Butterfly bush care guide: when & how to prune, fertilize and spray
Buddleja davidii · USDA zones 5–9
Fast-growing summer bloomer that attracts butterflies. It flowers on new wood, so cut it back hard every spring. It can self-seed invasively in some regions; seedless cultivars (e.g. 'Lo & Behold', Pugster) are better choices.
☀️ Sun
Full sun.
💧 Water
Drought-tolerant once established; hates wet winter soil.
🪱 Soil
pH 6.0–7.0. Well-drained, even poor soil. Avoid rich soil and heavy feeding. They make floppy growth.
How and when to prune butterfly bush
Cut back hard
When: from 2 weeks before to 2 weeks after the last spring frost.
- zones 3–5: about Apr 26 – May 24
- zones 6–7: about Apr 1–29
- zones 8–10: about Feb 11 – Mar 11
Hard pruning keeps it compact and produces the most flowers on new stems.
- Wait for the first green buds so you know where live wood is. This is usually later than other shrubs.
- Cut all stems back to 12–18 in (30–45 cm) from the ground, just above a pair of buds.
- Remove any dead stems entirely.
Tools: Loppers, Pruning saw
Caution: Don't cut back in fall. Hollow stems let water into the crown.
Deadhead through summer
When: 12–14 weeks after the last spring frost, then every 4 weeks (3 times a season).
- zones 3–5: about Aug 2–16
- zones 6–7: about Jul 8–22
- zones 8–10: about May 20 – Jun 3
Removing spent flower spikes prevents self-seeding and keeps new flowers coming.
- Snip faded flower spikes back to the next pair of side buds.
Common butterfly bush problems and how to fix them
Winter death
Signs: No new growth by late spring.
What to do: Wait. Butterfly bushes leaf out late. Scratch the bark to check for green before giving up.
Butterfly bush care FAQ
When should I prune butterfly bush?
Cut back hard: from 2 weeks before to 2 weeks after the last spring frost (around Apr 1–29 in zones 6–7). Deadhead through summer: 12–14 weeks after the last spring frost (around Jul 8–22 in zones 6–7). Fast-growing summer bloomer that attracts butterflies. It flowers on new wood, so cut it back hard every spring. It can self-seed invasively in some regions; seedless cultivars (e.g. 'Lo & Behold', Pugster) are better choices.
What soil does butterfly bush need?
Well-drained, even poor soil. Preferred pH 6.0–7.0. Avoid rich soil and heavy feeding. They make floppy growth.
How much sun and water does butterfly bush need?
Sun: Full sun. Water: Drought-tolerant once established; hates wet winter soil.
What are common butterfly bush problems?
Winter death: No new growth by late spring. Wait. Butterfly bushes leaf out late. Scratch the bark to check for green before giving up.
More flowering shrubs care guides
Timings are given relative to your average frost dates, with examples for typical US climates. Always read and follow product labels.