Also known as Willowherb · 1 saves
Epilobium
Epilobium, the genus most gardeners know as willowherb. We track 3 varieties; the ones most used by real gardeners.
The 3 most-saved Epilobium varieties
3 species of Epilobium
Each one is a parent of the varieties above.
Track your Epilobium in Sow
Save the Epilobium you grow and get care reminders timed to your zone.
How to grow Epilobium
Whats common across all Epilobium varieties in our catalog — drawn from the care records of the 3 most-grown of them.
The Epilobium year
- Check for PestsJune and July100% of varieties
Inspect foliage for spider mites and aphids during hot, dry spells.
- PruneFebruary and March67% of varieties
Shear the entire plant close to the ground to remove old woody stems and stimulate fresh basal growth.
- DivideMarch and April67% of varieties
Divide established clumps by separating active rhizomes to propagate new plants.
Do
- Prune the plant back hard annually in late winter to stimulate fresh growth.
- Ensure the soil drains rapidly to prevent root rot.
- Grow in full sun to maximize flower production.
- Cut the stems back hard to ground level in late winter or early spring.
- Apply a balanced organic mulch or fertilizer in spring to support new growth.
Avoid
- Do not overwater during the summer once the plant is established.
- Do not apply heavy organic compost or high-nitrogen fertilizers.
- Do not prune heavily during the first year of establishment.
- Do not allow the soil to dry out completely, as drought tolerance is low.
What goes wrong with Epilobium
| Problem | What you'll see | What to do |
|---|---|---|
| Spider mites | Fine webbing and light-colored stippling on the leaves during hot, dry weather. | Apply insecticidal soap or use forceful water sprays to knock them off the foliage. |
| Aphids | Clusters of small insects on tender new growth tips, causing distorted leaves. | Wash them off with a strong jet of water or apply horticultural oil. |
| Rabbits and Deer | Chewed stems and foliage, particularly on young plants or those receiving summer water. | Install physical barriers or use scent-based repellents to protect vulnerable growth. |
| Slugs and snails | Large, ragged holes chewed in the soft lower foliage. | Handpick pests at night or apply targeted organic iron phosphate baits around the base. |
| Root rot | Wilting, yellowing foliage and plant decline caused by soggy, poorly drained soil. | Ensure sharp drainage, plant in raised beds if necessary, and avoid summer overwatering. |
| Powdery mildew | White, powdery coating on leaves in crowded, humid, or shaded conditions. | Improve air circulation around the plant and maximize sun exposure. |
Making more Epilobium
Seed
- Sow seeds in spring in a moist seed-starting mix.
- Maintain a consistent temperature and keep the soil damp.
- Prick out seedlings into individual pots once they are large enough to handle.
- Acclimatize and transplant outdoors after the last frost.
Division
- Locate healthy basal rosettes in early spring.
- Carefully lift the clump with a garden fork.
- Divide the rosettes using a sharp knife, ensuring each section has roots.
- Replant immediately into moist soil and water thoroughly.
Epilobium questions
How many types of Epilobium are there?
The Sow catalog tracks 3 distinct Epilobium varieties. The most popular — ranked by 1 real gardeners — are shown first above.
What zones does Epilobium grow in?
Across its varieties, Epilobium covers USDA Zones 4–10. Individual varieties differ — each plant page lists its exact range, and Sow filters the catalog to your zone automatically.
When does Epilobium bloom?
Most Epilobium varieties bloom in summer. Staggering early, mid, and late varieties extends the genus's season in one bed.
Which Epilobium should I choose?
Start from the most-saved varieties above — popularity across thousands of gardens is a strong signal of reliability — then filter by your zone and sun. In the Sow app you can preview any of them in a photo of your actual yard before you buy.