Turf Tips

Difficult to Control Weeds

How do I Prevent Weed Problems?

Promoting a healthy lawn is the best defense against having severe weed problems. Proper mowing and watering, regular fertilization and core cultivation when necessary are key ingredients in building a healthy lawn. The use of pest control materials as tools to control weeds and other pest problems will help to protect grass plants and ensure vigorous growth in a lawn. Most broadleaf weeds that invade lawns can be effectively controlled with the use of selective weed control materials that are currently available.

These products are referred to as selective because they only affect the weeds and do not harm the grass plants in a lawn. There are, however, some weeds that are extremely difficult to control and some that cannot be controlled with the use of these materials. Special attention and care are often needed to control these persistent weeds. Let's dive into these difficult-to-control weeds.

Types of Difficult-to-Control Weeds

Speedwells Veronica spp.

Several types of Speedwell species invade home lawns. Some are annual plants that reproduce from seed and others are perennial plants that can reproduce by seed, rhizomes and creeping stems. All are low growing with small leaves. Perennial species are generally more difficult to control.

Violets Viola spp.

The two types of Violets most commonly found on home lawns include field violet, an annual weed, and sweet violet, a perennial weed. Violets are distinguished by their heart-shaped leaves and their white, yellow, or purple flowers. Both types of violets can be extremely difficult to control.

Ground-Ivy or Creeping Charlie

Formally called Glechoma hederacea L., this is a perennial weed that has a creeping growth habit. It lays prostrate along the ground with square stems and roots at every node. Its leaves are round with toothed edges, and its stems and leaves produce a mint-like odor when crushed. Ground-Ivy is more readily controlled than the previous two types of weeds; however, like most of the weeds mentioned, it will take an ongoing effort by a lawn care professional to control it.

Other Difficult-to-Control Weeds

Other weeds found on home lawns that are considered difficult to control include field bindweed, wild strawberry, mossy stonecrop, yarrow, and knotweed. A combination of proper cultural practices, adequate nutrition and a progressive weed control program that may include repeat applications of government-regulated weed control materials will help to control these weeds over time. It may require several years of effort by a lawn care professional and the homeowner before adequate control of these weeds is achieved.

Weeds Resistant To Selective Methods of Control:

• Creeping Bellflower Campanula rapunculoides L.
• Goutweed or Bishopweed Aegopodium podagraria L.
• Japanese Knotweed Polygonum cuspidatum Sieb. Zucc.
• Field horsetail Equisetum arvense L.

These weeds are seldom a concern in home lawns; however, when they do appear, they can present a major problem. All are extremely persistent perennial plants. All reproduce by underground stems called rhizomes that make them very difficult to control. They cannot be selectively controlled on a lawn using weed control materials. They can, however, be effectively dug out of a lawn as long as care is given to remove entire plants, including all underground reproductive structures (seeds, rhizomes, roots).

Your Local Weed Man Can Help!

Your local Weed Man is a trained specialist. He can properly identify any broadleaf weeds that exist on your lawn and determine the most suitable method for their control. Contact your local Weed Man if you would like to have your property inspected free of charge.