Overwintering guide
How to overwinter ageratum houstonianum 'blue horizon'
Winter watering
If you do keep it going indoors, water sparingly — just enough that the compost never dries out completely — and do not feed until growth restarts in spring.
The mistake that kills ageratum houstonianum 'blue horizon' in winter
Leaving ageratum houstonianum 'blue horizon' outside over winter expecting it back in spring. As an annual it will not return — seed or cuttings are the only way to carry it forward.
More ageratum houstonianum 'blue horizon' care
- Overwintering hawaii blue flossflower — the species this cultivar belongs to
- Full ageratum houstonianum 'blue horizon' care guide
- Ageratum houstonianum 'Blue Horizon' temperature range
- How often to water ageratum houstonianum 'blue horizon'
- How to prune ageratum houstonianum 'blue horizon'
- Common ageratum houstonianum 'blue horizon' problems & fixes
- Best plant identifier apps — tested and ranked
Overwintering ageratum houstonianum 'blue horizon' — FAQ
Does ageratum houstonianum 'blue horizon' need to come indoors for winter?
Ageratum houstonianum 'Blue Horizon' is grown as an annual — it is frost-tender and naturally finishes at the end of the season, whatever your zone. In most climates ageratum houstonianum 'blue horizon' is grown as an annual, so there is usually nothing to overwinter — the plant completes its life cycle and dies back with the first frosts. If you want to carry it over, lift it before the first frost and grow it on in the brightest window you have, or take cuttings; otherwise collect seed and start fresh in spring, which is what most growers do.
When should I move ageratum houstonianum 'blue horizon' for winter?
Lift or take cuttings before the first frost — or let it finish and save seed.
How often should I water ageratum houstonianum 'blue horizon' in winter?
If you do keep it going indoors, water sparingly — just enough that the compost never dries out completely — and do not feed until growth restarts in spring.
What kills ageratum houstonianum 'blue horizon' over winter?
Leaving ageratum houstonianum 'blue horizon' outside over winter expecting it back in spring. As an annual it will not return — seed or cuttings are the only way to carry it forward.