Why botanical family is the most useful thing to know about a bee plant

Flower shape is inherited, and flower shape gates who can feed

The single most under-appreciated fact in bee gardening is that honey bees have short tongues and cannot reach into a deep corolla. That is why red clover is a long-tongued bumblebee plant and white clover is a honey bee crop, despite being the same genus. Corolla depth, the arrangement of florets and whether nectar sits exposed or protected are all largely inherited at family level — which makes family the most predictive single thing you can know about a plant you have never met.

• Asteraceae — composite heads of hundreds of shallow florets. Accessible to almost everything, and the family that carries late summer.
• Lamiaceae — two-lipped tubes with a landing platform and the anthers above. Nearly every member is worth planting, and tube depth varies usefully across the family.
• Apiaceae — flat umbels with completely exposed nectaries. No tongue length required at all, which serves the small insects most flowers exclude.
• Fabaceae — a keel the visitor must physically force open. Selective by design, which is why corolla depth decides everything here.
• Ranunculaceae — open bowls of accessible pollen in the depths of winter. Mostly pollen rather than nectar, and that is exactly what an emerging queen needs.

Nectar and pollen are different resources and must be counted apart

Nectar is carbohydrate and fuels adult flight; pollen is protein and feeds larvae. A garden supplying only the first looks busy and starves the next generation. This is why every plant record in this catalogue rates the two separately, and why a single bee-friendly score would be actively misleading.

The clearest examples are the ones that give only one. Gorse and broom offer no nectar at all and enormous quantities of pollen. Poppies are the same. Several honeysuckles are the reverse. None of those facts survives being compressed into one rating.

The specialists are the reason wild plants matter

A substantial minority of bee species are oligolectic — they collect pollen from one plant family or genus and will visit almost nothing else. Most of those specialisms attach to wild rather than garden plants, which is why knapweed, scabious, bird's-foot trefoil and viper's bugloss support solitary bees that a border of cultivars never reaches. It is also why removing dandelions and ragwort from a landscape costs more than it looks like it should.

How to use this in a real garden

Pick across families rather than across colours. Three Lamiaceae plants chosen for succession — rosemary in February, thyme in May, agastache in September — cover eight months between them. Add one Ranunculaceae for deep winter, one Asteraceae for late summer and one Rosaceae tree or shrub for the spring blossom, and a small garden has a genuinely continuous year from six plants.

Then check the gaps rather than admiring the peaks. A garden's value to bees is limited by its worst month, and the useful question is never what to add in June.