How to save seed
by Drucilla James
Take care- saving your own seed is likely to become addictive- especially as you can collect seeds from almost all your garden plants to create brightly coloured borders or delicious vegetable plots. You will need to be selective and avoid growing plants that don’t earn their places at the expense of much more deserving and rewarding ones.
There are lots of advantages to collecting and saving your own seed:
(1) You can harvest the seed of those plants you treasure, secure their stock for the future and save money at the same time.
(2) You will have the excitement of seeing the wonderful results from seed you have collected and planted
(3) There will be seed to share or swap with friends and neighbours or to donate to organisations such as the Hardy Plant Society www.hardy-plant.org.uk and request seed in return.
Most plants set seed but be warned that not all plants produce seed that when planted will come true and give you the plant you started with. A rough guide is to go for plants that have a Latin Genus name and a Latin Species name, i.e. pure species plants. Avoid highly bred hybrids – any plant that is an F1 or a variety will not come true.
Things you’ll need
(1) Paper bags/old envelopes with holes strategically punched to allow air circulation.
(2) Paper, newspaper or kitchen towel.
(3) Trays, clean margarine tub lids or shoe box lids etc
(4) Kilner jars with rubber seals in good condition
(5) Sieves – those specifically for this process are expensive (£40 each) so a range of metal kitchen sieves with different size holes will suffice.
(6) Silica gel crystals- you can save those that come as packaging.
(1) Seed heads tend to turn brown or straw-coloured and papery thin when they are ripe. It is essential to keep checking the seed heads when they get close to maturity as they will suddenly shed their seed. Particularly on still, dry, warm days they change very quickly (lots of seeds scatter under these conditions). This is the best time to collect in order to save drying time.
(2) For fine seed, select the best flower/seed head; cut the whole thing off; place in a paper bag and shake it-this will give you plenty of seed. If the seed head is too large for any bag you have then fold newspaper sheets to form a container. For large seeds you can collect seed by hand or in some cases as large seed pods.
(3) Explosive seed heads are a little more challenging (Viola, Euphorbia, broom, hardy geranium). Choose a seed head, cut off the whole head and put it into a paper bag, tie the neck firmly and put in a hot dry place and wait. The head will soon explode if ripe. Alternatively tie a paper bag around the seed head and wait.
Cleaning the seed
The aim of the next stage is to prevent deterioration. The seed now needs to be cleaned. Remove all the debris as this harbours pests and diseases; remove the larger bits by hand or you can sieve them out. As seeds are so diverse the amount and type of debris is very variable. Lay larger seeds in the palm of your hand and gently pull away larger bits of debris or roll them back and forward under the first two fingers and gently blow away chaff. Fine seeds separated from their seed case can have the debris carefully removed by very gently blowing over them. This has to be well controlled or the seed will disappear too!
Drying and storing the seed
To store the seed successfully it needs to be dried further, as in warm damp conditions it rapidly decays and rots, destroyed by mould. Lay the seeds on paper or on margarine lids, or in used tissue boxes in a warm dry location (best below 50% humidity) for a week to ten days. Do not put in an oven or in direct sunlight, especially pods like sweet peas, peas and beans as seeds need to dry naturally. The more slowly the seed is dried out the better the eventual germination will be; every 5C drop in temperature of the storage environment will double the life of the seeds.
Once dried, pack seeds into LABELLED paper seed envelopes/bags and store these in a Kilner jar (excellent for storing seeds as they form an air tight seal as long as the rubber seal has not perished). A sachet of a drying agent such as silica gel, hot baked rice (see Real Seeds at www.realseeds.co.uk) put in the jar will keep the air moisture-free. Store the jar in a cool dark place and the seeds will remain viable for at least three years.
Some seed needs to be sown fresh. For example with hardy cyclamen, a bag needs to be tied around a capsule as soon as it starts to split to capture all the seed. The seed then needs to be soaked for twenty four hours and sown as soon as possible.
Some flowering plants to try
It is advisable to limit yourself a little during your first year and focus on your absolute favourites and some rarer specimens.
Verbascum, Dianthus, sweet william,Primula, foxglove, Meconopsis, lupin, hollyhock, Lychnis, poppy,Geum “Mrs Bradshaw” a named variety but unusual in that it comes true,Aquilegia
Petunia hybrida, Anthirrinum, Lathrys odorata,Tagetes signata
Alpines and rock garden plants
Lewisia,Primula, Aubretia, Gentian,Alyssum saxatile
Saving seed from fleshy fruits
Berries, drupes etc should be stored in open containers in cold, humid conditions such as a fridge. They need to be kept moist so they neither shrivel nor rot.
(1) Separate the seed from the debris. Some fruits can be left to dry completely and smashed with a hammer eg rose hips. With others, you can macerate the fruit by hand or use a kitchen masher- a blender can also be used but care has to be taken not to destroy the seed so blunt blades are best.
(2) Gradually add water to the mashing so the seeds separate out from the fruit pulp. The most viable seeds will sink to the bottom so you can discard any that float to the top. Pour off most of the water leaving the seeds behind. Repeat the sequence until you have clean seeds remaining.
(3) Dry the seeds by placing them on two sheets of paper. Keep them in a cool dry place for one to two weeks, regularly changing the sheets of paper.
(4) When completely dry the seeds can be put in packets and labelled.
Saving seed from vegetables
All the detailed information you could need to deal with vegetables can be found at www.gardenorganic.org.uk Heritage Seed Library.
However some advice on common vegetables is as follows:
Carrot: Keep seed from the best umbel (seed head) usually the primary umbel from the healthiest plant as this produces better quality seed. Dry the seed in air that is warm and of low humidity for one week.
Tomato: These seeds need to be removed from their surrounding gel as this contains abscissic acid which inhibits germination. To do this push the seeds through sieves of reducing size. Alternatively the seeds can be dropped into a jar of water (a few soda crystals makes this work more quickly) and left to soak to leach out the acid. Seeds which float to the surface should be discarded. The seeds from the bottom of the jar should be placed on the lid of a margarine tub to dry off slowly.
Peppers and Chillis: Plants you want to breed true should be kept 9 metres apart-so in a small urban garden keep to a few plants in pots at each end of the garden.
Lettuce: Check carefully you are taking fully mature seed. Shake the head into a bag and dry. Salad bowl varieties are easier than iceberg types where the leaves have to be stripped off to a stump to allow the flower head to form.
Peas and sweet peas: Pods should be left to mature, then the peas removed from the pod and dried. Drop these into water at 100C for 3 seconds only before planting the following season.
Radish: These form decorative long pointed pods that turn pale brown. To harvest break open a pod, check the seeds are brown, then dry them and store in packets in a Kilner jar.
Broad beans:Collect pods and wait until they go black, then remove seeds, dry them and save in a Kilner jar. Rats enjoy these plants and will take whole pods so if this is a problem remove the whole plant and hang upside down to dry.
Onions: Remove the ball-shaped seed head before the stem collapses. Cut it off and dry it, shake the mature seed head into a paper bag and dry the seeds and store.
Brassicas: are difficult to get true seed from so for the amateur gardener it is more worthwhile to buy new each season.
Images courtesy of RHS