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Why Trees Are the Backbone of a Pollinator Garden

When gardeners think of bee-friendly planting, they usually picture a border of lavender, foxgloves and catmint. All excellent choices — but a single mature lime or willow will produce far more nectar and pollen than the whole border put together. Trees and large shrubs offer pollinators something a perennial bed struggles to match: sheer volume of bloom, held high above the ground, opening at exactly the moment insects emerge and run short of food.

They give structure, shade, autumn colour and nesting sites, and most need little more than a generous planting hole and a couple of years of careful watering. Get the species right and you will be feeding bumblebees in February, honeybees in June and red admirals in October.

Early Spring: Feeding Bees When Little Else Is in Flower

Queen bumblebees wake from hibernation hungry, often in the first mild week of March, and early solitary bees follow soon after. This is the hardest time of year for them, and the trees that help most are those with catkins and early blossom.

• Goat willow (Salix caprea) — the single best early source of both pollen and nectar. Male trees carry fat, silvery-yellow catkins in March and April. It suits damp ground and can be coppiced every few years to keep it shrubby.
• Blackthorn (Prunus spinosa) — clouds of white blossom before the leaves appear, ideal for a native hedge on heavy clay.
• Hazel (Corylus avellana) — pollen-rich catkins from January, plus nuts for squirrels and dormice.
• Field maple (Acer campestre) — modest flowers in April, and its aphids later produce honeydew that bees adore.

Aim to plant these where the early sun reaches them. A willow or blackthorn in deep shade will flower late and sparsely, wasting its potential.

Late Spring and Early Summer: The Main Flow

From late April into June, fruit and hedgerow trees take over. This is the period when colonies are building and demand is at its peak.

• Crab apple (Malus sylvestris) — generous blossom in May, followed by fruit for blackbirds. Choose a single, simple-flowered variety; double blossoms are sterile and offer nothing.
• Wild cherry and bird cherry (Prunus avium, P. padus) — masses of nectar in April and May.
• Hawthorn (Crataegus monogyna) — the backbone of a British hedgerow, flowering May to June and feeding moths and birds later.
• Rowan (Sorbus aucuparia) — compact enough for a small garden, with spring nectar and autumn berries.
• Holly (Ilex aquifolium) — small, inconspicuous flowers in May and June that bees work enthusiastically. You need both a male and a female for berries.

If you have room for only one large tree, plant a small-leaved lime (Tilia cordata). Its June and July flowers drip with nectar and are among the finest bee trees in Europe. Be warned: it is a big tree, so give it space or choose a grafted compact form.

High Summer: Keeping Nectar Coming

Mid-summer can be a lull. Many spring trees are finished, and bees must travel further. Fill the gap with generous shrubs, which do the same job on a smaller scale.

• Buddleia (Buddleja davidii) — prune hard in March to keep it flowering into September. Deadhead to extend the season.
• Escallonia and ceanothus — both excellent for butterflies and bees in coastal and mild gardens.
• Cotoneaster, berberis and spiraea — unfussy shrubs that flower reliably and berry well.
• Rosemary, lavender and shrubby honeysuckle — perfect along a sunny path or at the front of a border.

Plant these in groups of three or more rather than singly. A pollinator flying across a garden navigates by sight, and a decent-sized patch of one flower is far easier to find than scattered singles.

Autumn and Winter: Ivy, Berries and Shelter

As the days shorten, a handful of plants become lifelines. Common ivy (Hedera helix) is the most important. Its greenish flowers open from September to November, precisely when queen bumblebees are fattening up for hibernation and late butterflies are still on the wing. Leave mature ivy alone until February, when the berries have been eaten by thrushes, then cut it back if it is swamping a wall.

Berry-bearing trees — rowan, hawthorn, holly, crab apple and cherry — carry the garden through winter for birds, while evergreens such as holly, yew and laurel give shelter and hibernation cover for insects. A log pile at the base of the hedge and a patch of undisturbed leaf litter multiply the benefit tenfold.

Planting, Spacing and Aftercare

Bare-root trees, planted between November and March while dormant, establish faster and cost far less than potted stock. Choose a day when the ground is not frozen or waterlogged.

• Dig a square hole three times the width of the roots and no deeper than the nursery mark on the trunk.
• Firm the soil in layers, then water well — even in winter.
• Mulch with 5–7cm of bark chippings, keeping it clear of the trunk to avoid rot.
• Water deeply once a week through the first two summers. Little and often is worse than useless.
• Stake only if the site is windy, and remove the tie after two or three years.

For hedges, plant at 30–45cm spacing in a double staggered row and lay or trim on a three-year rotation so there is always flowering wood. Prune flowering shrubs straight after they finish, never in spring, or you will cut off the very buds the insects came for. Avoid double-flowered and variegated forms almost everywhere — they look handsome but give pollinators nothing to eat.

Finally, resist the urge to tidy. Leave aphids alone, let dandelions and clover flower in the lawn, and skip the insecticide entirely. A garden that hums is not an untidy one — it is a working one.