Germinating seed in media.`

From King Henry’s Walk Garden:

Sowing indoors

  • Use sterilized compost and clean pots.
  • Water the compost well before sowing.
  • Sow thinly and not too deeply – this is the commonest cause of failure.
  • Follow the directions on the packet. If there are no directions, a rough guide is two-and-a-half-times the depth of the seed. Fine seed, like carrot, is easier to sow evenly if you mix it with silver sand. Scatter the seed as thinly as you can on the surface and sieve some fine compost on top. Cover the seeds with clingfilm, glass or a black plastic sack. They will be kept moist by condensation and shouldn’t need to be watered again until the seeds have germinated. Keep them in the dark in the airing cupboard or in another warm place. Check every day. As soon as you see signs of life, take off the covers and get them into the light, but out of direct sunlight. Keep some water at room temperature for them, but avoid overwatering them as they could ‘dampen off’. Though generally rain water is recommended for plants, for seedlings tap water is safer. If they are on a window sill, turn them every day or put them in a box lined with kitchen foil to reflect light around the young plants.

    Pricking out

    Don’t hurry this! Aim to be efficient to minimize the time they are out of the soil. Water them well ahead of time. Have ready some containers filled with compost with holes made with a dibber (pencil, plant label, lollipop stick or chopstick) ready to receive them. Ease out the seedlings with a dibber taking as much compost with them as possible to avoid damaging the roots and to prevent them drying out. If you need to handle the seedlings or support them, don’t touch the stems as they are easily broken, just the leaves. Plant them so that the first set of leaves is just above the surface of the compost. Firm them down carefully and water.

    Hardening off

    Prepare the young plants for the outside world in stages. Be patient and wait until the weather is really set fair. Put them out under cloches, fleece or in the cold frame. If you keep them in their pots for the first few weeks they are easy to move indoors if there is an unexpected cold snap. Alternatively cover them with thick newspaper if you expect a frosty night – removing it in the morning. On fine days take off the crop covers and put them back on at night, until you are sure that the young plants have acclimatized.

    Planting out

    When they are ready to go out into the ground, water them well before moving them from their pots. Plant them to the same level as before. An exception to this rule is leeks which are planted more deeply to keep them blanched. Water again carefully to get rid of any air pockets.

    Sowing outdoors

    Prepare the beds carefully. Clear away all weeds and stones. Work the soil to a fine tilth by moving the rake across and then lengthways over and over again until the soil is flat and smooth and has the texture of fine breadcrumbs. The finer the seed that you plan to sow, the finer the tilth should be. When you are satisfied, firm the soil with the back of the rake.


    Drills are trenches that are used for sowing most vegetable seed. They can be a narrow ‘V’ shape for fine seed made by the corner of a hoe, or wide enough for two lines of seeds made with the full width of the hoe. Some gardeners tread on a stick instead to make a low indentation. The seed is sown in straight lines or geometric patterns so that the gardener can discern what is weed and what is seed. Use pegs or skewers and string to give you a guideline, then make a drill with a corner of the hoe or a stick. Be careful not to make it too deep. Water the trench before sowing the seed. One way is to sprinkle the seed into the palm of one hand and take pinches with the other to sow as thinly as you can. Another is to tip it slowly out of a folded piece of paper. If the seed is very fine, mix it with silver sand or a little compost. Cover the trench, taking care not to bury the seed too deeply. Mark the spot and label it (golden rule).

    Station sowing

    Station sowing is for larger seeds like broad beans and peas. Prepare the ground in the same way but instead of making a drill, make holes at the appropriate distances along the line. Often peas and beans are sown in a staggered double row. Drop the seeds into the holes one by one. It is customary to sow three seeds per station – one for you, one for the birds, and one for luck.


    This is used for a carpet covering, a lawn, a wildflower meadow or green manure. Once the beds are prepared, the seed is sown by scattering it. Usually the best method is to walk up the bed and then across it using a wide sweep of the arm.

    Pre-germinating seed*

    This is a useful technique for getting tricky seeds like parsnip to germinate quickly and also to test whether old seed is still ‘viable’ or alive. Scatter a few seeds on a sopping wet kitchen towel, cover them with a plastic bag and put them in a dark warm place like the airing cupboard. Watch them carefully over the next few days as you want to catch them when they are embryonic, just putting out almost invisible roots and shoots. If you leave them too long they are very vulnerable to damage. Fluid sowing This is a commercial technique useful for ‘difficult’ seeds but it can easily be adapted to home use.

    Pre-germinate as above.*

    Rinse the seeds off carefully in a sieve. Mix up a carrier gel of water-retaining granules (available at garden centres). Drop a few seeds into the mixture with the tip of a plant label or tweezers. If they sink, the gel needs to be thicker. When you have the right viscosity and there are plenty of seeds in the mix, put it in a heavy weight plastic bag. Cut off the corner and squeeze out the mixture into a prepared trench – rather like icing a cake for giants. Thinning

    Thinning seeds is essential to give your plants the best chance of developing well. Check on

    your planting distances and be ruthless. If you are careful, sometimes the thinnings can be transplanted or (like carrots) be eaten. Types of seed

    Treated seeds

    Pelleted seed. This is a helpful treatment for tiny seeds – some come as fine as dust. Each seed

    comes as a small ball coated with an inert protective material, so that it is easy to handle and sow. It is important to keep the soil comfortably moist so that the pellet can gradually dissolve.

    Seed tapes. The fool proof way to sow. Seeds are embedded in soluble tape, perfectly spaced.

    So they just need to be laid on the soil and covered in the usual way. Chitted and pre-germinated seed. The seeds are despatched when they are just germinated with microscopic roots and shoots. This can be a useful shortcut. However, it is easy to pregerminate your own seeds.*

    Primed seed. The seed is brought almost (but not quite) to the point of germination to give it a

    head start. This is helpful with ‘difficult’ seeds – ones that germinate slowly or erratically – e.g. carrot, parsnip, onion and parsley. Dressed and treated seed is to be avoided by organic gardeners as the seeds are treated with chemicals. F1 hybrids F1 hybrids (the first filial generation, or ‘Filial 1’) are made by crossing two distinct parent lines. The aim is to achieve the virtues of both. Most new vegetable varieties are F1 hybrids. The advantages are exceptional quality, uniformity, reliability, vigour, and often inbuilt disease resistance. They are to be highly recommended. The only drawbacks are that they don’t come true from seed and they are more expensive. Award of Garden Merit Seeds that have the AGM have been vigorously tested by the Royal Horticultural Society for excellence for ordinary garden use, are readily available, have a good constitution, do not need specialist care and are not susceptible to disease. It is always worth looking out for the AGM sign (a little trophy cup). The full list can be downloaded from