Do you have a lot of dandelion flowers? This is what your lawn is trying to tell you

When opportunity knocks, dandelions answer. That’s one reason they’re so common across much of the landscape. If you discover dandelions infesting your lawn, listen carefully to what they’re telling you to deter the opportunistic weed and take action.

“Dandelions are opportunistic invaders. If they’re showing up in your lawn, it means the dandelion has found an opportunity to grow,” says Quincy Law, assistant professor of horticulture at Iowa State University. “These opportunities include bare spots and conditions that are more favorable for dandelion growth than for turf grasses.”

Law should know. He teaches courses on turf cultivation and care and has researched methods to improve the turf’s ecosystem for optimal health and vitality. He knows what makes a healthy lawn and what the presence of certain weeds says about growing conditions.

What dandelion tells you

Dandelions tell a story about their location. If you have dandelions in your lawn, it may mean that your lawn has one or more of these conditions:

Compacted soil

The soil may be compacted. Grass roots have a hard time penetrating dense, compacted soil. But dandelions develop long taproots to reach nutrients and moisture in the lower soil layers, giving them a competitive advantage over turfgrasses.

Thin lawn

The lawn can be thin. Dandelions have an advantage over lawn grasses because they have less competition. For one thing, dandelion seeds have a better chance of germinating in thin lawns. There is also less competition from lawn grass roots and less risk of being shaded.

Excess soil moisture

The soil may be too wet. Although dandelions are drought tolerant once established, they grow best in moist to wet soil and in full sun. If the soil is waterlogged, the dandelion suddenly has less competition because waterlogged soil weakens the grass’ root system.

How to prevent dandelions

A few dandelion seeds that land on your lawn can quickly take root and turn into many more dandelion seeds under favorable conditions. Here’s how you can help your lawn crowd them out.

Promote a healthy lawn

Reducing dandelion competition starts with promoting a healthy lawn. “A thick, healthy lawn is the best defense against weed invasion, and dandelions are no exception,” Law says. “Dandelions produce abundant windblown seeds that germinate easily,” Law says. A single dandelion plant can produce thousands of seeds annually.

Proper mowing, timely watering and appropriate fertilization will strengthen the lawn. If the soil is compacted, aerate it to improve the health of the lawn’s roots. You can also overseed the lawn to encourage a denser turf, which will crowd out the dandelions and leave fewer bare spots where seeds can sprout.

Mow at the right height

Cutting height is an often misunderstood factor. While mowing flowering dandelions may reduce seed production, some plants adapt and later produce flowers and seed heads below the cut.

“A common mistake homeowners make is mowing too short,” says Law. “Mowing is a plant stress that turf grasses can barely tolerate. The lower the cutting height, the greater the stress. Therefore, it is recommended to mow lawns at the highest setting appropriate for your grass type. Mowing too short will result in more dandelions and other weeds than mowing at the optimal height.”

Choose the right NPK fertilizer mix

While the presence of dandelions can indicate a calcium deficiency in the soil, it can also be an indication of an excess of potassium.

“Dandelions prefer potassium-rich soils and can outcompete turfgrasses in nitrogen-poor conditions,” Law says. “So fertility is an important part of integrated dandelion management.” He recommends following your state’s extension office’s annual nitrogen fertilizer recommendations and applying potassium only when needed.

How to deal with established dandelions

Established dandelions can also be a problem. “Dandelions are a perennial species that form a deep taproot, which allows them to survive difficult environmental conditions and regrow every year,” says Law.

Manual removal is possible if you can remove the taproot, which can grow 12 to 18 inches deep in older specimens. The other alternative is a spot treatment with a broadleaf weed killer, preferably in the fall when the dandelion is preparing for dormancy and transporting nutrients back to the roots.