Getting the Best of Catchweed Bedstraw

Galium aparine is an easily identifiable, edible, annual, and native weed of Pennsylvania. This weed germinates in the cooler temperatures of early to late spring and again in late summer to early fall. It prefers moist, fertile soil in full to part shade, though it can be found in sunny sites. In home gardens, it is most often seen in landscape beds and on the edge of wooded areas.

The common names indicate this weed's most identifiable and annoying feature. Along the square stems, the leaves, and the mature seed pods are hook-like hairs that stick to almost everything they touch. Scratchy hairs can irritate people with sensitive skin. Even though a mature specimen can reach six feet, its stems are fragile. It will fall on itself as it grows and creates a low, sprawling mat. The stickiness of the plant allows it to attain some height when it scrambles onto and up through nearby stronger-stemmed shrubs and perennials.  

Like many native plants that we now refer to as weeds, sticky willy was historically a very useful plant. It became a mattress filler (hence, the nickname "bedstraw") because it does not become compacted readily. It is an edible plant. The young leaves were eaten both raw and cooked. The fruits were dried, roasted, and consumed as a substitute for coffee. Native Americans used it medicinally. It is used to this day to treat medical conditions throughout much of the world.

The second most identifiable characteristic is its structure. Its green leaves are whorled, and there is a fair amount of space between them along the green square stems. The plant does not branch excessively. Young leaves are in whorls of about four leaves. Mature plants have six to eight leaves on each whorl. The narrow leaf blades are oval to lanceolate. They are sessile (lacking a petiole). Each leaf can be 1-inch long and ends in a sharp point.

Tiny green or white four-petalled flowers will develop either in the leaf axils (where the leaf meets the stem) or terminally. The first flowers are generally seen in Pennsylvania in late May to mid-June depending on weather conditions. The flowers are in groups of three to five. The inflorescence is a cyme, meaning that the flowers grow together on their stalk, with the terminal flower maturing first. After being pollinated by beetles or flies, round fruits in 2 halves develop. Each fruit contains a seed and has the plant's notorious backward-hooking bristles. The seed pods are burrs. Animals disperse the mature brown burrs after attaching to the animal's fur or human clothing. A mature catchweed bedstraw plant can make 300 or more seeds. The seeds are viable for just a couple of years.

Catchweed bedstraw has shallow fibrous roots. When it is small, it is easy to pull up the entire plant – roots and all. As it ages, the root system becomes stronger than the weak attachment of the stem to the root. Be careful to get all the roots lest it will regrow. Wear gloves. Use a hoe. As with all annual weeds, it is best to eradicate them from your garden before their seeds develop and are dispersed. Another reason why it is wise to remove it when it's small is that it may be difficult to remove it without damaging the nearby plants to which it may become attached. If you are so inclined, pre-emergent herbicides can be effective on landscape beds to prevent germination. Follow all label directions and remember that more is not better.

Smooth bedstraw (Galium mollugo) is a related plant with the same above-ground leaf and overall structure as catchweed bedstraw but without the bristles on the leaves, stems, and seedpods. Smooth bedstraw propagates by seed and spreads readily through underground stolons and rhizomes (unlike catchweed bedstraw).