When you save your own seeds, the difference is striking. They are much fresher and just want to grow, as long as you observe the basic tenets, such as plant numbers for cross-pollination. First off, however, I want to explain hybrid breeding.

F1 hybrids

Vegetable breeding in the last three or four decades has concentrated on hybrid varieties, many of which grow excellent vegetables, with high yields and good flavour. Unfortunately, from a seed saver’s perspective, they don’t breed true. For example, do not save seed of hybrid tomato varieties such as Sungold and Rosada F1. Plants I grew from ten seeds of Sungold grew tomatoes of varied shape and colour, and none were sweet or especially flavoursome.

• F1 seeds are the result of firstly inbreeding two generations of plants to achieve desirable traits, then cross-pollinating the two lines, sometimes in a forced way.
• The result is only one generation of a desired outcome and, if you sow seeds from those plants, your new plants have a random mix of less desirable traits.

Seed packets state ‘F1’ if they are hybrids. The process does not involve genetic modification, nor is it a natural method. The results are predictable, consistent and profitable, the reason for seed producers favouring work on F1 hybrids, rather than on open-pollinated strains (see Lesson 5 for a negative consequence of this).

New plants from sideshoots

For certain vegetables, another option for raising plants is vegetative reproduction, as with slips of sweet potato, the stem plus root of perennial onions, and sideshoots of tomato plants. The latter involves a fair amount of time, to keep them alive and healthy all winter. I do this with Rosada tomatoes because they are an F1 variety, so the seeds you save won’t grow true, and Rosada seeds are no longer available to buy.

Here I explain the different methods you need for a range of vegetables. Some are easy to save seed from, while some need more time and space, and careful selection of the seed-saving stock. If you have not saved seed before, I advise starting with any of French bean, lettuce, pea or tomato. These four vegetables neither need nor are altered by cross-pollination.

Onions

The best results happen in a dry summer.

• First, grow your onions, in the preceding year.
• Select the largest and best, and replant them in early spring, say, 5 cm / 2 in below surface level. The stems may need support because they grow tall, and the seedheads are quite heavy when wet.
• Check for ripeness by rubbing a floret or two, in search of the hard black seeds.
• Cut off the heads and put them somewhere very dry, until almost crisp, then rub out the seeds by hand, wood or foot.

Peas and beans

These are easy to save because seed is mature just one month or so after the normal period of eating them.

PEAS AND FRENCH BEANS

From mature peas at their normal picking stage, it takes two to four weeks of summer weather to have dry peas for a seed harvest, and for French beans a little longer.

Peas and French beans do not cross-pollinate, therefore:

• Just one plant of any one variety will give viable seed, true to type.
• Different varieties in close proximity stay true to their variety when you save the seed.

BROAD BEANS

These grow in the same way as peas, except that the pods turn black when dry and with ripe seeds.

The main difference from peas is that cross-pollination happens, so if you save seed from, say, two varieties in the same garden, or on an allotment site where many are growing, the new seed will not grow true. The same applies to runner (pole) beans.

One reliable variety to start with is Aquadulce Claudia.

CLIMBING BEANS

These are easy to save but later to mature than peas and broad beans. In regions with cool, damp summers and autumns, they may not be viable. Even at Homeacres, I lose a small amount of potential seed harvest in some Octobers. They do cross-pollinate.

We shell out the Czar seeds pod by pod, but Borlotti pods are smaller and also hard when dry. This makes it more effective to walk on them, in order to crack open a lot of pods very quickly.

Potatoes and garlic

I have saved garlic seed for two decades, and no problems yet! The only limiting factor would be if you suffered white rot, which can even be on some bought garlic seed, though this is fortunately rare.

Garlic ‘seeds’, by the way, are actually cloves of garlic which you separate from preferably large bulbs.

The constraint in saving potato seed is whether there may be either blackleg or virus. The former shows as plants prematurely dying with black, rotting stems (see ‘Disease’ section in Lesson 4 for more information), and the latter as leaves turning bright yellow. If free of those easily recognised problems, save seed of medium-sized potatoes, including any that are too green to eat.

Leaves

These are fiddly and often take longer. The positive aspect is that you may harvest a large number of seeds from one plant: over 2,000, say, for lettuce.

LETTUCE

In dry climates these are easy, but if there is too much damp weather as flowers turn to seeds in late summer, the seedheads risk rotting just before harvest. The timing goes like this:

• Sow in either early autumn or late winter – lettuce plants survive frost, so autumn sowing works well where winters are not too cold, say above –10°C / 14°F. Plants have more time to produce seed in the following summer when they are sown in early autumn.
• Leave unpicked in spring, so that their heart or head opens into an uprising flower stem by early summer.
• Small yellow flowers develop in summer, into tight clusters of ten to fifteen seeds.
• Once you can separate seeds from the clusters, twist out the whole plant and hang it somewhere dry to finish the seed-drying process.
• Rub out the seeds and winnow in any gentle breeze, usually in early autumn.

SPINACH (AND BEETROOT)

These seeds are more difficult to save than those of lettuce, because you need at least six to eight plants for cross-pollination and the seeds are clustered in florets, which are slow to mature and difficult to separate from plant stems.

