Shrubby St. Johnswort (Hypericum prolificum)-Hort Answers - University of Illinois Extension
University of Illinois Extension

University of Illinois Extension

Hort Answers

Shrub

Shrubby St. Johnswort
Hypericum prolificum

Shrubby St. Johnswort form
Shrubby St. Johnswort form
 
Features
Bright yellow flowers (June-August); bluish green leaves in summer. 
 
Culture
Full sun to partial shade; tolerates both wet and dry sites; tolerates alkaline soil. 
 
Cultivars
 
 
Mature Height
3-4 Feet
 
Size
Small
 
 
Mature Width
3-4 Feet
 
Mature Form
Rounded with erect stems 
 
Native To:
United States (and Illinois) 
 
USDA Hardiness Zone
4 - 8 
 
Soil Conditions
Dry
Moist, Well-Drained
Wet
 
 
Tolerance
Alkaline Soil
Dry Sites
Salt
Soil Compaction
Wet Sites
Wind
 
 
Exposure/Light Requirements
Full Sun
Partial Sun/Shade
 
 
Uses
Border
Foundation
Massing
Specimen
 
 
Foliage Color
Green
 
 
Fall Foliage Color
Green
 
 
Pests and Problems
 
Additional Notes

 

 
Related Resources
Home, Yard & Garden Pest Guide
Illinois Commercial Landscape and Turfgrass Pest Management Handbook
U of IL - Distance Diagnosis through Digital Imaging
U of IL - Plant Clinic