If you were to track every hour spent in your garden, you
would probably find that you do an inordinate amount of weeding. And while the
first few weeks of tearing up these intruders can prove mildly satisfying, the
chore soon wears thin. Even more maddening—you are just six simple strategies
away from your garden not needing weeds anymore.
What’s that? A garden needs weeds? Weeds are nature’s healing
remedy for sites that are in a wounded, plantless state, but weeds and
gardeners have different ideas of what makes for a good recovery. Armed with a
better understanding of weeds and the strategies outlined here, you can win
every future skirmish, giving you more time to enjoy your well-groomed garden.
1. Let sleeping weeds
lie
Kill weeds at their roots but leave the soil—and
dormant weed seeds—largely undisturbed.
Every square inch of your garden contains weed seeds, but
only those in the top inch or two of soil get enough light to trigger germination.
Digging and cultivating brings hidden weed seeds to the surface, so assume weed
seeds are there ready to erupt, like ants from an upset anthill, every time you
open a patch of ground. Dig only when you need to and immediately salve the
disturbed spot with plants or mulch. In lawns, minimize soil disturbance by
using a sharp knife with a narrow blade to slice through the roots of
dandelions and other lawn weeds to sever their feed source rather than digging
them out. Keep in mind that weed seeds can remain dormant for a long, long
time.
2. Mulch, mulch,
mulch
Don’t give weeds the chance to see the light. Whether you
choose wood chips, bark nuggets, straw, or even pine needles, keep the mulch
coming to smother out weeds.
Mulch benefits plants by keeping the soil cool and moist and
depriving weeds of light. Organic mulches, in particular, can actually host
crickets and carabid beetles, which seek out and devour thousands of weed
seeds.
Some light passes through chunky mulches, and often you will
discover—too late—that the mulch you used was laced with weed seeds. It’s
important to replenish the mulch as needed to keep it about 2 inches deep (more
than 3 inches deep can deprive soil of oxygen). In any case, you can set weeds
way back by covering the soil’s surface with a light-blocking sheet of
cardboard, newspaper, or biodegradable fabric and then spreading prettier
mulch over it.
If you choose to use this method on seldom-dug areas, such
as the root zones of shrubs and trees, opt for tough landscape fabric for the
light-blocking bottom sheet. There is a catch, however: As soon as enough
organic matter accumulates on the landscape fabric, weed seeds dropped by birds
or carried in on the wind will start to grow. For the bottom layer of fabric to
be effective, these must be pulled before they sink their roots through and
into the ground.
Monday: Kill weeds. Tuesday: Kill weeds...
If you’re a new gardener—or you’re working in a wild and
weedy space—the first season will likely be a rough one. Commit (and stick) to
a weeding schedule, and don’t take on more space than you can manage. If you
have more weeds than you can handle, keep weedy areas mowed until you’re ready
to conquer them.
3. Weed when the weeding’s good
Young weeds go down much easier than older ones, so make the
most of good weeding conditions.
The old saying “Pull when wet; hoe when dry” is wise advice
when facing down weeds. After a drenching rain, stage a rewarding weeding
session by equipping yourself with gloves, a sitting pad, and a trug or tarp
for collecting the corpses. As you head out the door, slip an old table fork
into your back pocket because there’s nothing better for twisting out tendrils
of henbit or chickweed. When going after bigger thugs, use a fishtail weeder to
pry up taprooted weeds, like dandelion or dock.
Under dry
conditions, weeds sliced off just below the soil line promptly shrivel up and
die, especially if your hoe has a sharp edge. In mulched beds, use an
old steak knife to sever weeds from their roots, then patch any open spaces
left in the mulch.
Heat is the key to composting weeds
Few experiences compare to the joy of watching weeds shrivel
in the sun after a morning weeding session, but then what should you do with
them? Their best resting place, of course, is a compost pile or bin, which is
the end of the story if the weeds going in are free of seeds. In reality,
however, a good half of the weeds you pull probably hold seeds. Separating the
seedies from other weedies is impractical, so weed seeds in compost are
customarily killed by raising the temperature in the heap.
Keep it hot. Running a hot heap calls for precise mixing and
remixing of materials. Rather than struggle to heat up a heap that wants to run
cold, I suggest waiting until a weedy heap reaches a nearly rotted state to set
things right. From there, you can solarize small batches of moist compost in
black plastic nursery liners that are enclosed in clear plastic bags and placed
in the sun for two to three days.
Now you’re cooking. Easier than solarizing, plug in an old
Crock-Pot outdoors, turn it to its lowest setting, and warm batches of compost
while you sleep (three hours at 160°F kills most weed seeds).
Heat treating weedy compost destroys many of the microscopic
life-forms that give compost its punch, so it’s a good idea to reprocess cooked
compost for two to three weeks before using it in the garden. Place it in a
plastic storage bin with a handful of earthworms borrowed from your garden and
it will soon be laced with humic acids and other plant-pleasing compounds.
4. Lop off their
heads
Chopping off weed heads feels good and you’ll reap
short- and long-term benefits.
When you can’t remove weeds, the next best thing is to chop
off their heads. With annual weeds, deadheading buys you a few weeks of time
before the weed “seed rain” begins. Cutting back the tops of perennial weeds,
like bindweed, reduces reseeding and forces them to use up food reserves and
exhaust their supply of root buds, thus limiting their spread.
You will need pruning loppers to take down towers of ragweed
or poke, or you can step up to a string trimmer equipped with a blade
attachment to cut prickly thistles or brambles down to nubs. No matter which
method you choose, chopping down weeds before they go to seed will help keep
them from spreading.
5. Mind the gaps
between plants
Tightly planted beds leave no room for unwanted
visitors.
Close plant spacing chokes out emerging weeds by shading the
soil between plants. You can prevent weed-friendly gaps from the get-go by
designing with mass plantings or in drifts of closely spaced plants rather than
with polka dots of widely scattered ones. You can usually shave off about 25
percent from the recommended spacing.
Most
spacing recommendations, however, are based on the assumption that adjoining
plants will barely touch when they reach mature size, so stick with the
guidelines when working with plants that are prone to foliar diseases, such as
bee balms (Monarda didyma and cvs., USDA Hardiness Zones 4–9) and phloxes (Phlox
paniculata and cvs., Zones 4–8).
6. Water the plants
you want, not the weeds you’ve got
Drip irrigation is the way to go for a quick way to water
your plants and not your weeds. Watering by hand works, too, but it’s often
tedious.
Put drought on your side by depriving weeds of water.
Placing drip or soaker hoses beneath mulch efficiently irrigates plants while
leaving nearby weeds thirsty. In most climates, depriving weeds of water
reduces weed-seed germination by 50 to 70 percent. Watch out, though, for the
appearance of deeply rooted perennial weeds, such as bindweed and nutsedge, in
areas that are kept moist. They can take off in a flash when given the benefits
of drip irrigation.
Beyond
these strategies, enriching your soil with organic matter every chance you get
can move your garden along down the weed-free path. Soil scientists
aren’t sure how it works, but fewer weed seeds germinate in soil that contains
fresh infusions of good compost or organic matter. One theory makes elegantly
simple sense: When soil is healthy and well fed, weed seeds sense that they are
out of a job and are less likely to appear.