Most gardeners will remember all too well the struggle to acquire seeds this past spring. Demand soared to an incredible ten times normal levels in some areas, shops (while they were still open) sold out, and online seed suppliers’ websites crashed under the strain. En masse, millions of people decided to take charge of their food supply and turned to gardening as an at-home source of interest and exercise – and the result was meltdown.
Things have recovered somewhat, but without wanting to get all doom-and-gloomy, if there’s another major spike in COVID-19 cases next year then I expect we’ll see a similar pattern of panic seed-buying. This, in tandem with already-strained seed supplies, means that we may not be able to reliably acquire our favourite seeds again for a while. So it’s only sensible for gardeners to take matters into our own (grubby) hands. There is a way to avoid seed-sourcing calamities, and you can do it even if you’re unable to travel beyond your own back garden.
Plants for Seed Saving
Saving your own seeds means you can be assured of a consistent seed supply, no matter what chaos is raging in the world outside your garden. While planning for seed saving really needs to begin before you plant in spring, there are opportunistic ways to save seeds even at this late stage.
Before you start, first make sure that the plants you want to save seed from are open-pollinated varieties – that is, not hybrids. Hybrids can be identified on the seed packet by the annotation F1 after the variety name.
F1 hybrids are bred from two parent plants to produce a named variety, but seed saved from the hybrid itself will not reproduce the same variety. That’s not to say you can’t save hybrid seeds – just that the results are unpredictable and highly variable, so the next generation is unlikely to closely resemble its parents.
This variability means that every year the same two parent varieties must be crossed again to produce the hybrid variety, which partly explains why hybrids are so much more expensive than open-pollinated (also known as heirloom/heritage) varieties, which breed true every time.
Isolation Distances for Seed Saving
So, now you’ve dismissed any hybrids you might be growing (or not, if you’re feeling adventurous!), the next thing to do is to work out what you can feasibly save seeds from. It’s not just us humans who need to practise social distancing – any plants you want to save seed from do too. If you’re growing more than one variety of the same plant in your garden, chances are your chosen mother plant will cross-pollinate with a sexy stranger from another variety so your baby plants may not resemble their mama as much as you’d like!
Some plants that are largely self-pollinating – for instance tomatoes, green beans (Phaseolus vulgaris), peas and lettuce – are more likely to breed true, even in a smaller garden. In these cases, the mother plant needs to be flowering no closer than 10 feet (3m) from compatible varieties.
Wind-pollinated plants like beetroot and spinach, however, need to be isolated from other plants of the same type because they have extremely light, fine pollen that is easily carried far and wide on air currents – potentially miles! So even if you’re only growing one variety, there’s a good chance they’ll cross-pollinate with plants growing in other gardens, on farms, or with related wild plants.
There are methods you can use to isolate your crops besides physical distancing. Placing barriers such as fences or swathes of flowers between related crops may help to disrupt the path of pollen on the wind and reduce the likelihood of pollen-laden insects travelling between varieties, but this technique can be quite hit-and-miss.
Containment measures – shielding, if you like – are more reliable for crops like alliums and carrots that are typically insect-pollinated. These containment measures can be as simple as tying a net bag over a flower or truss to prevent insects from gaining entry, then taking it off only briefly to hand-pollinate the flowers. Or cover a whole plant with netting, and on alternate days cover any different varieties of compatible plants while leaving the plant you want to save seed from uncovered and able to be freely pollinated.
It’s important to be aware of which crops your plants could potentially cross with, because it’s not always as helpfully straightforward as ‘tomatoes will cross with other tomatoes’. Related species sometimes cross too – for instance, celery and celeriac will cross with each other, as will beetroot with Swiss chard; many brassicas are compatible; squashes may cross within their own genus (Cucurbita pepo, C. maxima, C. mixta or C. moschata); and to make it even more complicated, some cultivated crops will cross with wild plants too, such as carrots with Queen Anne’s Lace.
Seed Storage Life
The great thing about saving seeds is that you often get an awful lot of seeds from very few plants, and in many cases they will keep for yonks, which means you can really slash the cost of your seed bill even if seeds are readily available.
So, using the table below you can see that you’ll need to save seeds of parsnips, leeks, onions and shallots at least every other year, while the chunky seeds of squash only need re-saving every six years (assuming you have gathered enough seed to last you that length of time of course!).
|SEED STORAGE LIFE OF COMMON VEGETABLES |
|Leeks, onions and shallots ||2 years|
|Capsicum and chillies ||3 years |
|Sweet corn ||3 years |
|Broad beans, green beans and runner beans ||4 years |
|Peas ||4 years |
|Tomatoes ||5 years |
|Eggplant ||5 years |
|Beetroot and Swiss chard ||5 years |
|Cucumber ||5 years |
|Lettuce ||6 years |
|Brassicas (eg broccoli, kale, cabbage, cauliflower, kohlrabi, radishes etc) ||6 years |
|Carrot ||6 years |
|Celery and celeriac ||6 years |
|Squash (winter, summer, pumpkin) ||6 years |
Do you have any seed saving tips for your favourite vegetables? Please share them with us and other gardeners below!