Coppery St. Johnswort (Denticulatum)

The Coppery St. Johnswort (Denticulatum) is generally described as a perennial forb/herb. This is native to the U.S. (United States) has its most active growth period in the summer . The Coppery St. Johnswort (Denticulatum) has green foliage and inconspicuous yellow flowers, with a moderate amount of conspicuous brown fruits or seeds. The greatest bloom is usually observed in the early summer, with fruit and seed production starting in the summer and continuing until summer. Leaves are not retained year to year. The Coppery St. Johnswort (Denticulatum) has a moderate life span relative to most other plant species and a slow growth rate. At maturity, the typical Coppery St. Johnswort (Denticulatum) will reach up to 2 feet high, with a maximum height at 20 years of 0 inches.

The Coppery St. Johnswort (Denticulatum) is not commonly available from nurseries, garden stores and other plant dealers and distributors. It can be propagated by container, sprigs. It has a slow 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 2°F. has medium tolerance to drought and restricted water conditions.

Plant Basics
Growth Rate Slow
General Type Forb/herb
Growth Period Summer
Growth Duration Perennial
Lifespan Moderate
Plant Nativity Native to U.S.
Commercial Availability No Known Source
Physical Characteristics
Bloom Period Early Summer
Displays Fall Colors No
Shape/Growth Form Single Crown
Drought Tolerance Medium
Shade Tolerance Intermediate
Height When Mature 2
Vegetative Spread None
Flower Color Yellow
Flower Conspicuousness Yes
Fruit/Seed Abundance Medium
Fruit/Seed Seasonality Summer Summer
Seed Spread Rate Slow
Gardening Characteristics
Propagations (Ways to Grow) Container, Sprigs
Moisture Requirements Medium
Cold Stratification Required Yes
Minimum Temperature 2
Soil Depth for Roots 10
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 4.8–6.4 pH
Precipitation Range 36–36 inches/yr
Planting Density 4800–7000 indiv./acre
Soil Textures Coarse, Fine, Medium
Soil Depth for Roots 10
Minimum Frost-Free Days 185 day(s)
Salinity Tolerance None
CaCO3 Tolerance Low
Sustainability & Use
Leaf Retention No
Fire Resistant No
Causes Livestock Bloating None

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