Wild Garlic Woes

Ugly clumps of wild garlic leaves are marring the dormant zoysia grass around my home garden and the mixed grasses in my pasture. Wild garlic is Allium vineale, a member of the lily family. The strong oniony stench of bruised leaves is anything but lily-like. Mature leaves are 6 to 12 inches in length. Wild onion, Allium canadense, is similar in appearance but wild garlic has round, hollow stems while wild onion has flat leaves that are not hollow. Both these plants are winter perennials that emerge in late fall, grow throughout winter and early spring, then go dormant.

Wild garlic has a teardrop-shaped bulb with a fibrous mat of roots. If allowed to mature, stems will form flowers or bulblets at the top of the stem, resembling chives. Flowers may be pink, white, or lavender. If you decide to mow over the clump, do so before the flowers/bulblets have formed or you risk spreading the misery as seeds are discharged across your lawn.

Wild garlic will grow in any type of soil and any pH. It is both drought tolerant and bog tolerant. It prefers full sun but tolerates shade. It tolerates frosts and hard freezes.

Both wild garlic and wild onion resist eradication attempts. Years ago, I decided to ignore the clumps of wild garlic in my lawn since their appearance was short lived. Mistake! While the top growth is dormant, they are reproducing underground via bulb offsets. Without treatment, they come back larger and stronger from year to year.

“Treatment” can be chemical or manual. I always try to use a non-chemical approach as my first line of defense. Removal is a painstaking chore, best done after a soaking rain has softened the soil. In past years, I used an asparagus/knife weeder which resembles a long-handled screwdriver with a forked tip. My new tool of choice is a hori-hori. It has a wider forked blade that is serrated on one side with a sharp edge on the other. With the hori-hori, I am able to saw through sod and lift the entire clump of garlic bulbs, carefully ferret out the individual bulbs, then replace the lifted sod. The bulbs are further below soil surface than one might expect, so be prepared to dig several inches deep. Use a foam kneeling pad to save wear and tear on the body. Use disposable gloves to avoid stinky garlic hands.

If you choose to go the chemical route (and believe me, I’ve been there!), repeat applications of a nutsedge killer may be effective. In areas outside the lawn, a total vegetation, non-selective killer may be used. Because leaves are waxy, use a surfactant (a soluble product that makes the chemical spray adhere) to ensure lasting contact. Clemson University has an information sheet on best practices. Click HERE to read their information bulletin. There is NO effective pre-emergent herbicide.

While my war against wild garlic is purely for aesthetic reasons, farmers have a more serious concern. Cattle that eat wild garlic will produce garlic-flavored milk (yuck!) and poor-flavored meat. If it is harvested along with cereal grains, wild garlic causes an off flavor and even makes machinery gunk up. Farmers usually battle wild garlic with deep plowing in the fall, burying bulbs so deep underground that they cannot survive. Alternatively, or in addition to deep fall tillage, tilling can be done in the spring while the plants are small – one or two leaves. Simple mowing may weaken the plant, but it appears that frequent decapitation forces the underground bulb to become larger and larger. This is why I recommend hand digging with a tool rather than trying to pull them out. A broken stem leaves the enemy underground, gathering energy to rise again.

Teardrop shaped bulbs

Favorite removal tool

Infestation in pasture

The Purple Haze of Lamium

The “purple haze” across lawns and roadsides right now is unrelated to Jimi Hendrix. Instead, it is either Purple Deadnettle or Henbit or both. These weeds are common in the southeast, and can be found growing together. They spread readily and plague homeowners who want a pristine lawn. As a child, I loved the purple flowers with tiny freckles, and gathered many a tiny bouquet as a gift to my tolerant mother.  

A close look reveals the differences between the two. Purple Deadnettle (Lamium purpureum) has heart-shaped leaves, slightly hairy, that attach to the stem with a stalk. The topmost leaves have a purple cast.  Henbit (Lamium amplexicaule) has rounded leaves with scalloped edges that wrap around the stem. Leaves are uniformly green, and attach directly to the stem without a stalk. Stems are square for both, indicating they are members of the mint family. 

These two weeds are not native, but a Eurasian import that has made itself right at home here in the US. While I pull them from my flower beds and borders, I leave those in lawn areas alone.  Deadnettle prefers more sun than Henbit, which prefers shade to partial shade. They appear in all soil types.

Deadnettle and Henbit are reported to be edible. (In this case “edible” means non-toxic and does not equate to “palatable.”) Chickens enjoy eating both flowers and foliage. The blooms provide nectar to honeybees when few other flowers are available, and are also popular with hummingbirds, although peak Henbit season is past when our first hummingbirds appear here in upstate South Carolina. Both plants work well to control erosion (yay!) but set thousands of seeds, all of which seem to germinate (boo!). They can overtake a lawn. 

Both prefer cool temperatures of late winter and early spring, and will gradually fade away once weather is consistently warm. Both plants are annual, so don’t waste time and money applying herbicides.  If you don’t want them in your garden next year, apply anti-emergents in late summer or early fall when dormant seeds are starting to germinate. If you simply must rid yourself of these plants, use an herbicide labeled for broad-leaf weeds and follow the application instructions exactly.

Henbit

Purple Deadnettle

Weed of the Week: Bittercress

While most other plants are just awakening from winter hibernation, Bittercress (Cardamine hirsuta) is actively growing and blooming.  It is an annual weed in the mustard family. It reseeds itself so rapidly that it appears to be perennial. The plant forms a basal rosette of lobed leaves and sends up a wiry stalk. The 4-petal white flowers have a lavender tint near the base. The flowers can mature and set seed in less than a week. Once a few plants have seeded, it is almost impossible to eradicate from the lawn or flower beds.

Pulling the weeds while they are small, before they set seed, is the best way to control this invasive demon. They are easy to remove when soil is damp. If you allow them to seed, you will need to employ both pre-emergent and post-emergent herbicides (look for product that controls broadleaf weeds) to tame it.

Even a tiny plant can bloom. See the photo below, with a house key to show size of the blooming plant. The seed pods, called siliques, look like purple toothpicks. The pods will explode at the slightest touch, throwing seed up to 15 feet away from the mother plant. One of its common names is Shotweed. There is a term for this ballistic seed distribution system: ballochory. Touch-me-nots (Impatiens balsamina) also throw their seeds around this way.

In a Master Gardener class I attended some years ago, the instructor showed a photograph of a nursery in which one Bittercress was left alone for nine weeks. It went from a single plant to an entire village. That one plant spread its progeny to the surrounding twenty-four flats of plants — in just nine weeks!

Bittercress leaves are edible. I’m told they taste like arugula. They do support several varieties of butterflies and one obscure bee, but they are also favored by aphids. In the Mary Snoddy garden, this means “Off with their heads!”

Weed early and weed often.

A single, tiny bloom produces a bazillion seeds, all of which will germinate.