Wait until the stems and seeds are reasonably dry, before the end of summer, then twist out he plants and rub off their seeds.

It’s the same method for growing beetroot seed. Plant a minimum of six beetroot in early spring; the seeds dry by late summer and you can then cut the umbels before the seeds fall out, allow them to dry, and then rub out the seeds.

• Subsequent growth from the spinach in the photos, below, was variable to the point that it behaved like a different variety: the leaves were darker green, rounder and more prone to slug damage. Perhaps there were too few plants to ensure cross-pollination.
• Medania is called a ‘type’ of spinach as opposed to a ‘variety’ or ‘cultivar’, so perhaps this variation is normal when saving its seed; we did not select it for any desired traits.
• Subsequent seed saving in summer 2020, from these ‘new’ Medania, has resulted in stronger plants, all dark green and less troubled by slugs than normal.
• My new strain starts more slowly, and then grows for three weeks longer before going to seed, compared to its ‘parent’ Medania.

MUSTARD

Again, you need cross-pollination and preferably an overwintered plant, since mustards are biennial, like spinach.

Sow in September, then by April you will have yellow flowers and many insects, with seed pods developing in May and ripening in June to July. We then twist out plants and walk on them to break open the small pods.

This is best done outside in a slight breeze. The idea is for the breeze to blow away fragments of pea or bean pods, lettuce fluff, bits of dry spinach leaf or small pieces of coriander pods.

• Using two buckets, let seed drop from one bucket to the other in a steady flow, and always watch the seed going in rather than fluff flying out, to be sure that the seed itself is not blowing away. Repeat two to four times, and beware of wind gusts.

Often there are a few unwanted bits after winnowing, and you can pick out the larger ones. Most of the non-seed residue is dry and does not affect keeping quality or germination percentages. Clean the seed as much as you can, without worrying that it looks imperfect.

Tomatoes

Be sure to only save seed from open-pollinated varieties, not hybrids (see below).

• Tomatoes do not cross-pollinate. This allows us to save seeds from tomatoes of two different varieties, grown right next to each other.

If growing more than one plant of a variety, save seed from a fruit growing on the plant that has the nicest growth habit and harvest:

1. Cut your tomato, as if preparing it to eat, and scoop out any seeds using a spoon.
2. Place the seeds, and any tomato fruit sticking to them, in a cup with some water, and leave in the kitchen to ferment. This breaks down germination inhibitors on the seed, through fungal action.
3. After five to seven days, you will probably notice a black mould of decaying fruit pulp on top of the water, which you can scoop off; the seeds will be at the bottom, now much cleaner.
4. Give seeds a rinse and then place, say, on cardboard, in a dry place for a few days. Then pop into an envelope or an old seed packet, clearly labelled.
5. Tomato seeds store for up to ten years, in any dry environment. A dry and ambient temperature is better than a cold and damp one.

Other vegetables

For all other vegetables not mentioned so far, I recommend that you are careful before setting out to save seed, especially in a small garden. Cabbage, carrots, kale, leeks or sweetcorn, plus many others, all need several plants growing together to ensure that there is a sufficient gene pool for healthy cross-pollination and maintenance of the varietal traits. This means that you need a lot of space to grow them. Also, root vegetables take a second year because the flower stems don’t develop until year two, after you have grown the harvest in year one.

A drive for profitability has resulted in less work to maintain ‘trueness to type’ of older varieties, because revenue is higher from the exciting results of new work on hybrids.

• Maintenance of an open-pollinated (OP) variety / cultivar involves selecting the plants whose traits are most true to the characteristics desired. This is the basis of seed production for older and open-pollinated vegetable varieties such as Boltardy beetroot, Greyhound cabbage and White Lisbon spring onions.

A sad example of cost-cutting is with the Gardener’s Delight tomato. The fruits are now considerably larger, thicker-skinned, of paler colour and less sweet than they were in the 1980s, when it was the standard and best cherry tomato. This loss of quality makes F1 seed more desirable.

I have grown Greyhound cabbage for 40 years and it has always hearted early, starting in late May. However, in 2019, the plants didn’t make firm hearts at all. I had feedback of similar results from other gardeners. We waited and waited, for a disappointing and late harvest.

Often, if you grow enough plants of non-hybrids, you get an idea of any variety’s growth characteristics and uniformity, or lack of it. Usually there are a few, but not too many, genetic throwbacks (also called ‘sports’) to a wider gene pool, such as white beetroot and yellow carrots, which may also be tough and fibrous.

With chicories, there has been insufficient breeding in general, except by a few sellers, notably Sativa in Switzerland and Bingenheim in Germany. Until I discovered the latter two suppliers, all Palla Rossa chicories I grew, except for hybrids, were 30–40% useless for hearts, and often rotted once there was any firmness.

I reckon the three example in the photos below are simply a result of poor maintenance. The radish Poloneza was brilliantly uniform in 2016, with a nice root-leaf balance.

Just two years later, the Poloneza I bought from the same company (Kings) had a higher proportion of leaf and less plumpness of root.

The St Valery carrots were my worst experience to date (2019) of bad seed maintenance. When I sent the photo to Mr Fothergills, they said how much they agreed with my concerns, and were themselves appalled!