirty little secret of lawn care is that chemical herbicides are a great threat to human and animal life, but rarely-to-never control weeds. The best way to fight lawn weeds is simply to treat your lawn correctly.
- Never cutting your grass lower than 3 inches for a lawn in sun and 3.5
inches for lawns in shade. Scalp the grass and weeds will win.
- Returning the nitrogen-rich clippings to the turf. Removing the clippings
starves your lawn of its most natural nutrient. Returning the clippings feeds your
lawn naturally every time you mow. And if you use heavy chemical herbicides, you
must return your clippings to the turf. Those clippings are toxic to any other
plant than lawn grass even if they're completely composted.
- Watering deeply but infrequently. Watering more often than once or twice a
week encourages puny grass roots and weed invasion. Daily watering begs weeds to
- Never feeding a cool season lawn like bluegrass or fescue in the summer, only in the spring and fall. Summer feedings burn up cool season lawns.
Proper care for a single season will eliminate more weeds than a decade of chemical sprays.
You can weed and feed, but you can't weed and seed
Mark in Warrenton writes: "I'm about to put crabgrass killer on the lawn - I believe this is the appropriate time of year - as the red buds and forsythia are blooming. Can I subsequently put down grass seed?"
No, Mark you can't. Whether it's a nasty chemical weed and feed or non-toxic corn gluten meal, all pre-emergent herbicides work by preventing seeds from successfully germinating and they don't discriminate between good seed and bad seed. Grass seed sown in spring rarely-to-never works well anyway, so get that corn gluten down ASAP. The soil temperature has really soared in the past week and crabgrass seed is now beginning to germinate. Save the grass seed for late summer, when it always works well.
Follow @WTOPLiving on Twitter.
© 2013 WTOP. All Rights Reserved.