Green sticky weeds with yellow seeds

Weedy Wednesday – Goosegrass (Cleavers)

This week’s plant in our Wednesday Weed series is Goosegrass, also known as Cleavers, or Sticky Willy.

In this weekly series, we take a quick look at common garden weeds. How they grow, what benefits they bring to the garden, and how to manage them. Organic growers recognise the importance of these native plants. Insects and birds need the flowers and seeds – and gardeners, cooks and herbalists can harvest some nutrient rich foliage.

For more detailed information on over 100 individual weeds, go to the superbly researched Weeds List, and here for how to manage them.

Goosegrass, Cleavers or Sticky Willy Galium aparine

What: This annual weed is a rapid grower, and can form dense patches, pulling down surrounding plants. It is the small hooked hairs growing out of the stems and leaves which latch on, giving the name Sticky Grass or Sticky Willy. Geese particularly enjoy eating it – hence the nickname Goosegrass!

Habit: This plant can survive in heavy, waterlogged as well as dry soil. It has tiny, star-shaped, greenish-white flowers, from June to August. These develop into globular fruits, or burrs, which are also covered with hooked hairs which cling to clothes and animal fur, aiding seed dispersal. Seedlings that emerge in the autumn reach a height of 10-20 cm at which stage they overwinter. They are not damaged by frost. Stem growth begins again in April, rapidly increasing as days lengthen.

Benefits: Cleaver seeds can be roasted and are claimed to be an excellent coffee substitute (however they do have a laxative and emetic effect.) The dried matt of foliage was once used to stuff mattresses, whereas the roots create a permanent red dye.

Control: As this is an annual weed, hand pulling and hoeing will all help – especially before flowering and seed setting. Alternatively a thick mulch in early spring or late autumn will reduce seedlings’ ability to emerge.

For further information on this and other weeds, go to the Weeds List, and here for how to manage them.

How to Get Rid of Sticky Willy

Perhaps best known as Sticky Willy, Galium aparine – USDA growing zones 3 to 7 – is an annual plant, largely considered to be a weed. With some basic steps, however, the savvy gardener can effectively remove it from his or her yard. Also known as Goosegrass, Coachweed, Catchweed and Cleavers, it can cause some serious problems for both gardeners and farmers.

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Why Get Rid of Sticky Willy?

The sap of the plant can cause severe skin irritation in people who are sensitive to it. If left unchecked, the plant can also severely hinder other plants’ ability to grow. If left unchecked in agricultural operations, the plants can reduce crop yield in some species by between 30 and 60 percent.

The seeds and foliage of Sticky Willy can contaminate the wool and fur of some livestock raised for the production of clothing. If animals consume it, it can inflame their digestive tracts. Its seeds can get stuck in the fur of animals and is very difficult to remove. It can also carry with it different diseases and pests.

Identifying Sticky Willy by Its Small Spines

Sticky Willy is quite easy to identify, thanks to the downward-pointing brown prickles on its leaves – which appear in groups of between six and eight – and stems. Its oblong-shaped eggs have slightly notched tips. Its seed leaves, or cotyledons, are smooth, however. If allowed to mature, Sticky Willy can grow to be 40 inches tall. Large groups of the plants often spread in dense mats over the ground, made all the more dense by their spines. Their flowers are four-parted and often white or greenish-white.

The weed can be found around the world. Most often, Sticky Willy grows in moist and shady areas such as areas filled with waste, on roadsides and in gardens. The species can also affect the growing of hay, rapeseed, sugar beets and various cereals.

Removing Sticky Willy Is Harder Than You Think

Getting rid of a Sticky Willy plant is easy enough; in fact, it’s just a matter of pulling it from the ground. However, each plant can have between 300 and 400 seeds, which spread readily and can lie dormant in soil for six years.

The best way to remove the plants for good is to get them out of the soil before the plants flower and develop their seeds — ideally in the early spring. This can be done using a hoe or another tool that gets to the roots, or by hand. As the plant’s sap is irritating, wearing gloves is an important step if you choose the latter option. If the plant has already flowered, attempting to remove it will only spread the seeds.

