Why a wildflower meadow earns its keep

A patch of native wildflowers is one of the most generous things you can give your garden. Unlike a bedding display that flowers for a fortnight and then sulks, a meadow mix keeps going from late spring into autumn, offering pollen and nectar when pollinators need it most. Just as importantly, it hands over a harvest of seeds in late summer and autumn, which is precisely when seed-eating birds such as goldfinches, linnets and greenfinches are looking for a natural larder.

The other appeal is that a meadow is genuinely low-maintenance once it is established. You mow it once a year, at the right time, and that is more or less that. The catch is that "wildflower meadow" is not one recipe. Get the seed mix wrong for your soil and you will spend two seasons watching a lush green carpet of grass with a few sad ox-eye daisies in it. Get it right and the same patch will hum from June onwards.

Match the mix to your soil before you buy a single seed

Wildflowers fall into two broad camps, and the distinction matters more than anything else in this article.

• Annuals and short-lived species — corncockle, cornflower, poppies, corn marigold. These are the cornfield flowers, and they want disturbed, fertile ground. They are brilliant for a quick, colourful first year, but they fade unless the soil is broken up annually.
• Perennial meadow species — ox-eye daisy, knapweed, meadow buttercup, yellow rattle, birdsfoot trefoil, selfheal, yarrow. These are the long-term backbone of a meadow and they thrive on poorer, leaner ground.

Now test your soil honestly. If it is heavy clay, rich loam, or you have been feeding a lawn on it for years, it is too fertile for most perennial meadow flowers. Grasses will simply outcompete them. Your options are to strip the topsoil, to grow a few years of hungry crops to draw nutrients out, or to accept a mix with a higher proportion of robust species such as ox-eye daisy and knapweed. On sandy, stony or chalky ground you are in luck — perennial meadow mixes tend to establish readily.

Buy seed of British native origin rather than a cheap general-purpose mix, and check the percentage of wildflower to grass. A genuine meadow mix is often 80 per cent grass and 20 per cent flowers by weight, and that is fine, provided the grass species are fine-leaved ones like crested dogstail, sheep's fescue and bent, not agricultural ryegrass.

Sowing: preparation is nine-tenths of the job

Clear the ground of existing vegetation completely. Perennial weeds such as couch grass, dock and thistle will otherwise haunt you for years. Either strip the turf with a spade, or smother the area with cardboard and a thick mulch for a full growing season before sowing.

Once cleared, rake the surface to a fine, firm tilth. Sow in either early autumn (September to mid-October) or early spring (March to April). Autumn is generally better because the soil is still warm, rain does the watering for you, and the plants get a head start on the following spring.

Mix the seed with dry sand or fine silver sand at roughly ten parts sand to one part seed. This bulks it out so you can see where you have been and spread it evenly by hand, in two passes at right angles to one another. Then firm it in — walk over it or roll it — so the seed makes good contact with the soil. Do not bury it. Wildflower seed needs light to germinate, so a very thin scatter of soil or none at all is correct.

Water only if the weather turns dry in the fortnight after sowing. After that, leave it alone. Do not feed it, ever.

Yellow rattle: the secret weapon

If there is one plant to single out, it is yellow rattle. This native annual is semi-parasitic on grasses, tapping into their roots and weakening them. That opens up space for the flowers. Sowing yellow rattle into an existing grassy patch is one of the most effective ways to convert a lawn into a meadow, and it is the reason conservationists swear by it.

Sow it in autumn, ideally alongside your flower mix. It needs a period of cold to germinate, so spring sowing is far less reliable. Once it is in, let it set seed before you cut — its dry rattling seed heads in July are your signal that it is ready.

Mowing once, and making that cut count

This is where most people go wrong, usually with the best of intentions. A meadow should not be cut regularly through the summer. If you mow it in June, you remove the flowers just as pollinators need them, and you never let the plants set seed for the birds.

The rule of thumb is simple. Cut once, late in the season, from late July through to September depending on your site and how the seed heads are looking. On lighter soils the meadow often finishes earlier; on heavier, damper ground it can run into September.

When you cut:

• Set the mower high for the first pass, then lower for a second pass a few days later to tidy up.
• Remove the cuttings. This is essential. Leaving them to rot returns nutrients to the soil and encourages the grasses you have spent two years suppressing. Rake them up and add them to the compost heap.
• Leave a few uncut patches, or a strip along a hedge, over winter. Seed heads standing through the cold months feed birds and shelter overwintering insects.
• If you want a succession of flowers, cut half the meadow in late summer and the other half in early spring. You will get a longer flowering season overall.

Expect the first year to look modest — some annuals, a lot of green. Year two is usually better. By year three or four, with yellow rattle working away and annual cuts removing nutrients, the flowers begin to hold their own against the grass. From then on, the meadow is largely self-sustaining, and the bees, butterflies and finches will tell you it was worth the wait.