Summer is coming and many of our plants are bursting into flower. But while we celebrate, there’s another less attractive family of plants springing into life as well. These are the dark cousins of our ornamentals: the perennial and annual weeds. The bane of all gardeners, they stubbornly return each year, unfazed by our attempts to remove them.
THE SHADOWY WORLD OF WEEDS
I started delving into the shadowy world of weeds a few years ago when a member of my garden club gave us an odd assignment. She handed each of us a sheet of paper on which were illustrated a dozen garden-variety weeds. Next, she asked us to “locate” them in her garden. Needless to say, we pulled a lot of weeds that day. And I wasn’t thrilled.
However, the experience peaked my interest in this unwelcome form of vegetation.
Weeds compete with other garden plants for water, sunlight and nutrients, often in very aggressive ways. In Maryland, creeping Charlie is one such example. It spreads rapidly by surface runners, quickly carpeting the garden with its fan shaped leaves. (Although it comes up easily in mats, making its removal very satisfying.)
Other weeds like crabgrass, or worse, hairy bittercress (that spits up tiny seeds if you touch it), are harder to eradicate and decidedly much less satisfying to remove.
Eliminating weeds is not only essential to the health of your lawn, but also to your landscape. However, before you start pulling, it’s important to know what you’re dealing with.
WEED ID BASICS: IS IT ANNUAL OR PERENNIAL?
Weeds, just like ornamental plants, are classified by their life spans. They can be annual (growing from seeds spread the previous year), biennial (completing their vegetative growth in the first season and flowering in the second) or perennial (springing up from established roots that survived the winter.) Knowing the difference is important when it comes to eradicating them.
Why? Because herbicides are generally targeted to annual species, which makes perennial and biennial weeds harder to kill. Perennial weeds, in fact, can easily regrow from seemingly dormant stolons, rhizomes, tubers and of seeds. This means they’ll likely be back year after year.
Unlike our finicky ornamentals, weeds can grow anywhere
To help make sense of it all, I’ve been compiling a list of the weeds that show up each year in my garden. It has helped me get to know the different species and understand when and why they appear. Somehow just knowing the names of what I’m removing has made the whole process a bit more satisfying.
Here are the top ten weeds I’ll be pulling this season
Smooth green, finger-like leaves of crabgrass
Long considered a major problem weed in North America, crabgrass can produce up to 150,000 seeds per season all of which germinate in late spring and early summer. An annual grass, it can be distinguished by its slender, finger-like leaves that spread by side shoots from a central hub. Crabgrass grows to form larger and larger clumps over time in star-shaped patterns. Eventually, it becomes a dense mat that smothers the lawn and other weeds.
Interestingly, crabgrass is considered a symptom (and not the cause) of poor lawn health as it thrives in sparse grass that is under watered and not well fed. Experts say that improving the health of your lawn can help reduce crabgrass. Click here for Maryland turf expert Chuck Schuster’s tips on how to build a healthy lawn.
Goosegrass is one of the hardest to remove
Also known as silver crabgrass, goosegrass is a prostrate, bunching grass that spreads by seed and usually emerges a few weeks after its smooth green cousin. It has dark green, thick, flattened leaves and whitish stems that radiate from a central point (which makes it easy to identify.) Small, flattened flowers emerge on stiff spikes from July to September. Unlike crabgrass, goosegrass is very difficult to remove and its seeds spread easily by wind.
Hairy bittercress spits its seeds when you pull it
A member of the mustard family, hairy bittercress has heart-shaped leaves with scalloped margins that grow from a basal rosette. The largest leaves are at the base of the plants. The weed produces tiny white flowers from spring to fall and spits its dried seeds into the air when disturbed. If you can dodge the seeds, hair bittercress is actually easy to pull from wet soil, roots and all. Just give it a good yank on the stalk.
The candle-like inflorescences of broadleaf plantain
Broadleaf plantain has large, oval-shaped leaves that grow in a ground-hugging rosette. The leaves are attached to thick green stems that resemble celery when shredded. Long slender spikes of inconspicuous tiny green flowers spring from the base of the weed from April to September. Broadleaf plantain is actually edible (as are many weeds) and is chock full of iron, minerals and vitamins. The smallest leaves (harvested in the spring) are the tastiest, imparting an asparagus-like flavor. Fresh leaves can also be crushed to treat burns, insect bites and wounds.
Bindweed is a member of the morning glory family
This perennial weed has a spade-shaped leaf with rounded tip and two pointed lobes at the base. Erect seedlings spring from underground stems that can grow to several feet long, causing the plant to bend over and begin its vine-like growth. Whitish/pink, trumpet-shaped flowers, which close each afternoon and reopen the following day, bloom from April to October. Bindweed spreads from both underground horizontal stems and seed and is considered one of the most troublesome weeds in the U.S.
The clear blue flowers of chicory
Of Mediterranean origin, chicory was grown for centuries as a salad green before it started showing up all over our lawns and roads. It has one of the truest blue flowers around. The hardy perennial grows from a deep taproot that forms a prostrate rosette of hairy leaves. From June to September, clusters of daisy-like flowers appear on stiff hairy stalks, opening early in the morning and closing about 5 hours later. In addition to the many medicinal uses for chicory, the weed’s long taproot can serve as a coffee substitute when dried.
Delicate brown flower of yellow nutsedge
Native to North America and parts of Eurasia, yellow nutsedge is a grass-like perennial with shiny yellowish-green leaves and golden brown flower heads. The plant spreads by producing tubers from a complex shallow root system. It can grow in just about any soil or surface, including your driveway.
Mat-forming mouse-ear chickweed
Mouse-ear chickweed is a low-growing, mat-forming perennial with oval, dark grey-green leaves. The leaves are attached directly to the stem, which can be green or purple. Tiny clusters of white, star-like flowers bloom on erect 4″ stems throughout the summer. Mouse-ear chickweed forms dense mats with trailing stems.
Easy-to-pull Creeping Charlie has violet flowers
Creeping Charlie, also known as Creeping Jenny or ground ivy, lives up to its name; it creeps. It has small, fan-shaped leaves with round-toothed edges, which emit a minty scent when crushed. Tiny blue-violet flowers appear in the spring, which look quite pretty wrapped around other garden perennials. Don’t let it get out of control, though, Creeping Charlie spreads rapidly to form dense mats, setting down roots all along its stems.
MOCK STRAWBERRY (the prettiest of weeds)
Tiny fruits of mock strawberry make it easy to distinguish
Resembling common strawberry, mock Strawberry is a ground-hugging plant that spreads by hairy runners and forms crowns at nodes. Its leaves are toothed and have dense hairs on the upper surface. Yellow flowers with five petals appear from April-June followed by tiny red strawberries. The fruits are edible, but have very little taste. The plant has been used for centuries for medicinal purposes, including as a fever reducer and antiseptic.
A portion of my lawn (below) is currently being invaded by mock strawberry.
Of course, there are so many other weeds to pull, including clover, ragweed and dandelions, to name just a few. This list is by no means exhaustive. NOTE: Remember to pull weeds when the ground is wet- it makes it a lot easier and you’re more likely to get the entire plant instead of leaving part of it in the ground. Click here for a great tutorial on fast and easy ways to remove weeds from the garden.