Corolla

Definition

Corolla depth against tongue length is the most under-appreciated fact in bee gardening. A honey bee's tongue is around 6 mm and a garden bumblebee's up to 16, so a 9-10 mm corolla admits one and excludes the other. Comfrey, foxglove, summer honeysuckle and red clover are all excellent nectar plants that most bees cannot use through the front door.

Where the word gets used loosely

'Attracts bees' on a plant label means very little without knowing which bees. A deep-corolla plant serves long-tongued bumblebees and, through robbing holes, whoever comes along afterwards.

Honey records that discuss this

• Clover honeyWarm, mild and rounded — sweet with a faint cinnamon-and-hay note underneath. The taste most English-speaking readers picture when they read the word honey.
• Meadow honeySoft, warm and floral with a hay-and-clover base — recognisably a summer field, and gentler and less resinous than mountain honey.

Plant records that discuss this

• LavenderAn unusually good nectar plant relative to its pollen offering. Bees visiting lavender are mostly there for nectar, which is why it supports adult foragers well and contributes less to brood rearing.
• White cloverOne of the very few plants that is both a top-tier nectar source and a substantial pollen source, over a long season, at landscape scale.
• FoxgloveHigh value to a narrow group. This is exactly the plant a 'bee friendly' score would misrepresent: excellent for long-tongued bumblebees, largely irrelevant to honey bees.
• Sweet chestnutAn exceptional pollen source — the catkins shed enormous quantities — and a good nectar source in the right weather. The pollen arrives at a useful moment for colonies building towards late summer.
• SageVery high nectar and only moderate pollen — sage feeds adult foragers superbly and contributes comparatively little to brood rearing, which is a common pattern in the mint family.
• MintGood nectar at a genuinely useful point in the season. Its value is timing and reliability rather than volume.
• MarjoramRepeatedly ranks at or near the top of controlled garden trials for total insect visits, and unusually it scores well for both bees and butterflies — few plants do both.
• ComfreyExceptional nectar, but genuinely restricted by flower shape — which is why the separate rating for accessibility matters more here than almost anywhere else.
• BuddleiaThe separate ratings do real work here. Buddleia offers substantial nectar and very little accessible pollen, so it feeds adult insects and contributes almost nothing to raising the next generation of bees. A garden of nothing but buddleia would starve its own pollinators.
• HoneysuckleHigh nectar, and largely unavailable to bees. The ratings and the accessibility note have to be read together here or the plant looks far better than it is for the insects most people are planting for.