Best Annuals and Biennials for a Bee Garden (UK)

Garden centres sell annuals and biennials by colour and flower size, not by nectar content, and the two are often at odds. Many popular bedding plants have been bred for double or semi-double flowers — extra petals formed from what would otherwise be the reproductive parts of the flower. A double marigold or double zinnia can look spectacular and offer a bee almost nothing, because the stamens and nectaries have been bred away to make room for petals. If you want a garden that actually supports bees rather than just looking bee-friendly, the rule of thumb is: buy single-flowered, open-centred forms wherever a choice exists, and check that you can actually see the central disc of stamens.

Annuals and biennials matter more than their short lifespan suggests. Because they're sown or planted fresh each year (or grown from seed the year before flowering, in the case of biennials), they're the easiest way to plug seasonal gaps in a border — especially the late-summer dip after early perennials finish and before autumn-flowering plants take over.

Foxgloves (Digitalis purpurea) are one of the best early-summer plants for long-tongued bumblebees. The tubular flowers are shaped almost exactly to fit a bumblebee's body — you can watch the bee disappear entirely into the flower to reach the nectar at the base, picking up pollen on its back as it goes. Common purple foxglove, our native form, is more valuable to bees than some of the newer compact or multi-coloured strains, which can have distorted or upward-facing flowers that are harder for bees to access. Foxgloves are biennial (leaves in year one, flower spike in year two) and self-seed readily in part shade, making them ideal for woodland-edge or shady border spots where fewer good bee plants thrive.

Hollyhocks (Alcea rosea) produce large, open, single flowers loved by bumblebees and by hairy-footed flower bees and other solitary bees, which will burrow right into the flower for pollen. As with other bedding classics, avoid the fully double ‘powder puff’ hollyhock cultivars — they're bred for show and carry little accessible pollen. Hollyhocks are prone to rust disease in damp UK summers; this doesn't affect their bee value but does affect how tidy they look, so plant something in front to hide lower leaves.

Sweet rocket (Hesperis matronalis), also called dame's violet, is a much underused biennial — clouds of scented lilac or white four-petalled flowers in late spring, right in the gap between spring bulbs finishing and early-summer perennials starting. It's especially valuable to bees and moths because it flowers into the evening and is strongly scented, and it self-seeds freely once established, effectively becoming a permanent feature from a single sowing.

• Sunflowers (Helianthus annuus) — choose single-flowered, pollen-producing varieties. Many modern branching sunflower varieties are bred pollen-free for the cut-flower trade so they don't shed on tablecloths; these are decorative but worthless to bees. Look for seed packets that say 'pollen-producing' or stick to open-pollinated heritage types. A single large sunflower head can host dozens of bee visits a day at peak flowering.
• Cosmos (Cosmos bipinnatus) — reliably single-flowered as commonly sold, easy from seed, flowers non-stop from midsummer to first frost if deadheaded, and popular with bumblebees and hoverflies. One of the best value-for-effort annuals for a new gardener.
• Zinnias — good for bees and butterflies when single or semi-double, but the many “cactus-flowered” and fully double zinnia strains sold for cutting gardens are far less useful; check the flower centre before buying.
• Marigolds (Tagetes and Calendula) — pot marigold (Calendula officinalis) is a genuinely useful, easy, edible-flowered annual with an open centre bees can use; French and African Tagetes marigolds are mostly grown for companion-planting pest control and their tightly packed double flowers offer little to bees, so don't count on them as a forage plant even though they're marketed alongside “pollinator” seed mixes.
• Alyssum (Lobularia maritima) — small, but do not underestimate it. Sweet alyssum produces huge numbers of tiny, easily accessed flowers over a long season and is a favourite of small solitary bees and hoverflies as well as bumblebees; it's an excellent edging or gap-filler plant for exactly the pollinators that struggle with larger, deep flowers.

Most of these annuals are best direct-sown or planted out after the last UK frost (typically mid-to-late May outside the mildest areas), and many, including cosmos and sweet alyssum, will flower for longer if deadheaded regularly rather than being left to set seed early. Foxgloves, hollyhocks and sweet rocket are biennial, so sow them by midsummer of the year before you want flowers — a common mistake is sowing biennials in spring expecting flowers the same year, which mostly doesn't happen. Group plants in blocks of the same species rather than dotting single plants around; bees forage more efficiently, and expend less energy, visiting many flowers of one kind in succession (a behaviour called flower constancy) than hopping between scattered singles.