Collect and grow your own seeds for wildlife

Dandelion demonstrating its beautiful seeds designed to catch the wind, Image by Rowena Millar

Rowena Millar, Cornwall Wildlife Trust's (currently Non-Roving) Wildlife Reporter, continues to show us how to make the best of our gardens for wildlife. This week, Rowena shares how to add colour and life to our gardens through seed gathering and planting... all for free!

Walking around the garden in August, I’ve been noticing fascinating and varied seed capsules forming, as once-beautiful flowers fade and shrivel away. Most of these can be left for the seeds inside to self-sow, or be eaten and/or dispersed by birds and other creatures, or simply to look ornamental. But also, for us wildlife gardeners, it’s seed-gathering time!

To enhance your wildlife garden for free, collecting and sowing your own seeds is a rewarding experience, both for you and for next year’s wildlife, especially pollinating insects.

Your annual garden plants such as sunflowers, forget-me-nots, teasels, Love-in-a Mist – and a host of meadow flowers – release their seeds at the end of the season and then die down forever, relying on the next generation to grow from seed ready for the following year. Many of their seeds won’t ever reach a patch of fertile, bare soil where they can germinate.

You can improve their prospects by gathering some of the seeds from any dry, brown, mature-looking seed capsules. You can then either sow them immediately in trays or store them, ready for sowing next spring.

Seeds that fall away from the plant easily are ready to be collected. Wind-dispersed seeds, such as those of knapweeds, are likely to be found at the bottom of the seed head rather than the top, which is adapted to catch the wind and float like a feathery parachute.

Remember, there are herbaceous perennials (and biennials), such as the geraniums/cranesbills that also seem to have died down like the annuals, but they reappear the following year, sprouting up from roots that survive the winter. I collect seeds from these too, to help them spread more quickly around the garden and create lovely clumps and patches of particular flower colours and shapes. Clumps and drifts, rather than isolated single specimens, will support more of the particular kinds of insects that appreciate them.

Under the Wildlife and Countryside Act, it is legal to collect seeds from meadows or hedges, as long as you don’t remove or uproot the whole plant. This means that you can go out and collect a few seeds from native species that you would like to add to your garden.

A bed of wildflowers near Saltash, East Cornwall

A bed of wildflowers near Saltash, East Cornwall, Image by Rowena Millar

How to collect seeds

The best way to collect seeds is to have some paper bags or paper envelopes ready. Break off one or more seed heads and let them fall into the open bag or envelope: capsule, seeds and all. Later, you can remove the capsules of each species ready for sowing or storage of their contents (the seeds can disperse better and will be less likely to rot if outer capsules are removed). Remember to label each bag or envelope with the correct species name. I have often forgotten to do this and hardly ever remember what I collected. You can sort your seeds on white paper, to see if they are plump and viable-looking or shrivelled up, in which case they may not have been fertilized and won’t germinate.

For detailed information on seed storage, this is a useful video to watch:

Video by Yorkshire Dales Millenium Trust

How to sow and grow your seeds

In general, meadow wildflowers grow on poor soils where they will not be outcompeted by strong grasses. So in a reasonably shallow tray with drainage holes, create a seedbed that isn’t too rich. Your planting medium should be light and porous, such as sieved soil-based garden compost (don’t use peat for conservation reasons), perhaps with added perlite, grit or horticultural sand for air and drainage.

If you are growing bog or riverside plants (such as Meadowsweet, Marsh Marigold or Devil’s-bit Scabious), consider making a soggier planting compost. Make a note of each habitat your plant prefers and try to recreate the ideal conditions.  

A few species germinate better if they are scarified (rubbed gently between pieces of sandpaper), as they usually start to grow after a long period of being scratched about in the ground. Vetches, trefoils and cranesbills fall into this category, but my own cranesbills have germinated well without being scarified.

Large seeds do best as plug plants in modules, where their roots have plenty of space to grow downwards. If you don’t have old plastic modules or pots to reuse, you can try old drinks cartons or yoghurt pots with holes in the bottom, or toilet roll middles, or handmade newspaper pots (instructions can be found online).

Fill your tray or module three-quarters full, firmed gently, then sprinkle on the seeds, not too thickly. Small seeds from meadows need only the very lightest dusting of a covering. Many meadow plants, such as poppies, require light and air for their seeds to germinate. The larger the seed, the more space it might need.

Label each tray with the species and sowing date. When large enough, you can pot on each seedling into a larger container with more soil, so it can grow a larger rootball. Dig it up and separate it from its neighbours very gently, maybe using a thin stick or plant label as a trowel. Hold it by its leaf or root, rather than squashing delicate stems. Plant your seedlings out or pot them on when you can see the roots starting to come out of the bottom of the pot, and make enough space for them to survive amongst taller plants as they grow bigger and stronger.

Seed Capsule Shapes

Seed capsule shapes in the garden, Image by Rowena Millar

When to sow and grow your seeds

Both annuals and perennials can be sown either in late summer/early autumn or in spring. Seeds to sow in August include calendulas, cornflowers, forget-me-nots, and Wild Carrot (Queen Anne’s Lace). Perennials may be harder to grow initially, but you won’t have to keep planting them from seed each year.

You might like to cultivate some annual Yellow Rattle from seed. This flowering plant weakens strong grasses by taking the nutrients from their roots, giving wildflower species a chance to grow, and it is also rather pretty.

Some plants, including Yellow Rattle and Primrose, need a period of cold weather before their seeds will germinate, so you can sow them in pots or seed trays then leave them outside for the winter. Some seeds tend to rot in wet weather and these are better stored in quite dry, cool conditions then planted from mid-March.

For me, when and how to grow seeds and seedlings of wildflower species in the garden is an ongoing case of trial and error … you too can have fun experimenting to see what grows best at what time in your particular weather and soil conditions.

Have fun experimenting to see what grows best at what time!

If you are short of space, you can make a small meadow or garden in a container (see the how to create a container garden for wildlife page). 

Whatever you do, scattering seed onto thickly growing, established grass won’t work. It is better either to start from scratch on bare earth (see how to grow a wild patch - there is more information in Option 2) or use the method described above of nurturing plants from seed in trays or pots and inserting them into the garden when they are strong enough to hold their own.

Whatever you do, you too can bring colour and life to your garden next year for free.

More information on wildlife gardening