Applying a heavy layer of organic mulch or using plastic mulch can also prevent the seeds from reaching the soil or getting enough light to grow.

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Gardeners looking to avoid Sticky Willy near their homes should be sure to brush down their clothing and pets after walking in areas where the weed is commonly found, or after exposure. Like most parts of the plant, the seeds are covered in tiny barbs that can stick to cloth or fur easily. The seeds spread easily, and even a few of the hardy seeds can cause an outbreak in a garden.

Chemical Solutions for Galium Aparine

Some herbicides have proven to be effective in removing the pesky plant. Contact herbicides containing acetic, fatty or pelargonic acids can scorch off Sticky Willy’s foliage, including its seed leaves. However, these can damage nearby plants, so covering desirable garden plants is recommended, at least until the chemicals dry on the weed foliage.

Glyphosate can be used in the same way, but it’s more important to ensure none of it gets on any other plants.

Green Thumb – What’s That Weed?

As a small child I got a kick out of picking dandelions just to blow away the fluff. Now I pluck them from the lawn in slow motion. Dandelions have a bad rap because they spread so easily, but it’s important to know that their early flowers are a food source for hungry bees emerging from the hive. That fact changed my opinion of dandelions.

Most weeds don’t scream for attention like dandelions. Nevertheless, some have interesting characteristics. Here are the names and descriptions of some you might find in your yard. Most are notorious for their seed production.

Cleavers (Galium aparine) has colorful common names like “Sticky Willie”, “Hitchhikers”, and “Velcro Plant”. It grows fast in gardens, forests and fields. The long, lanky stems crawl along the ground and over other plants, with this interesting feature: fine hook-like hairs on the stems and leaves stick to you like, well, velcro. The plants are hard to pull out because the stems break off easily. This weed is oddly attractive, but you don’t want any plant around that produces 300-400 seeds. Even the tiny white flowers produce burrs tough enough to pass through the digestive tract of animals.

Hairy Bittercress (Cardamine hirsuta) is an inconspicuous spring-loaded thing that waits to be touched. Then it shoots its seeds out forcefully 10 feet or more. It is small but mighty. The plant is a winter annual which means its seeds germinate in the fall and develop into small rosettes that overwinter. In early spring they send up three to eight inch long stalks of small white flowers that produce slender seed pods. An average plant will produce 600 seeds. This one is also a summer annual.

See also  Weed seed dissemination

Pineapple Weed (Matricaria discoidea) gets its name from the pineapple/camomile scent it produces when crushed. A native of northeast Asia, it’s an annual that grows in sunny gravel or compacted soils. Its taproot allows it to survive a harsh location. The flower is a yellow-green cone at the tip of a stem. The plant can grow up to 12 inches tall and looks like a miniature bush with fern-like leaves.

Creeping Spurge (Euphorbia supina) forms a flat mat. I’ve seen them the size of a dinner plate. It’s an annual that often has purple mottling on its leaves. When broken it drips a poisonous, white sap that can irritate the skin and eyes. Wear gloves and pull it out by the tap root. It thrives in full sun and drier soils. In the summer you’ll see it growing from cracks in sidewalks where it stretches out over the hot surface. It would make a dense groundcover, but for one serious flaw. A single plant can produce thousands of seeds.

Common Yellow Woodsorrel (Oxalis stricata) is a common weed that tolerates a wide range of conditions and can grow 6-15 inches tall. It is also called “Sheep’s Clover” because its leaves are similar to clover. The half-inch yellow flowers are followed by erect seed pods that open explosively when touched. It can also form colonies from underground rhizomes. This weed is best controlled by mulching and hand weeding.

Garlic Mustard (Alliaria petiolata) is a highly invasive biennial that smells like garlic when crushed. This plant is a menace because it is allelopathic which means it produces chemicals that inhibit the growth of other plants. The first year’s growth is a small rosette. The second year it shoots up a one to four foot stem that develops flowers. Put on your gloves and pull this out whenever you see it. Don’t leave a flowering plant on the ground because it can set seeds. A big plant can produce thousands.

It’s always best to pull out weeds before they flower. Mother Nature has tricks up her sleeve.

Janice M. Weber – University of Illinois Extension, DeKalb County Master Gardener

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