Clasping Coneflower (Amplexicaulis)

The Clasping Coneflower (Amplexicaulis) is generally described as an annual forb/herb. This is native to the U.S. (United States) has its most active growth period in the spring and summer . The Clasping Coneflower (Amplexicaulis) has green foliage and inconspicuous yellow flowers, with an abuncance of conspicuous black fruits or seeds. The greatest bloom is usually observed in the late summer, with fruit and seed production starting in the summer and continuing until fall. Leaves are not retained year to year. The Clasping Coneflower (Amplexicaulis) has a short life span relative to most other plant species and a rapid growth rate. At maturity, the typical Clasping Coneflower (Amplexicaulis) will reach up to 2 feet high, with a maximum height at 20 years of 0 inches.

The Clasping Coneflower (Amplexicaulis) is easily found in nurseries, garden stores and other plant dealers and distributors. It can be propagated by seed. It has a rapid ability to spread through seed production and the seedlings have high vigor. Note that cold stratification is not required for seed germination and the plant cannot survive exposure to temperatures below 32°F. has high tolerance to drought and restricted water conditions.

Uses of : Landscaping, Medicinal, Culinary, etc.

This plant is used mainly for landscape beautification. It has potential for use in cultivated, garden situations, in naturalized prairie or meadow plantings, and along roadsides.

General Characteristics

Clasping coneflower is an annual herb with elongated, bluish, waxy leaves that generally clasp around the stem at the base. The flower heads are similar to those of black-eyed susans, but they are smaller (mostly 1 to 2 inches in diameter). The yellow outer petals droop as the flowers mature, and the cylindrical black center (receptacle) is elongated up to 2 inches in length.

Required Growing Conditions

It is adapted to many soil types, but clasping coneflower generally prefers a moist site. Natural stands are usually found on bottomland areas with a fairly rich soil and ample moisture. It prefers full sun and will not persist in a shaded location.

Clasping coneflower is distributed throughout the South.

Cultivation and Care

A firm seedbed is required. Clasping coneflower germinates best on a clean tilled site that has been firmed with a roller or finishing harrow before planting. Seed can also be planted into a closely mowed, chemically-killed, or burned sod area with a light disking or harrowing that scratches the soil surface. A layer of plant residue on the soil will interfere with seed germination. Broadcast or shallowly drill 2 to 3 grams per 100 square feet (2 to 3 lb/acre) broadcast or shallowly drilled. Seed should be placed close to the soil surface. Cultipacking after planting will ensure good seed to soil contact. Seed will germinate soon after planting and remain as a small, nondescript plant over the winter months.

General Upkeep and Control

Plant growth and seed production are greatly improved by fertilization. Fertilizer should be applied in the spring prior to flowering. Apply according to soil test recommendations. If test results are not available, a rate of 3.5 to 5.5 oz per 100 square feet (100 to 150 lb/acre) of 13-13-13 is adequate for most plantings. For seed production, increase the fertilizer rate to 9 oz per 100 square feet (250 lb/acre). Stands will reseed prolifically for several years, but will gradually decline without soil disturbance. Every two to three years, the site should be disked to control perennial weeds and promote clasping coneflower germination. If necessary, plants can be mowed in the spring before stem elongation begins. Stands that are not disked should be mowed in late summer, and a late fall mowing in is also recommended.

Plant Basics
Growth Rate Rapid
General Type Forb/herb
Growth Period Spring, Summer
Growth Duration Annual
Lifespan Short
Plant Nativity Native to U.S.
Commercial Availability Routinely Available
Physical Characteristics
Bloom Period Late Summer
Displays Fall Colors No
Shape/Growth Form Single Stem
Drought Tolerance High
Shade Tolerance Intolerant
Height When Mature 2
Vegetative Spread None
Flower Color Yellow
Flower Conspicuousness Yes
Fruit/Seed Abundance High
Fruit/Seed Seasonality Summer Fall
Seed Spread Rate Rapid
Gardening Characteristics
Propagations (Ways to Grow) Seed
Moisture Requirements High
Cold Stratification Required No
Minimum Temperature 32
Soil Depth for Roots 6
Toxic to Nearby Plants No
Toxic to Livestock No
After-Harvest Regrowth Rate None
After-Harvest Resprout Ability No
Responds to Coppicing No
Growth Requirements
pH Range 6–7.5 pH
Precipitation Range 10–10 inches/yr
Planting Density 0–0 indiv./acre
Soil Textures Coarse, Fine, Medium
Soil Depth for Roots 6
Minimum Frost-Free Days 120 day(s)
Salinity Tolerance None
CaCO3 Tolerance Medium
Sustainability & Use
Leaf Retention No
Palatability Low
Fire Resistant No
Causes Livestock Bloating None

Source: USDA, NRCS, PLANTS Database,
National Plant Data Center, Baton Rouge, LA 70874-4490 USA