Crocus
Plant corms in autumn (Sep-Oct) at the correct depth; don't confuse this genus with the highly toxic Colchicum autumnale, sometimes also called "autumn crocus" despite being unrelated.
Care
Needed for the flowers to open fully.
Dry summer dormancy while the corms rest is essential; standard bulb watering during active growth.
Free-draining soil of any reasonable fertility; dislikes waterlogging, especially during summer dormancy.
Not applicable — if naturalised in grass, hold off mowing for at least 6 weeks after flowering to let the corm recharge for next year.
A high-potash feed while the leaves are green after flowering helps a naturalised drift keep going. In grass, the more important rule is not to mow until the foliage has yellowed.
Lift congested clumps when dormant in summer and separate the cormlets clustered round each corm. Many species also seed themselves into grass and gravel, which is how a drift thickens on its own.
Month by month
Months change with the climate: in southern Italy tomatoes go out two months earlier than in England.
- FebruaryMain flowering season for most garden crocus.
- AprilIf naturalised in grass, hold off mowing until foliage has died back naturally.
- SeptemberPlant corms in autumn, about 8-10cm deep.
Months based on climate: UK. Your choice stays on this device.
- FebruaryMain flowering season for most garden crocus.
- AprilIf naturalised in grass, hold off mowing until foliage has died back naturally.
- SeptemberPlant corms in autumn, about 8-10cm deep.
Months based on climate: Northern Italy. Your choice stays on this device.
- JanuaryMain flowering season for most garden crocus.
- MarchIf naturalised in grass, hold off mowing until foliage has died back naturally.
- SeptemberPlant corms in autumn, about 8-10cm deep.
Months based on climate: Central Italy. Your choice stays on this device.
- JanuaryMain flowering season for most garden crocus.
- MarchIf naturalised in grass, hold off mowing until foliage has died back naturally.
- OctoberPlant corms in autumn, about 8-10cm deep.
Months based on climate: Southern Italy and islands. Your choice stays on this device.
Common problems
How to spot it. Corms disappear or are scattered on the surface soon after planting.
What to do. Cover freshly planted corms with wire mesh if this is a persistent problem.
How to spot it. In waterlogged soil.
What to do. Improve drainage.
How to spot it. A similar-looking, unrelated bulb flowering leafless in autumn.
What to do. Colchicum autumnale is a completely different genus and highly toxic if eaten — despite the common-name overlap it is not a Crocus and shouldn't be handled the same way around children, pets, or livestock.
Questions
Crocus: is it hardy?
H6: Hardy in the vast majority of UK gardens. It survives down to −20 °C.
Can it grow in a pot?
Very popular in pots, bowls, and for naturalising in grass/lawns.
Crocus: when do you prune it?
Not applicable — if naturalised in grass, hold off mowing for at least 6 weeks after flowering to let the corm recharge for next year.
Crocus: when does it flower?
In the climate of UK it flowers in January–March.
When do you feed it?
A high-potash feed while the leaves are green after flowering helps a naturalised drift keep going. In grass, the more important rule is not to mow until the foliage has yellowed. Feeding months, UK: March.