Deno’s GardenMy Garden

Hypericum densiflorum

Bushy St. Johnswort · Dense St. Johnswort

Family HypericaceaeGenus Hypericum

A bushy shrub of narrow, crowded green leaves with a few bright yellow five-petalled flowers
FlowerBob SchwartzCC BY 4.0
A line drawing of leafy shoots ending in flower clusters, with a five-petalled flower and a pointed capsule
IllustrationBritton, N.L., and A. Brown. 1913. An illustrated flora of the northern United States, Canada and the British Possessions. 3 vols. Charles Scribner's Sons, New York. Vol. 2: 530. Courtesy of Kentucky Native Plant Society. Scanned by Omnitek Inc.Public domain

About the plant

What it is and where it grows — not part of any germination protocol.

The plant

Habit
PerennialExtension Gardener Plant Toolbox
Habit
shrubPlants of the World Online
Height
2-7 ft0.6-2.1 mExtension Gardener Plant Toolbox
Spread
3-6 ft0.9-1.8 mExtension Gardener Plant Toolbox
Flower
Gold/YellowExtension Gardener Plant Toolbox
Blooms
SummerExtension Gardener Plant Toolbox
Native range
Native to the lower 48 statesPLANTS Database
Hardiness zones
3-8Extension Gardener Plant Toolbox

Growing conditions

Sun
Full sun; Partial ShadeExtension Gardener Plant Toolbox
Soil
Clay, Loam (Silt), Sand, Shallow RockyExtension Gardener Plant Toolbox
Soil pH
Acid (<6.0)Extension Gardener Plant Toolbox
Moisture
Good Drainage, Moist, Occasionally DryExtension Gardener Plant Toolbox
Watering
Drought tolerance: LowPLANTS Database

Toxicity is noted only where a source states it. No note here is not a finding of safety.

Sources: Extension Gardener Plant Toolbox — NC State Extension; Plants of the World Online — Royal Botanic Gardens, Kew; PLANTS Database — USDA NRCS.

Protocol

DerivedN. C. Deno, 1993

Difficulty High Rated by us, not by the source.

  1. Sow and cover

    Temperature: 70°F 21°C

No stated waiting before sowing. Then 10 days to germinate.

25% germination in 4–10 days.

Seed Germination Theory and Practice, 2nd ed. — N. C. Deno, 1993 · Ch. 20, Hypericum p. 154Public domain
Show the original text
Hypericum (Hyperiaceae). H. densiflorum germ. 70(25-50% in 4-10 d) and 40(none) using fresh seed or seed DS 6 m at 70 or 40. In view of the photoresponse with
Seed Germination Theory and Practice, 2nd ed., Ch. 20, Hypericum p. 154. Quoted exactly. Every value on this card comes from this record, except the difficulty rating, which is ours; the step names come from a fixed list.

How each step is done, in Deno’s words, and what Verified and Derived mean.

Germination trials

Readers’ own records of sowing this species, published after review. Share your trial · All trials

Add to My Garden

View species page