American Tarwort (Cernua)

The American Tarwort (Cernua) is generally described as a perennial shrub. This is native to the U.S. (United States) has its most active growth period in the summer . The greatest bloom is usually observed in the late spring, with fruit and seed production starting in the summer and continuing until summer. Leaves are retained year to year. The American Tarwort (Cernua) has a moderate life span relative to most other plant species and a slow growth rate. At maturity, the typical American Tarwort (Cernua) will reach up to 3 feet high, with a maximum height at 20 years of 3 feet.

The American Tarwort (Cernua) is not commonly available from nurseries, garden stores and other plant dealers and distributors. It can be propagated by bare root, container, seed. It has a moderate ability to spread through seed production and the seedlings have medium vigor. Note that cold stratification is not required for seed germination and the plant cannot survive exposure to temperatures below -23°F. has high tolerance to drought and restricted water conditions.

Plant Basics
Growth Rate Slow
General Type Shrub
Growth Period Summer
Growth Duration Perennial
Lifespan Moderate
Plant Nativity Native to U.S.
Commercial Availability No Known Source
Physical Characteristics
Bloom Period Late Spring
Displays Fall Colors No
Shape/Growth Form Multiple Stem
Drought Tolerance High
Shade Tolerance Intolerant
Height When Mature 3
Flower Color Yellow
Flower Conspicuousness No
Fruit/Seed Abundance Medium
Fruit/Seed Seasonality Summer Summer
Seed Spread Rate Moderate
Gardening Characteristics
Propagations (Ways to Grow) Bare Root, Container, Seed
Moisture Requirements Low
Cold Stratification Required No
Minimum Temperature -23
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 7–8.5 pH
Precipitation Range 9–9 inches/yr
Planting Density 10–3000 indiv./acre
Soil Textures Coarse, Fine, Medium
Soil Depth for Roots 6
Minimum Frost-Free Days 160 day(s)
Salinity Tolerance Low
CaCO3 Tolerance High
Sustainability & Use
Leaf Retention Yes
Palatability Low
Fire Resistant No
Causes Livestock Bloating None

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