Why grow wildflowers in pots at all?

If you have a balcony, a back yard the size of a bath mat, or a north-facing windowsill, you might assume wildflowers are out of reach. They aren't. A well-planted container of British natives is one of the best things you can do for urban pollinators, and it takes far less space than people imagine. Three decent-sized pots on a sunny step will pull in bees, hoverflies and the occasional butterfly that would otherwise have to travel to the nearest hedgerow or railway embankment to feed. You also get the pleasure of watching cornfield flowers you'd rarely see in the wild now, since many are clinging on only in field margins.

The trick is to stop treating them like bedding plants. Wildflowers want lean, free-draining ground, no feeding, and a bit of tough love. Get that right and they largely look after themselves.

Three natives worth starting with

Cornflower, oxeye daisy and birds-foot trefoil make an excellent trio: they flower in succession, suit containers, and between them feed a wide range of insects.

• Cornflower (Centaurea cyanus) – a hardy annual with that unmistakable blue. Sow it in March or April for flowers from June, or in late August for a head start the following spring. It reaches 60–90cm, so give it a pot at least 30cm deep. Bees and butterflies adore it, and goldfinches will take the seed later.
• Oxeye daisy (Leucanthemum vulgare) – a dependable perennial that forms a clump and throws up 45–60cm stems from June to September. Once established it shrugs off drought better than almost anything else in a pot, and hoverflies, small beetles and solitary bees all use it.
• Birds-foot trefoil (Lotus corniculatus) – low, scrambling and brilliant for a shallow trough or the front of a mixed pot. It's the larval food plant for the common blue butterfly and several day-flying moths, and as a legume it quietly fixes nitrogen. It flowers best on poor, gritty ground, so be mean with it.

If you have room for a fourth pot, add yarrow, selfheal or wild marjoram. All are easy from seed and all are hedgerow regulars.

Peat-free compost and the right container

Use a peat-free multipurpose compost, but don't plant into it neat. Wildflowers sown into rich compost grow soft, flop about and flower poorly. Mix roughly three parts peat-free compost to one part horticultural grit or sharp sand, which opens up the texture and mimics the thin, stony soils these plants evolved on. A handful of leafmould is fine; a handful of general-purpose feed is not.

For containers, bigger is genuinely better. A 35–40cm diameter pot holds enough root run and moisture to survive a hot week, whereas a 15cm pot will need watering twice a day by July. Terracotta dries out fast, glazed pots hold moisture longer, and a repurposed trug or old bucket works perfectly well provided you drill drainage holes. Raise pots onto feet so water can escape, and skip the saucer in summer — wildflowers hate sitting wet.

Sowing and the first season

Fill your pot, firm gently, and scatter seed thinly across the surface. For a 35cm pot, a pinch of each species is plenty; overcrowding is the single most common mistake, and thinning seedlings feels brutal but pays off handsomely. Cover with 3–5mm of compost and water with a fine rose rather than a jug, which would wash the seed into one corner.

Keep the surface damp until germination, usually 10–21 days. After that, water only when the top couple of centimetres are dry — a finger poked in is a better gauge than a schedule. From midsummer onwards, established plants need water perhaps twice a week in dry spells and nothing at all after rain. Never feed them.

Cutting back, seeding and winter

Deadhead cornflowers through summer to keep them going, but leave the last flowers to set seed — shake the heads over the pot in September and you'll get volunteers next spring. Cut oxeye daisies back to about 10cm after their first flush and many will reward you with a second, smaller showing in late summer.

Resist the urge to tidy everything in autumn. Hollow stems and dried seedheads are winter shelter for ladybirds, lacewings and small solitary bees, and the seed is food for birds. Leave the lot standing until late February or March, then cut back to just above the new growth and top-dress with a little grit.

Small pots, big hedgerow connections

A container garden won't replace a hedgerow, but it can act as a stepping stone between them. Bees foraging your oxeye daisies will also work the hawthorn and blackthorn nearby; the trefoil in your trough may support common blues that breed on the verge down the road. Add a shallow dish of water with a few pebbles for drinking, and you've made a genuinely useful little habitat. Start with one pot this spring, and you'll find room for three more by next.