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What not to plant in the heat and how to handle brown spots

Friday - 7/19/2013, 10:52am  ET

Watering in the middle of the day is waste of time

WTOP Garden Editor Mike McGrath


WASHINGTON - Jim in Spotsylvania writes: "I have tall fescue that I fertilize three times every fall with a Scott's product -- September, October and December. I also fertilize once in the early spring. The lawn starts out looking gorgeous until the temps rise in summer, then it develops big patches of brown. We've had copious rain, so I don't think its lack of water. Is this 'summer stress' or something else?"

If you had fed it this summer, it would have been straight burn-out, Jim. Cool-season grasses like fescue are, as you note, already heat stressed, and summer fertilization generally pushes them over into the Land of Death.

But because you fed so much last fall/winter and temps have recently been hot and the air hideously humid, it's almost certainly 'brown patch.' This fungal disease devastates fescue lawns in our region that have been overfed with cheap, quick- release chemical fertilizers (or even slow release chemical fertilizers if you really hammer the poor turf, which you have done). The over-fed turf generally looks much too lush in the spring, and then succumbs to patchiness when D.C.'s legendary summer heat and humidity push it over the brink.

Three feedings in the fall is two too many, and December is way too late to be feeding anything. For now, just let the lawn try and recover naturally. Then drop down to one feeding in September and you should be fine, especially if you're willing to get your lawn off drugs and go with an organic lawn food.

Door-to-door pesticide sprayers are the real pests

Tim from Springfield writes: "This past week I have been approached by two different door-to-door companies offering pesticide services. When I expressed concern about my two dogs, the salesmen said that the pesticides they use aren't harmful. My wife hates seeing spiders and crickets in the house, but based on years of listening to your radio spots, I think of spiders as beneficial insects. What do you recommend?"

I recommend that you never buy anything from a stranger at the door, especially someone looking for a reason to enter your home -- that's just begging to be robbed. And I recommend that you never have pesticides sprayed inside your home, where you'd then be inhaling the poisons 24/7. (And poisons they are, no matter the pitch.)

Neither of your so-called 'pests' is harmful. Cave or Camel Crickets are spooky looking but do no harm. And you are correct that spiders are tremendously beneficial. They eat lots of true pests, and despite their lurid urban legends, pose no threat to people. (No, your neighbor/friend/cousin/co-worker was not bitten by a brown recluse spider, no matter how much they wish and/or insist they were…)

If you feel you must do something to keep the peace at home, buy sticky traps and place them where you see the cricket. They'll get rid of your 'problems' without any poisons.

But be prepared to see a huge increase in true indoor pests, including ants, flies and roaches, if you wipe out your spiders. You wouldn't be seeing lots of spiders if there weren't lots of little things for them to eat.

Horse manure = 20-foot-high plants with two tomatoes

Jasper, in the Hampton Oaks Community down in Stafford, writes: "I have beautiful plants -- tomatoes, string beans and lima beans-that are very tall and healthy, but producing very few blooms and little fruit. My garden bed is amended with cow and horse manure. Do you have any suggestions?"

Yes, Jasper. I suggest you go back in time and either ditch the manure or use it to grow a nitrogen-craving food like sweet corn instead. Horse manure is very high in nitrogen, a nutrient that grows big plants but that also inhibits flowering and fruiting. People who try to grow fruiting crops (tomatoes, peppers, cukes, squash and beans) with a lot of horse manure get huge plants with very little to eat.

Run out and get a liquid (not granular -- you need something that will be active fast) organic fertilizer that contains a lot of phosphorus. That's the middle number on the label. All fertilizers have three numbers on the label. You want a low first number and a relatively high middle one, like a 2-6-4 or something. (Don't use worthless junk like 10-10-10 or anything with numbers higher than 10.)

With any luck, it'll get the plants fruiting by next month. And next year, no manure.

Don't plant witch hazel -- or anything else -- right now

Dave in Vienna writes: "I have a 3-foot-tall witch hazel in a large container that I plan to plant soon. A number of its leaves are now perforated with holes. From my 'net research, I'm guessing they're caused by a witch hazel-specific weevil. Does this sound likely to you? Whatever the cause, what do you suggest?"

It could be your witchy weevil, Dave. Or, it could be Japanese beetles, flea beetles or any number of pests. For now, just hose the plant down well with sharp streams of water, wipe down the outside and rim of the pot, move the container to a spot that gets dappled shape (not direct sun) and place a sheer curtain or row cover (like "Reemay") overtop to prevent further damage.

Most important, wait until September to plant it in its permanent location. Plants installed at the height of the summer have a very low survival rate.

Ponds will parade for a good cause next weekend!

Last week's brutal weather had a lot of us thinking about water. Water to swim in, water to drink…and who didn't break out into a smile when they got near a nice display fountain on a scorching day?

Well, next weekend (July 27 and July 28) you can cozy up to a lot of water when Premier Ponds of Burtonsville hosts its 6th annual Parade of Ponds to benefit the Shepherd's Table in Silver Spring. This year's event will feature over 20 custom-built ponds, waterfalls, streams and water gardens -- mostly in or around the Burtonsville area of Maryland.

The tour is free, but donations of $20 are suggested, and those donations will benefit the Shepherd's Table, a nonprofit that provides essential services to the homeless.

Find more info and a tentative list of tour locations here.

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