Also known as Twinspur · 87 saves
Diascia
Diascia, the genus most gardeners know as twinspur. We track 3 varieties; the ones most used by real gardeners.
The 3 most-saved Diascia varieties
2 species of Diascia
Each one is a parent of the varieties above.
Track your Diascia in Sow
Save the Diascia you grow and get care reminders timed to your zone.
How to grow Diascia
Whats common across all Diascia varieties in our catalog — drawn from the care records of the 3 most-grown of them.
The Diascia year
- PruneAugust67% of varieties
Shear plant back by one-third in mid-summer to rejuvenate and promote fall blooms.
- DeadheadJune–September67% of varieties
Remove spent flower spikes to encourage continuous blooming.
- FertilizeMay–August67% of varieties
Feed monthly with a balanced liquid fertilizer during the growing season.
Do
- Water consistently, keeping soil moist but not soggy 🌱
- Prune lightly after flowering to maintain shape
- Apply balanced fertilizer monthly during active growth
- Give it sharp drainage 🌱
- Shear back after the first flush ✂️
Avoid
- Avoid overwatering to prevent root rot ❌
- Don’t fertilize in late fall or winter
- Never place in deep shade, as it needs full sun
- Plant it in wet winter soil ❌
What goes wrong with Diascia
| Problem | What you'll see | What to do |
|---|---|---|
| Aphids | Sticky residue and distorted leaves | Spray with insecticidal soap or neem oil |
| Spider Mites | Fine webbing on leaves | Increase humidity and apply miticide if needed |
| Generally pest-free | No significant insect damage is typical | Monitor only; no routine treatment needed |
| Slugs and snails | Ragged holes chewed in the foliage and young shoots, accompanied by silvery slime trails. | Apply iron phosphate bait around the base of the plants or handpick pests during damp evening hours. |
| Root Rot | Wilting despite watering, darkened roots | Improve drainage and reduce watering frequency |
| Root and crown rot | The clump collapses at the base, almost always after a wet winter rather than a cold one | Improve drainage or grow it on a raised gritty bed; winter wet is what kills it |
| Root and stem rot | Wilting, yellowing foliage and blackening stems near the soil line, despite moist soil. | Remove affected plants immediately and improve soil drainage by incorporating sand or gravel before replanting. |
Making more Diascia
Seed sowing
- Surface sow seeds in well-draining soil — 2 weeks
- Keep soil moist and place in bright, indirect light
- Maintain temperature around 65-75°F (18-24°C)
Cuttings
- Take 4-inch softwood cuttings in early summer
- Dip cuttings in rooting hormone
- Place in humid environment for 4-6 weeks
Diascia questions
How many types of Diascia are there?
The Sow catalog tracks 3 distinct Diascia varieties. The most popular — ranked by 87 real gardeners — are shown first above.
What zones does Diascia grow in?
Across its varieties, Diascia covers USDA Zones 5–10. Individual varieties differ — each plant page lists its exact range, and Sow filters the catalog to your zone automatically.
When does Diascia bloom?
Most Diascia varieties bloom in late spring to fall, summer. Staggering early, mid, and late varieties extends the genus's season in one bed.
Which Diascia 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.