Sowing seeds – vegetable and flower seeds

Seeds in Seed Trays

Before sowing any seeds into the trays, give the trays a good wash, if they have been used before. There is no sense in transferring last season’s diseases over to this year’s seedlings.

The type of compost chosen should be dependent on the size of seed being sown. Normally the type of compost the GardenAdvice team recommend for seed sowing the  John Innes seedling or number one compost simply because we have found especially with new gardeners we have a higher success rate. 

When filling a tray, loosely fill to above the rim and then strike off with a flat piece of wood. Firm the corners with fingers ( because it always sinks in the corners) add a little more compost, again to above rim level and then strike off to rim level. With a suitable piece of flat wood (ideally made for the purpose, with a handle on the top and exactly seed tray size) firm the compost evenly so it is depressed by approximately 5 to 10 mm. Do NOT water the compost before sowing. After sowing, give a light sprinkle with a fine rosed can. If recommended cover with a sheet of glass, and also a newspaper or similar if dark is required. 

Whether seeds are covered, and to what depth is dependent on the seed. A covering 4 times the diameter of the seed is a good guide. Some seeds require light to germinate and others require dark. Sowing instructions on the packets or in the catalogue will give the appropriate advice. Placing over some bottom heat will give quicker, and more reliable germination. 20c is enough. i.e over a radiator.

Always sow thinly, even if this means using an extra tray. Thinly means the seed should not be touching. give each seed a bit of space around it. The amount of space will depend on the size of the seed. Use your judgement. Not only does this produce better seedlings, it makes pricking out a far less precise and tedious task. It also allows for some delay, should that happen. Sow thickly and you will not be able to put the pricking out until the following week. 

Seeds in open ground drills 

Sowing into open ground can begin in April. It isn’t often the case that the soil will be suitable for outdoor sowing in March, even though advice in Gardening books etc often recommends outdoor sowing then. It may be possible in very mild areas, but in most areas of the UK, April is more realistic.

The soil preferably will have been dug well in advance of sowing and left to settle. At sowing time apply whatever fertilizer is appropriate and work it well into the top 5 to 10cm with a 3 or 5 pronged cultivator. At the same time this cultivating will break the lumps down.

To firm the soil and break down lumps still further, the ground should be trod. Work either up and down the plot, or go round and round, ending up in the middle. Keep feet together and shuffle along rather than stamp the feet. 

The next task is to rake the soil to a fine tilth. Use a wide wooden rake. the type which has a line of pegs about 4cm apart. These rakes are light and easy to use. Move over the soil in a back and forth motion to separate the stones from the soil. The only heaps being borrowed away from the plot should be stones and any debris that was left. Anyone ending up with heaps of good soil and heaps of soil lumps, is doing it wrong. Narrow metal rakes are heavy and difficult to use precisely. They are best used just for very firm seedbeds needing a very fine tilth. They tend to go too far in, and rake off the good soil as well, unless the user is highly skilled at taking the wooden type.

The best conditions for treading and raking is on the day after some light rain. Just enough to leave the soil slightly moist. It is almost impossible to tread and rake a bed to a fine tilth if the soil has been baked hard by hot dry weather. Neither is it possible on soil which is like a bog. The timing really is important. 

When sowing in drills a garden line which can be pulled is taught as the best guide to drawing out a straight drill. Short drills of less than about 2 mtrs can be drawn against a straight plank of wood or a cane. Another good way is to lay a broom handle (without its brush attached) down and tread along it, to make a neat depression. The plants will not mind if the drills are perfectly straight or not, but it certainly does look better if they are. It also makes managing the rows easier. Messy untidy gardening reflects badly on the Gardener, even if the Gardener is an expert in all other respects. 

Broadcast sowing which is occasionally recommended by Garden Writers is best avoided. It is seen as a way of making the most use of available space, but can be a nightmare to manage. Anyone who has tried this method will know that it is impossible to separate the weeds from the plants (assuming the gardener can tell which is which) Hoeing is not possible either, and also if a large area is broadcast sown, then there will not be anywhere to walk. In drills you know what is what and where it is. walking between rows is easy and hoeing can be carried out with no difficulty. 

To backfill the drills the best way is to use the feet, heals together and toes at 11.05 on the clock face. Carefully going left forward, then right forward along the row will fill the drills and leave a slight ridge. This ridge can then be tamped down with the back of a metal rake to firm the seeds in and mark where they are. It’s quite skilled, and beginners and the less confident can always fill in drills with a mix of sieved soil and multi purpose compost. Adding perlite to this mix is a good idea, as it serves as a marker for the rows. After filling and  tamp down with the back of a rake in just the same way.

If required give the newly sown rows a watering with a fine rosed can. Protect from Birds or Cats or any other seedbed nuisance, if they are known to be a problem.