Sowing seeds in the ground

When sowing outside at the start of the season you need to keep in mind the type of soil you have. Clay soil will take longer to warm up in the spring than sandy soil, so you should delay sowing for a few weeks until the soil is warmer. Alternatively, cover the soil with horticultural fleece, a cloche or straw a few weeks before sowing to warm the soil up and keep the covers on until the plants are established (but don’t let the coverings touch the plants). Covering the soil can also enable you to plant even earlier on sandy soil.

When sowing seeds outside it is vital that you prepare the site before sowing. The site should be sheltered, weed free and cultivated to a spade’s depth (a ’spit’) with organic matter, such as well rotted leaves, incorporated. Creating a raised bed can help to achieve an even and well drained surface. For vegetables this initial preparation can be done in the autumn, before spring sowing, as freshly manured land can result in forked roots (eg of carrots).

Just before sowing, the soil should be raked over to remove any stones and break down clumps of soil so the surface becomes friable. Shuffle over the soil (or pad it down with the back of a rake) to firm the surface.

Seeds can be sown in drills or, for larger seeds, in individual holes created with a dibber. To form a drill, use a taut line to measure out where the drill will go and, using a cane or the corner of a rake or hoe, create a shallow drill in the soil along the line (the line should also help you keep it straight). If you are making individual holes, set the taut line and then make the holes using a dibber or cane along the line. If you have very heavy or wet soil add some silver sand or fine grit into the base of the drill/hole and cover the seeds with a layer of it. The depth of the drill/holes, the spacing between seeds, how many seeds to put at each point (or ’station’) and the spacing between rows of seeds will vary from plant to plant. Sow the seeds in the drill or hole and gently cover with soil using the rake. Firm down over the line with the back of the rake.

For some vegetables time can be saved by creating wide drills with the flat of a hoe or the back of a narrow rake. The seeds can then be sown broadcast or spaced evenly along and across the wide drill. This is useful for vegetables such as carrots and radishes.

As with sowing seeds in pots and trays, very fine seeds can be mixed with silver sand and sown off a sheet of folded card to ensure an even distribution.

Some vegetables (including beetroots and carrots) need a higher temperature to germinate than to grow on. These can be ‘pre-germinated’ at 21°C on damp paper towels for 24-48 hours, until the seeds are swollen and starting to germinate. The seeds are then mixed with a clear gel (such as wallpaper paste, making sure it doesn’t contain a fungicide), placed in a plastic bag and the corner cut off the plastic bag to allow the gel to trickle out when the bag is squeezed. This allows an even distribution of the seeds without damaging them. Pre-germination will also help the seedlings grow more quickly.

If you are sowing tree seeds, apply a 2cm deep layer of 3-8mm grit over the entire seed bed. If you are sowing shrubs, then cover with 2-3cm of pea shingle. Slow growing perennials should be covered with fine gravel.

For bedding displays you may wish to sow the seeds over a particular area where they are to remain. This can be done by sowing in drills, as described above, which may seem very formal at first (once the plants are larger it won’t be obvious they are in rows), but has the advantage that the seedlings are easily identifiable as separate from any weeds growing.

Alternatively you can sow them broadcast over the area (this is also a useful technique for some vegetables, such as radishes). To do this, rake the area to a fine tilthe and scatter the seeds thinly over the area. Then lightly rake over the area, doing this twice and moving your position to the side of the bed for the second raking so you are raking at right angles and water the soil with a fine rose.

The seedlings will be vulnerable to birds when they initially appear, so you may wish to add some protection. This can be twiggy sticks laid over the bed, chicken wire bent over to cover the bed or netting suspended above the bed and extending down to ground level.