What is a dandelion?

The common dandelion is a perennial broadleaf weed brought over from Europe, and it’s now found in nearly every lawn in Pennsylvania. Good dandelion control starts with understanding its thick taproot, because that root is why dandelions keep coming back year after year in the same spot.

Dandelions grow as a flat rosette of toothed leaves and send up bright yellow flowers, mostly in spring. Each flower turns into a white puffball of seeds that drift on the wind, which is why a clean lawn next to a weedy one never stays clean for long.

Dandelions aren’t on Pennsylvania’s noxious weed list. They’re edible, early bees use the flowers, and plenty of people don’t mind a few. But in a lawn they crowd out grass and leave bare spots when they die back.

How to identify dandelions

Most people can spot a dandelion in bloom, but it helps to know the plant when it’s just leaves, too.

• Leaves: a flat rosette of long leaves with deep, jagged teeth that point back toward the center.
• Milky sap: break a leaf or flower stalk and white sap oozes out.
• Flowers: one bright yellow head per stalk, 1 to 2 inches across.
• Stalks: hollow and leafless.
• Seed heads: round white puffballs of parachute seeds.
• Root: a thick, fleshy taproot, often a foot or more deep.

Where dandelions grow in Pennsylvania

Dandelions grow almost anywhere with sun, from lawns and gardens to roadsides, fields and the joints in a patio. They’re most common in thin lawns, where seed blowing in has bare soil to land on.

Lawns that are mowed very short, underfed or stressed by drought tend to have the most. Dandelions also tolerate our central PA clay and the freeze-thaw swings of early spring, which is part of why they’re often the first green thing growing in March.

Dandelion look-alikes

Catsear, often called false dandelion, is the most common mix-up. Its leaves are very hairy and less sharply toothed, and its flower stalks are solid, wiry and often branched with more than one flower.

Chicory has a similar rosette in spring but sends up a tall, stiff stem with blue flowers in summer. Hawkweeds have fuzzy leaves without deep teeth, and spiny sowthistle grows a tall, leafy, prickly stem. If you see a flat rosette, a single flower on a hollow stalk and milky sap, it’s a dandelion.

Dandelion control: how to get rid of them

Here’s the timing most people miss: fall is the best time to deal with dandelions, not spring. In September and October, the plant is moving energy down into its root to store for winter, so whatever you do then goes deeper.

Digging and pulling. For a handful of plants, digging is the right answer. Use a long, forked dandelion tool or a narrow trowel and lift out as much of the taproot as you can, ideally when the soil is moist after a rain. If the root snaps, the piece left behind can grow a new plant, so check the spot a few weeks later. Fill the hole with soil and a pinch of grass seed.

Cultural control. A thick lawn is the best long-term fix. Mow at 3 to 3½ inches so the grass shades out seedlings, fertilize based on a soil test, and overseed thin areas in early fall. Bag clippings or mow before flowers turn to puffballs to cut down on seed. Many dandelion problems trace back to a lawn that’s simply too thin.

Chemical control. Selective broadleaf herbicides containing 2,4-D, MCPP (mecoprop), dicamba, triclopyr or fluroxypyr control dandelions in lawns without killing the grass. Fall applications from mid-September through October work best, with a spring treatment after the first big bloom as a backup. Spot-treat rather than blanket-spraying a whole lawn when you can. Avoid dicamba over the root zones of trees and shrubs. Read and follow the label every time; the label is the law, and check that the product is labeled for your lawn type. Applying herbicides for hire in Pennsylvania requires a PA Department of Agriculture pesticide applicator certification, so whole-lawn programs belong with a licensed lawn-care company.

Paver joints. Dandelions in patio and walkway joints are usually a sign the joint sand has washed out. Pull them, then refill joints with polymeric sand to leave less room for seed to sprout.

Keeping dandelions from coming back

New seed will always blow in, so the goal isn’t a lawn that never sees another dandelion. It’s a lawn thick enough that seed has nowhere to start.

Overseed every fall where turf is thin, keep the mower set high, and feed the lawn based on what a soil test says it needs. Pull or dig new rosettes while they’re small, and stay on top of joint sand in patios and walks. After a season or two of that routine, you’ll see far fewer yellow heads in April.

Questions we get about dandelion

Similar weeds

ChicoryCichorium intybusBroadleaf PlantainPlantago majorWhite CloverTrifolium repens