This weekend I had the pleasure of test driving some seed tapes. I’d never heard of them before, but when they arrived, I could instantly see how they could be the perfect introduction to vegetable growing for first time growers…
Saving pumpkin seeds is easy peasy. If you have had a good healthy plant, or an heirloom variety and you want to save some seeds for next year, there’s nothing to it. Of course you will have many more seeds than you need in every pumpkin and you can use the rest in your recipes or as wholesome snacks. Learn more
All varieties of melon will cross. Ideally, you need around a quarter of a mile between different varieties. If your melons are in a greenhouse or tunnel, you can probably get away with a somewhat smaller distance, particularly if there are hedges, houses or other tall barriers in between your melons and the neighbouring crop. Cucumbers won’t cross with melons, but will cross with any other cucumbers or gherkins nearby. Again, you need around a quarter mile isolation to make sure that your plants won’t cross.
Beware that pumpkins, squashes, marrows & courgettes will all cross readily with each other. The best (usually only) way to save pure seed on a home scale is to hand pollinate one or more fruits. This is very easy & will avoid disappointments with lumpen squash/courgette crosses. The explanation given here is for pumpkins, but applies equally to squashes, courgettes & marrows.
Sprouting broccoli, cabbages, cauliflowers, calabrese, kales and brussels sprouts are all members of the same family (Brassica oleraceae), and will all cross with each other. They won’t cross with turnips, swedes, oriental brassicas or mustard greens. In addition, they are mainly self-incompatible – which means that in order to get seed, insects have to carry pollen from one plant to another to pollinate the flowers. Because of this, you can’t simply grow your broccoli or cabbages for seed in an insect proof cage to avoid crossing.
So long as you only seedsave from one member of the family in any given year, you can grow as many other brassicas as you like without problems so long as you don’t let them flower.
Basil, coriander and dill are annuals, parsley is a biennial, flowering in its second year of growth.
Basil flowers are insect pollinated, and different varieties flowering within around 150’ of one another may cross. On a garden scale, if you want to grow several types of basil, just keep picking the flower stalks off of all the varieties apart from the one that you want to grow for seed. Once several flower spikes have set and the flowers have started to wither, mark those spikes for saving seed from, and you can then allow the other varieties to flower. The seeds are ready to collect when the spikes turn brown and dry out. Don’t worry about the seeds dropping out – they are well attached, and actually need quite a lot of rubbing to free from the dead flower heads.
Carrots are biennial, flowering in their second year of growth. In areas with mild winters, leave your carrots in the ground, mulching them heavily. The foliage will die back in autumn, but will then resprout and start to flower in the spring. In colder areas, dig up your carrots in the autumn, and select the best coloured and shaped roots. Twist off the foliage, and store the roots in a box of dry sand in a frost free place, making sure that they don’t touch. In spring, replant the roots, and they will resprout and flower.
If you want to maintain a carrot variety effectively, you really need to save seed from at least 40 good roots to maintain good genetic diversity. If you have too small a genetic pool, you will end up with small, poor quality roots in a very few generations.
Beetroot, leaf beet/perpetual spinach, swiss chard & sugar beet are all members of the same family & will cross readily. They are biennial, and flower in their second year. Chard/leaf beet for seed are overwintered in situ, and will be fine in most of the UK. Select a minimum of six to eight plants to leave for seed which best fit your needs (depending on your preference for stem versus leaf, smooth or wrinkled leaves etc). Beetroot can also be overwintered in situ, or can be harvested in autumn, the best plants selected & stored then replanted in spring.
Most modern varieties of tomato are self pollinating, and will not cross. The anthers on tomato flowers (which make the pollen) are fused together to make a tight cone that insects cannot enter. Usually the stigma (the receptive surface for receiving pollen) is very short, and so is located deep inside this cone of anthers. No insects can get to it and the only pollen that can fertilise it comes from the surrounding cone of anthers.
Making an isolation cage
To make a simple isolation cage ideal for peppers or aubergines, you need some cheap nylon flyscreen 5 times as long as it is wide, four canes or thin stakes, and some string and garden wire. Alternatively, you can use old net curtains, or other netting small enough to exclude insects. A piece of screen 1m by 5m will give a cage large enough to cover 3 or 4 plants. Learn more