Weed Control 101
Q. Mike: I have at least 10 different weeds in my yard, some of which are extremely difficult to pull out by hand. I also managed to 'get' poison ivy while weeding, even though I wore gloves, so I don't know how it happened. Any ideas on how I can combat these weeds; and what I can do about the poison ivy? I won't use chemicals because of the birds I feed, and the frogs and turtles that pass through the yard.
- ---Memo in Haymarket, VA
So wet the soil well or wait till right after a heavy rain, and pull gently and firmly at the base of each vine with heavy plastic bags covering both of your hands. Fold the bags down to cover the pulled greenery, toss the bags in the trash and repeat with fresh bags if there are more plants to pull. Never re-use a bag, and never-ever-ever use gloves to pull poison ivy, because the allergenic oil gets on the gloves and then gives you a new rash every time you touch those gloves for months to come. (Memo should wash her contaminated gloves well in cold water or just throw them away.) You'll find more detailed poison ivy pulling directions in this previous Question of the Week.
With regular old weeds, choosing the best method of safe and effective control always depends on where the weeds are.
Weeds in lawns, for instance, are best attacked IN-directly, by building up the lawn, because the deep roots of a healthy lawn will crowd out any weed. That means never cutting cool-season grasses lower than three inches; feeding your lawn naturally and at the right time of year; and watering deeply and IN-frequently when we don't get rain (watering every day for short periods of time guarantees maximum weed woes). You'll find more lawn care details in this previous Question of the Week.
For weeds in other areas, I typically recommend non-chemical options like herbicidal soap sprays, flame weeders and high-strength vinegar products; and we will touch on these important tools in a moment.
But several listeners have taken me to task over the years for not recommending hand-pulling as the first option. And ya'll are right! I often fall into the habit of replacing deadly products with similar products that aren't deadly, because I really want our listeners to stop using toxic sprays, and I figure this is the easiest first step. But in doing so, I sometimes fail to mention simple, basic and free options-like hand-pulling, which is the best way to accomplish the chore for those of us who are physically able.
I've been hand-pulling virtually all of my weeds so that I can toss them (with lots of nice garden soil still attached to their deep, nutrient-rich roots) into my compost piles. I especially like the fact that I 'get even' with those wascally weeds when I feed my 'wanted' plants that compost later on! And even though I always warn you folks out there not to try and compost green material alone, that seems much more true of kitchen waste than garden weeds-my unwanted plants are turning into really nice black gold! Must be the warm weather and all that compost-rich soil clinging to their roots.
(But I repeat my kitchen waste warning-a compost bin filled with shredded leaves and kitchen waste will produce beautiful rich compost; a compost bin filled with kitchen waste alone will produce decidedly UNbeautiful, worthless, rotten kitchen waste.)
Anyway, the secret to successful hand-pulling is to thoroughly wet the soil first (or to weed right after a heavy rain). Pulling from dry soil is somewhere between difficult and impossible. You get the entire weed, roots and all, easily when the soil is wet. And pace yourself! I try and limit my 'green manure' harvesting to one hour a day (ideally the coolest part of the day). That way, I get a nice daily workout and stay ahead of those horticultural hellions without exhausting myself.
But sometimes it's still 80 degrees out there at dawn. (Thanks a lot, Al Gore!) And that's when I'll take a break from physicality and use a small propane-powered flame weeder, especially to dehydrate and kill the weeds in my gravel driveway and stamped-concrete patio. My personal choice is BernzOmatic's "Outdoor Torch". Wait for a dry spell, screw a camp-stove sized propane bottle into one end of the long wand, click the igniter, wave the flame over the tops of your weeds, and they will dehydrate and die. Any hardware or home supply store can order one for you, or get it directly from BernzOmatic by calling their toll-free #, 1-800-654-9011 (they don't sell online). A number of other companies offer similar devices.
If you do choose flame, be careful not to set leaves or brush-or yourself-on fire. This shouldn't be a problem on pavers (the leaves and brush, anyway), but once you have one of these things, you are tempted to use it everywhere. So if you wander off with your flamethrower, have a helper handy with a hose.
Herbicidal soap sprays-available from a number of retailers-are another good option. Spray the unwanted plant on a hot, dry day, and the soap will coat and smother it. Like flame, these sprays are safe to use on concrete pavers and the like.
But vinegar products are not. Although they are environmentally safe, these herbicides should never be used on or near concrete or pavers. You can buy commercial vinegar-based products (these typically combine an 8% acidity vinegar with something like clove oil), or make your own. Pour full strength (5%) white vinegar into a spray bottle, add a few drops of dishwashing soap and vegetable oil (one drop each per pint of vinegar; this will help the vinegar stick to the weeds), shake well and spray on a hot and dry day.