by Mark Levisay
Most people probably agree that a weed is simply a “plant out of place.” Tall fescue, your typical lawn grass, is certainly a weed in your vegetable garden. A beet showing up in your lettuce bed might be too, but maybe not as onerous! Dandelion flowers are lovely, but nobody seems to like them in the lawn—but the bees certainly appreciate their early flowers.
What makes a weed such a problem?
Many weeds are fast growers, and as such may out-compete the flower and vegetable plants you’re trying to grow. They take valuable nutrients out of the soil to support their own growth, robbing your desired plants of what they need. They may even shade or crowd your seedlings to the point they can’t grow at all. Many weeds excel at growing on poor and compacted soils where other plants can’t thrive, so Imagine how much they like your improved garden soil! Their fast growth and short reproductive cycle (many mature, bloom and set seed in just a few weeks) demand quick action.
Henbit, one of the most pervasive weeds in the garden early in the spring.
What can we do to stop the weeds?
Physically we can just go out and dig or pull them-most easily done when the ground is wet. For centuries, humans cultivated crops with hoes (and sticks before that) to kill weeds while preserving the desired plants. A few more modern ideas:
Use landscape fabric as a barrier to prevent weed seeds from sprouting and growing. It’s even more effective when used with mulch.
Mulch itself helps a lot. It makes the weeds that do appear easier to pull and improves the soil in the long run. Even newspapers can prove effective as a barrier.
Mow the lawn as high as your equipment allows so the grass will shade out weeds.
Plant wide rows of vegetable plants or put flowers in clumps close together to crowd out the weeds.
Chemical weed control
There are two fundamentally different ways to attack weeds with chemicals. One is a pre-emergent product which keeps weed seeds (many are annuals) from germinating. Crab grass preventer for lawns is one example. Applied at this time of year (when the forsythias are blooming) it keeps last year’s crabgrass seeds (and other annual grass seeds) from sprouting. “Preen” is a granulated pre-emergent product you can use in vegetable and flower gardens as long as you are NOT PLANTING SEEDS in those areas. This product works great around perennials, or where you might be planting established seedlings like tomatoes or peppers.
Contact herbicides can themselves be divided into two types. Broad spectrum chemicals like “Roundup” kill everything they’re sprayed on. Roundup (glyphosate is the active ingredient) is absorbed by the plant and disrupts the cycle of photosynthesis. More selective herbicides differentiate between monocots (grass) and dicots (broadleaf plants). These are usually applied to lawns to kill non-grass weeds like dandelions or chickweed. As always, read the label, follow the mixing instructions, and avoid contact as much as possible. Some of these herbicides are very controversial so make informed choices.
If you keep after them, you can get ahead of the weeds. Try to break their flowering and seed distribution cycle and you’ll have less work to do over time!
Have a garden question? Send me an email at marklevisay@gmail.com.