Spring vs autumn forage
Both are gaps worth filling and they matter for different reasons. Spring decides how many colonies exist; autumn decides how many survive.
Which to choose
Both, and if you can only do one, do the one your area lacks. Most urban gardens have some spring bulbs and no autumn forage; most farmland has neither. The two cheapest interventions in bee gardening are leaving dandelions in April and leaving ivy in October.
Why these get compared
Gardeners asked to plant for bees usually plant for summer, and the two shoulder seasons are where the difference is actually made.
Where they differ
| Axis | Spring forage | Autumn forage | Why it matters |
|---|---|---|---|
| What it enables | Colony founding and build-up | Winter survival and next year's queens | A bumblebee queen with no spring pollen founds no colony at all. A colony with no autumn forage enters winter weak. |
| Which resource matters | Pollen above all — larvae are made of it | Both, with pollen for winter bees and nectar for stores | Spring is a pollen problem; autumn is both. |
| Who depends on it | Emerging bumblebee queens, spring mining bees, mason bees | Ivy bee, late carder bees, honey bee colonies provisioning | Different communities entirely, which is why filling one gap does not fill the other. |
| Key plants | Willow, crocus, dandelion, blackthorn, coltsfoot, lungwort | Ivy, sedum, michaelmas daisy, fatsia, elaeagnus, devil's-bit scabious | Very little overlap. |
| Effect if missing | Fewer colonies exist | Colonies that exist are weaker and fewer queens are mated | Spring failure removes colonies; autumn failure removes their quality. |
| Cheapest fix | Do not mow dandelions in April | Do not cut ivy off walls in October | Both of the highest-value interventions cost nothing and involve doing less. |
Where the difference is overstated
Summer's importance relative to either. A garden full of June flowers and nothing in February or October is a feeding station during the one period when food is least scarce.
Sources
- Assessment Report on Pollinators, Pollination and Food Production — Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) (2016) · Systematic review Link
- Field Guide to the Bees of Great Britain and Ireland — Bloomsbury (2015) · Field guide
- Bumblebees: Behaviour, Ecology, and Conservation — Oxford University Press (2010) · Monograph
How sources are selected and weighted is set out in the sources and evidence policy.