Weeds in Flowers

Hairy Bittercress

• Hairy bittercress (Cardamine hirsuta) is an annual weed that shows up in flower beds or container plantings in summer. Bittercress has a mounding growth habit and develops several petioles that extend up to 12 inches high. The petioles are hairy and develop clusters of small white flowers at the end throughout the summer. Hairy bittercress reproduces rapidly via seeds and can quickly take over your flower garden if left untreated. Apply topical herbicide to bittercress as soon as you identify it in your flower garden; there are several broad-spectrum herbicides that kill hairy bittercress.

Dandelion

• Dandelion (Taraxacum officinale) is a common perennial weed that has three distinct stages of development. Seedlings emerge as small, oval leaves, which are succeeded by leaves that have toothed edges and slightly hairy leaves. Mature plant leaves form a rosette and contain a bright yellow flower that grows on a hollow stalk. Dandelions reproduce by developing a single seed head attached to a long stalk that stands tall above the rest of the weed. The seed head then produces thousands of tiny, feather-like seeds that are transported by wind, which makes it challenging to control dandelions in flower gardens. Dandelions are best controlled by hand pulling or digging before they develop seeds. Spot treatment with a broad-spectrum herbicide is also effective for treating dandelions in flower gardens.

Wire Grass

• Wire grass (Cynodon dactylon), also called Bermuda grass, can be a difficult weed to remove from flower gardens. Wire grass is a perennial warm season grass that spreads through both rhizomes and stolons that produce seeds. The grass forms thick mounds of growth, and the root system is extensive and thick, making large patches of wire grass difficult to remove manually. Persistent manual control is, however, the best method of control in established flower gardens. The additional use of black gardening cloth and light mulching that limits sunlight on weeds are both effective ways of controlling wire grass around delicate flowers, according to the University of California.