Also known as Sweet Flag · 480 saves
Acorus
Acorus, the genus most gardeners know as sweet flag. We track 14 varieties; the ones most used by real gardeners.
The 14 most-saved Acorus varieties
Species of Acorus
Each one is a parent of the varieties above.
Track your Acorus in Sow
Save the Acorus you grow and get care reminders timed to your zone.
How to grow Acorus
Whats common across all Acorus varieties in our catalog — drawn from the care records of the 14 most-grown of them.
The Acorus year
- DivideMarch and April100% of varieties
Divide dense clumps every 3-5 years to maintain vigor.
- Spring CleanupFebruary and March86% of varieties
Cut back old, brown foliage to the ground before new growth emerges.
- PlantMarch, April and September71% of varieties
Plant in consistently moist soil or shallow water (up to 6 inches).
Do
- Water regularly to keep soil moist 🌱
- Mulch to retain soil moisture
- Divide every few years for vigorous growth
- Divide clumps every few years
- Mulch to retain moisture and control weeds
Avoid
- Allow soil to dry out completely ❌
- Avoid dry, well-drained soils ❌
- Avoid letting soil dry out completely ❌
- Use high nitrogen fertilizer excessively
What goes wrong with Acorus
| Problem | What you'll see | What to do |
|---|---|---|
| Aphids | Sticky residue and distorted leaves | Spray with neem oil or insecticidal soap |
| None significant | This plant is generally free from pest problems. | No action is typically required. |
| Root rot | Wilting and yellowing leaves | Improve drainage and reduce watering |
| Spider mites | Fine webbing on foliage, speckled leaves | Use insecticidal soap or horticultural oil |
| Root rot | Wilting and browning of rhizomes | Improve drainage and reduce watering frequency |
| None significant | This plant is generally free from disease problems. | No action is typically required. |
| Fungal leaf spot | Dark spots on leaves | Remove affected foliage and improve air circulation |
Making more Acorus
Rhizome division
- Dig up mature clumps in early spring.
- Cut rhizomes into sections with roots attached.
- Plant divisions 1-2 inches deep in prepared soil.
- Water thoroughly and mulch.
- Wait 4-6 weeks for new growth.
Division
- Dig up clump in early spring.
- Divide rhizomes into sections with roots.
- Plant immediately in moist soil.
- Water thoroughly after planting.
- Repeat every 2-3 years for best vigor.
Acorus questions
How many types of Acorus are there?
The Sow catalog tracks 14 distinct Acorus varieties. The most popular — ranked by 480 real gardeners — are shown first above.
What zones does Acorus grow in?
Across its varieties, Acorus 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 Acorus bloom?
Most Acorus varieties bloom in late spring, late spring to early summer, early summer. Staggering early, mid, and late varieties extends the genus's season in one bed.
Which Acorus 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.