Yes, this miserable heat wave is just as stressful to local lawns as it is to us.
That’s because most of our lawns are composed of bluegrass, rye and/or fescue. These “cool-season grasses” are originally from parts of Europe where summers are much more mild. To help them cope with this ridiculous heat:
- Most importantly, do not feed or apply any kind of weed treatment to your lawn for the next six weeks or so. Fertilizers and herbicides will just burn the turf up.
- Do not cut the grass lower than 3 inches. It needs that much height to shade the soil to try and keep its roots cool.
- Don’t cut your lawn at all during a dry heat wave. Wait until the weather breaks and/or rain is predicted after the cut.
- You can certainly water your lawn — and you should if there are five days without a solid inch of rain or water from irrigation.
- But only water it deeply — for several hours at a pop. Short waterings that don’t really saturate the soil are useless. In fact, short and/or frequent watering encourages the roots of your lawn to remain too short to sustain the turf during a heat wave.
- Water only in the early morning when the grass is most receptive.
- Don’t water during the heat of the day — when the grass blades and roots are closed up tight to retain what moisture they already have — or in the evening, which can cause disease to spread and prosper.
- Don’t water more often than twice a week.
- And don’t freak out if your lawn turns a little brown when the thermometer reads three digits. Just water it deeply, don’t feed, treat or cut it, and it’ll green right back up when the weather breaks.
Check tomato plants for horrible hornworms!
So I went out yesterday and saw that deer had apparently gotten to one of the tomato plants I have been growing in a huge multi-plant “garden tower” container thing on my patio. The tower is close to 5 feet tall, so I’m just letting the vines drape down over the sides — where they’re exposed to hungry deer (unlike my in-ground tomatoes, which are securely caged).
The damage sure looked deer distinctive — whole branches bitten off cleanly. Then I saw what looked like a green bulge on one of the lower branches and pulled off a huge, fat tomato hornworm. These are the biggest, hungriest caterpillars in our area — and so exactly the color of tomato branches and leaves that they’re almost invisible. So if you see missing branches and half-eaten fruits, inspect your plants carefully!
Hornworm hunting
The tomato hornworm is the largest caterpillar in our region. But despite their massive size and the amount of damage they can cause, their green color is so perfectly matched to that of the tomato plant that they’re difficult to see—even if you’re looking right at them.
Instead, look for branches with large sections bitten off cleanly at the end, then trace that branch back and look for a green bulge blending in perfectly a little lower down or off to the side. Or look underneath the damage for another clue: Their massive telltale droppings of frass — a $20 word for bug poop.
A careful inspection could well save your harvest. These huge caterpillars are at their most active right now and it only takes a few of them to defoliate an entire tomato plant.
Don’t squish hornworms with white spines on their back
Yes, if you find a big green caterpillar eating your tomato plants, you can—and should—pull it off and squish it. (Unless you have chickens; they would greatly enjoy being tossed some of those big green treats.)
But don’t squish if that caterpillar has what look like white spines down its back. Those ‘spines’ are the egg cases of an almost microscopic wasp that is the hornworm’s most fearsome foe.
A hornworm with visible cocoons has already been weakened greatly and won’t be able to do much more eating—so just leave it be. The baby wasps that hatch out of those cocoons will finish the job by feeding on the insides of your tomato fiend; and then they’ll fly off in search of more prey.
These parasitic wasps may only be the size of the period at the end of this sentence, but they’re a tomato’s grower’s biggest friend.
Don’t feed the birds — water them!
This heat wave is as tough on the local bird population as it is on us. Just like us, those birds need lots of fresh water, which is very scarce in the wild at this time of year.
So bring on the birdbaths—the more the better! Keep them filled with clean fresh water and birds will—ahem—flock to your landscape.
Bonus: Position those birdbaths near plants with pest problems and the birds will eat some of your bad bugs and beetles on their way in and out.
But don’t fill seed feeders at this time of year. The Humane Society notes that the baby birds that have recently hatched will do much better in the long term if they learn to find their first food in the wild, where seeds and insects are abundant at this time of year.
It’s fine to feed birds in the winter, but right now what they need is water—fresh, clean and lots of it.
Mike McGrath was Editor-in-Chief of ORGANIC GARDENING magazine from 1990 through 1997. He has been the host of the nationally syndicated Public Radio show “You Bet Your Garden” since 1998 and Garden Editor for WTOP since 1999. Send him your garden or pest control questions at MikeMcG@PTD.net.
