Choosing Seeds
The majority of vegetables grown in home gardens are raised from seed planted directly in the soil, rather than from transplants. Seeds for vegetables are now available in a variety of ways, many of which are designed to make sowing and germination easier.
It is always advisable to buy fresh, disease-free seed each season from a reputable company; old or 'bargain' seeds often turn out to be non-viable and not such a bargain after all.
Seeds may be bought at a garden centre or from a seed catalogue. Catalogues are often available in winter and have the benefit of offering you the opportunity to browse through the varieties at you leisure, giving you plenty of time to decide upon what to grow and how much seed you will need to order. By ordering early, you will receive the seed in plenty of time for planting, and you will avoid the chance that a choice variety may be sold out. You also have the advantage of selecting new or superior varieties that may not be available on seed racks at a garden centre, nursery or supermarket.
Always check out the descriptions on seed packets; they are full of useful information about potential difficulties, sowing times, spacings, temperatures, the number of seeds in the packet and the likely number of plants that will be raised from them.
Seed Types
F1 (first generation) and F2 (second generation) hybrid seeds are available for many plants; these seeds are much more expensive than open-pollinated versions, but produce plants that are vigorous and true to type with even growth and flower characteristics.
F1 hybrids come from two pure-breeding parents that produce offspring which have particular positive characteristics, such as uniform size and shape and vigour. F2 hybrids result from self- or cross-fertilization of F1 hybrids: they are less uniform than their parents.
Whilst some F1 seeds, such as pelargoniums and Brussels sprouts are worth investing in, open-pollinated seeds are quite acceptable for the majority of species grown by most gardeners and will provide some interesting variation in the plants. If you do buy F1 seeds, do bear in mind that you will not be able collect and grow seeds produced by F1 hybrid flowers or vegetables as their offspring will not come true to type.
Always buy fresh seeds that have been stored in cool conditions. Although seeds in sealed foil packets may last for several years, the seed will start to deteriorate as soon as the packet is opened.
Seed Format
Seeds are often supplied in various different formats to make it easier for the gardener to sow them accurately and easily.
1. Pelleted Seeds
Some F1 and F2 hybrid seeds may be coated with a clay-based paste so that they form a round pellet. This means that they can be handled more easily, so that they can be planted individually in containers or the open ground. As the seeds can be sown at the correct planting distances, the need for thinning is reduced, which means that more viable plants are produced per packet.
Pelleted seeds are usually primed (see below), and so should not normally be stored for more than a year.
2. Primed Seeds
Primed seeds have been pre-treated so that they are ready to germinate as soon as they are sown. This is carried out by exposing the seeds to water so that they swell, and then drying them just as they are about to break out of their coat (i.e. germinate). This has the advantage of improving the germination vigour of the seeds. However, although this is useful for species and cultivars that do not germinate easily, it also shortens the lifespan of these seeds. Any primed seeds should be planted as soon as possible; do not store them for more than a year.
3. Seed Gels
One way to sow seeds evenly is by using a gel kit. Seeds are added to a paste which may be squeezed along a pre-prepared drill. This distributes the seeds evenly so that less thinning is required.
4. Seed Tapes
Seed tapes are tissue paper strips filled with evenly-spaced seeds. The tapes are laid in a shallow drill (6-13mm or 1/4-1/2 in deep), covered with soil and then watered. As the tissue paper becomes moist, it germinates the seeds, then dissolves into the soil. This should result in a line of perfectly spaced seedlings, with no need to thin. They are available in tapes and circles, which may be cut to fit the size of your container.
5. Chitted Seed
Chitted (or pre-germinated) seed may be supplied just as the seed coat has burst open and roots and seed leaves are starting to emerge. They are usually supplied on agar jelly, which provides them with enough food and moisture for a few days; they should be transferred to the right growing conditions as soon as they are purchased so that they can continue to develop.
Seeds may also be pre-germinated at home. This involves placing them on moist kitchen paper and leaving in a warm place, then planting them individually in small pots or in open ground as soon as the first signs of germination are seen. Chitting seeds before planting ensures a high success rate, as any that do not germinate can be discarded, guaranteeing an evenly-spaced row of beautifully grown vegetables at each planting. It can also be a good way to test a sample of old seed for viability before sowing.
Chitted seeds are full of water, and as long as they are planted in damp soil and the bed is watered again immediately after planting, their moisture needs thereafter are relatively modest, especially if the soil around them is heavily mulched.