16 February 2015
Many garden centres and catalogues these days have fancy seed storage containers for sale, possibly to give as presents due to their attractive appearance. These are obviously a waste of time unless you have some seed to save, and instead of buying seed, why not save some of your own.
Seed can be saved from all sorts of plants and trees, though the most popular are likely to be from vegetables and flowering plants. There are a few things to bear in mind though when harvesting your seed.
Seedheads often ripen quickly, and must be watched carefully so that you can collect the seeds before they are dispersed. Seed is usually set about two months after flowering. Seed from ranunculus, calendula and anemone nemorosa, for example, should be collected when well developed but immature and green.
You will need to collect berries before the birds have them.
Good quality seedlings and plants will come from seed taken from vigorous, healthy plants. Most seed germinates best if sown as soon as it has ripened, while seed sown before reaching maturity will not germinate. Usually only species “come true” from seed, while seedlings from a hybrid will be extremely variable.
Nature has devised many different types of seed packaging, with the most common forms including
Capsules (e.g. poppy)
Pods (e.g. sweet peas)
Berries (e.g. holly)
Catkins (e.g. birch)
Nuts (e.g. hazel)
Winged seed (e.g. Acer, sycamore)
Exploding seedheads (e.g. Euphorbia lathyrus)
Collect ripe seed on a dry day, as soon as the seedheads ripen - which is often indicated by a change in colour - but before they open and shed their contents.
Pick the seedheads, either singly or on stalks, and lay them out to dry somewhere warm. This makes it easier to extract the seed. If the seedheads don’t open when dry, gently crush them to release the seed.
Collect seed from fleshy fruits and berries by mashing them in a fine sieve and then rinsing away the pulp in cold water. Leave the seed to dry for a few days on paper towels.
Exploding seedheads need to be checked every few days. Either place a paper bag over them and shake – this will usually cause the ripe seedheads to explode into the bag - or alternatively, remove the seedheads on their stems as they turn brown and place in a labelled paper bag.
Nuts need to be collected around the time they would naturally fall, either by hand-picking or by placing a sheet at the base of the tree and shaking the branches until they fall.
After extracting the seed, clean off any surrounding material attached to them, as this can often harbour pests and diseases and lead to the seed damping off.
You will usually need to store your seed until the correct time of year for sowing, though some seed such as hellebore is best sown immediately as its viability reduces with storage.
Place dry seed in labelled paper packets in an airtight container with a desiccant, such as silica gel, to remove excess moisture. Excess humidity or warmth can cause seed to deteriorate or die from rotting or fungal disease.
Some seed, such as walnuts, oaks and magnolias, however must not be allowed to dry out as they cannot then take up water necessary for germination. These seeds can be stored for several months in a plastic bag of damp vermiculite, sand, or a mix of moist coir and sand.
If kept in a fridge at 5°C, most seed will remain viable for many years.
The one thing better than growing your own is to grow your own from your own seeds. Good luck!