How to Care for Ageratum

Ageratum (Ageratum houstonianum), native to Mexico, is prized for its easy growing habits, ability to adapt to partial shade and because it's one of the few annuals available in blue. A hardy, compact little summer bloomer, ageratum is often grown in flower beds, along borders or mixed with other colorful annuals in a patio container or window box. In addition to blue, ageratum's button-shaped blooms are also available in pink and white.

Mulch

General-purpose, time-release garden fertilizer

Plant ageratum in bright sunlight or partial shade, depending on your climate. Although ageratum blooms best with plenty of sunlight, ageratum benefits from afternoon shade in climates with hot, dry summers.

Water ageratum deeply enough to saturate the roots when the top of the soil feels slightly dry. Don't allow the soil to remain soggy, but water often enough that it doesn't dry completely. A 1- to 2-inch layer of mulch such as bark chips or dry grass clippings keeps the soil moist and saves water.

Fertilize ageratum after planting time in spring. Use a general-purpose, time-release fertilizer applied according to the rate recommendations on the package. One feeding is enough to provide nourishment for ageratum throughout the growing season.

Pinch off wilted ageratum blooms, as deadheading keeps ageratum blooming until the first frost in autumn. Remove the blooms as soon as they wilt and don't give ageratum an opportunity to go to seed by waiting until the flowers are completely dry.

Although ageratum can be started indoors by seed, most gardeners prefer the instant color provided by planting bedding plants. Ageratum is readily available in garden centers and nurseries, usually for a reasonable price.

If you choose to plant ageratum seeds indoors, use peat pots or another form of plantable pot, as ageratum seedlings don't easily tolerate transplantation.