No. 16
BEETROOT & CHARD
Beta vulgaris
Family: Chenopodiacecae
Beetroot seed saving guide also available here as a PDF document (181Kb)
Beetroot and chard are the same species selected for different purposes, either the size of the root or the production of the leaves (often for their startling colour and wide midrib). They will cross-pollinate with each other, but not with true spinach which is a different genus.
The 'seeds' of beetroot are actually corky fruits or seed clusters, which normally contain anything between two and four seeds.
Flowers are mainly wind-pollinated.
Growing and Roguing
Beetroot and chard are biennial, grown one year to produce seed the next.
Producing seed from overwintered roots
- Grow the roots as normal for the first year, sowing in spring and storing the best roots in autumn for replanting the following year. Lifting and storing them allows you to select those with the shape, colour and size most typical of the variety. Store roots in damp sand, or black plastic bags with holes cut in them, in a cool, frost-free place. Any roots that are not storing well or are misshapen can be eaten. Do not save seed from plants that flower the first year.
- Beetroot are 'outbreeders'; you should select and keep as many as you can in order to preserve the health and genetic diversity of the variety — ideally at least 16.
- Plant out the best beetroot roots in spring as soon as danger of severe frost has passed. Plant them firmly in blocks or rows at least 30cm apart and with their crown at soil level. Water well to encourage re-rooting. Chard should have similar spacing.
Producing seed from overwintered plants
Chard
- Another method is to overwinter plants rather than mature roots. Sow the seed in August and overwinter them with protection either in a glasshouse or tunnel, under cloches, or in pots (three to a 20cm pot) to be planted out in the spring. Beetroot and chard need cold treatment (vernalisation) to induce flowering.
- Sown in this way, the plants should flower in June (requiring isolation), with seed ready to harvest from September. This method gets round the problem of storing roots and occupies the ground for less time. Chard is hardy enough to be left in the ground and the best plants allowed to seed in-situ the next spring.
- The tall twisting flower spikes of beetroot are surprisingly attractive and smell delightfully like honey. The spikes are branched and can grow to 1m or more, needing good staking.
Pollination and Isolation
All beets cross-pollinate with each other. Spinach beet, being a different type of chard, will also cross-pollinate with beetroot and chard, as will sugar beet (watch out for a field of sugar beet nearby where there may be plants in flower).
The pollen can be wind-borne over long distances so isolation is important. Commercial seed growers recommend an isolation distance of 500m minimum for similar varieties (e.g. between two globe-shaped beetroots) and 1-3km for different types of crops (e.g. between beetroot and sugar beet). If you are confident that no other beet, chard or sugar beet is flowering around you, and you save only one variety each year, you may not need to worry about cross-pollination. Crops grown for eating are not a threat, provided any 'bolters' are removed before flowering.
Isolation can also be achieved by 'bagging' or using horticultural fleece. Isolate as soon as the first flowers start to form. Insect proof mesh is not suitable as the pollen is fine enough to pass through even a very fine mesh. Horticultural fleece is a better barrier, but can cause problems with humidity.
Push a stake into the middle of each circle of plants and gently bend all the flower stalks towards it. Cover the flowers with a large potato sack and tie round the base. Some sort of cushioning (cotton wool or soft paper towel), will be needed to reduce abrasion round the stems and to prevent stray insects and pollen getting in. On still days shake the bag to keep the pollen moving and ensure seed set.
It is possible to bag using a potato sack over six or seven plants at a time. This should not be used every year as it is necessary to use a minimum of 16 plants, covered together to allow cross-pollination, to maintain the health and diversity of the variety.
Harvesting
The seeds are mature when they start to turn brown, which they do successively from the base of the flower spike upwards, and when the stems are brown and crispy. They do not fall off readily so can be left on the plant until all are ripe, then harvest the whole stem. Remove covers when flowering has finished to let in light and air. Inspect regularly to see when the seed clusters start to form.
Cleaning
Beetroot gone to seed
Cleaning refers to the removal of chaff and debris, leaving only seed. Cleaned seed keeps better.
The mature seed clusters can easily be stripped from the stalks by hand. Pinch off the tips of the stalks where the seed clusters are small and immature, and sieve to remove any debris or dust. There is no need to separate the seed clusters, they are normally supplied this way and separation can injure the seeds.
Storage
Beet seed will store for up to six years. Expect 50% germination.
Returning Seed to HSL
It is important that seed returned to HSL is not cross-pollinated. Do not send us seed that you suspect might have crossed.
Seed must be completely dry and fully cleaned. Seed that retains moisture can go mouldy in transit and will have to be discarded. It can take a few days to get to us in the post. Pack it in breathable material (e.g. a paper envelope or cotton bag) and place it in a padded envelope or stout box to protect the delicate seed from impact damage, before sending it in the post.
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