Why a sowing calendar matters more in a wildlife garden

Most gardening calendars are written for flowers. Ours is written for the birds, bees and butterflies that use them. In a wildlife garden the point of a flower is not just the bloom, but the whole life of the plant: the nectar it offers in July, the seed heads it holds through November, the stems that stay standing for insects to overwinter inside, and the ground it covers for foraging blackbirds in January.

That changes the timing. If everything bursts into flower in the same three weeks of June, your garden feeds wildlife lavishly and then goes quiet. A simple sowing calendar spreads the harvest. It is not complicated, and it does not need a greenhouse, a heated propagator or any great expense. A few packets of hardy annuals, a patch of bare earth and a little patience will do most of the work.

Below is the calendar I use, adapted from years of growing on heavy clay in a windy corner of the Midlands. Adjust the dates by a fortnight either way depending on whether you garden in Cornwall or Caithness.

Early spring: hardy annuals sown where they are to flower

Hardy annuals are the backbone of a bird-friendly border. They germinate in cool soil, tolerate a late frost and flower within twelve to fourteen weeks of sowing. That means a sowing in late March or early April gives you nectar through July and August, followed by seed heads into autumn.

From mid-March, once the soil has dried enough to crumble rather than clag, sow directly into a prepared seed bed. Rake the surface to a fine tilth, water the drill before sowing rather than after, and cover the seed lightly. Birds are excellent at finding seeds, so a scattering of twiggy prunings over the row is worth the effort.

Reliable choices for wildlife:

• Cornflower and corn marigold for bees and finches, sown in a sunny spot.
• Borage, which flowers for months and is mobbed by bumblebees.
• Calendula and pot marigold, generous with nectar and easy to save seed from.
• Nigella, whose papery seed pods feed goldfinches in late summer.
• Sunflower, sown in late April once the soil has warmed, for a seed harvest in September.

Thin the seedlings to about 20cm apart. Crowded plants flower poorly and set little seed. If slugs are a problem, a clear ring of dry soil around each seedling helps more than pellets.

Late spring: filling the gap before the main flush

There is often a lull in May and early June when spring blossom has finished and the annuals have not yet opened. Sowing a fast, short-lived annual in late April bridges it neatly.

Good options include phacelia, which flowers six to eight weeks from sowing and is one of the best nectar plants for hoverflies and bees, and corn poppy, sown on disturbed ground where it will self-seed happily thereafter. Both will grow in poor soil, which is exactly what you want in a wildlife patch: rich soil makes leafy plants and few flowers.

If you have a spare corner, leave a patch of ground unplanted and simply scuffle it with a rake in April. Many of our best wildflowers, including poppies, scarlet pimpernel and fat hen, will appear on their own. Fat hen seeds feed house sparrows and greenfinches through the winter.

Summer: biennials for next year, and a second sowing for autumn

Biennials are the quiet heroes of a wildlife garden. Sown in June or July, they spend the rest of the year building roots and a rosette of leaves, then flower the following spring and summer when there is precious little else about.

Sow biennials in trays or a nursery bed in June and July, keeping them watered through any dry spell. Plant them out in early autumn so they establish before the cold. The list that earns its place:

• Foxglove, unbeatable for bumblebees and a favourite perch for small birds.
• Honesty, with purple flowers in spring and translucent seed discs that last into winter.
• Teasel, whose spiny heads hold seed well into the new year and attract goldfinches.
• Evening primrose, opening at dusk for moths.
• Sweet William and wallflower, both generous with nectar in early summer.

At the same time, make a second sowing of hardy annuals in late June or early July. These will flower from late August into October, exactly when birds are fattening up for winter and bees are still foraging. Calendula, cornflower and nigella all work well. Water the seedlings through dry weather until they are established.

Autumn: leave the seed heads standing

The most important job in autumn is doing nothing. Resist the urge to cut back. Seed heads on teasel, sunflower, nigella, honesty and cornflower are a winter larder for goldfinches, greenfinches and siskins, and the hollow stems of larger perennials shelter overwintering insects.

Cut back only what has collapsed and gone soggy, and leave the rest until late February or March. If you want to tidy, cut stems into short lengths and stack them in a corner rather than putting them in the green bin.

This is also the moment to collect seed from your best plants. Let the heads dry on the plant, then tip them into a paper envelope and store somewhere cool and dry. You will need less than you think; a pinch of seed goes a long way, and the rest can be scattered where you want it.

Succession sowing through the year

The principle behind all of this is succession. Sow small amounts often, rather than everything at once, and your garden will hold nectar and seed from April to November. A rough plan might look like this:

• March: hardy annuals for summer flowers.
• April: phacelia and poppies for the early-summer gap; sunflowers for autumn seed.
• June and July: biennials for next year, plus a second sowing of hardy annuals for autumn flowers.
• August: a final quick sowing of cornflower or calendula for late colour, if you have water to spare.
• September onwards: leave seed heads, collect seed, and let the garden feed the birds.

Nothing here requires special equipment or a perfect plot. A border edge, a strip beside a hedge or a few containers on a patio will all work. Sow a little, often, and let the plants finish their job. The birds will notice long before you do.