Sowing in Open Ground

Richard Bird considers an alternative way of growing seed that is often overshadowed by pot culture.

Many authors often refer (which they frequently do!) to growing from seed, and it is always assumed that the seed will be sown in pans, pots or trays. There are obviously many advantages to this. In particular one has much greater control over the growing medium with regard to its composition, water retentiveness and the amount of heat, water, fertiliser and light that it receives. Growing seed outside in the open ground is more hazardous as it is not so easy to control these factors. Yet gardeners, and more obviously farmers, have for generations used this method. It seems safe to assume that this would have been the earliest method of sowing seed.

There are many plants that produce seed that germinates very readily and does not need the cossetted conditions of the pan. This saves the grower a lot of time and energy as well as releasing hard-pressed space in propagators and frames. Admittedly an eye must be kept on the weather conditions and water must be provided if necessary, but the vast volume of soil does not dry out as readily as a pot and generally the seed can be left to germinate without any attention at all. Many plants are sown in situ so that there is no pricking out or potting on to do which always causes a check in the plant's growth. Another advantage is that there is no hardening off (a very necessary process that I hate) to bother with, which again can cause a check.

The most obvious choice of candidates for this kind of sowing is, of course, vegetables. Most of these will germinate happily outside in the open soil. The only time when it is worth sowing them in pots is early in the year so that the growing plants can be planted outside immediately after the last frosts (or earlier if they are kept under cloches). This will inevitably lead to an earlier cropping. Another reason for growing in pots may be to produce mature plants that can be used immediately as replacement crops when a piece of ground is cleared of one that is finished. These reasons aside, the majority of vegetables are sown direct.

In the flower garden a lot of annuals can be sown direct in the soil, particularly the hardy annuals some of which, such as the cornflowers, can be sown in the autumn. This has the advantage that the resulting plants flower much earlier in the year, giving them potentially a longer flowering season. The tender annuals must, of course, be sown in late spring so that they do not appear before the frosts have passed. Here it can be advantageous to sow in pots as mature plants can be produced ready for planting out by about the same time as one would sow outside.

As well as annuals a lot of perennials (particularly the larger stronger growing ones) can be grown outside including herbaceous plants such as delphiniums, lupins, hollyhocks and so on. These would be sown in a reserve bed or vegetable garden and grown there until they were big enough to plant in their permanent positions. The main advantage of this is that a lot of plants can be grown with the minimum of trouble; to prick out and pot on, say, a couple of hundred of one species just to find out if there are any good coloured forms that are worth growing on takes up a lot of effort, not to say space and compost; and can be more easily achieved in the open ground.

Trees and shrubs which are needed in quantity particularly for hedging can be sown outside, which has the advantage of allowing them a natural stratification as they are open to the elements.

Ground preparation

One of the first requirements for sowing outside is a good seed bed. This can be a separate nursery bed or any part of the garden where you want to sow the seed in situ. The ground should be well prepared with all weed, particularly perennial varieties, removed. Organic material should be incorporated into the soil as it is dug. The prime consideration is a fine tilth, something that gardeners have sweated over for generations. A fine tilth means that the dug soil must be broken down into fine particles, not quite as fine as dust but as near as can be achieved with a rake.

If the ground is dry, the plot should be well watered several hours before sowing takes place to allow the soil to take up moisture.

Broadcasting

Essentially there are two ways of sowing outside: by broadcasting or in drills. The former method was adopted by farmers before the advent of mechanised seed drills. It simply involves scattering seed over the prepared soil and lightly raking it in. In gardening terms this is most commonly used for sowing grass seed for lawns (probably the most likely candidate for sowing outside!). It is also used for sowing annuals over a particular area in a border. The difficulty with this method is in producing an even spread of seed. Unfortunately most of us use this method so seldom that we do not acquire skill in its execution. One way to help is to lay out a grid with string or by scratch marks on the soil and applying a prescribed amount of seed to each square (a handful, for example, or a more precisely measured amount if necessary). Some seed (such as grass seed) can be easily seen when it is cast, whereas others benefit by being mixed with a light or dark sand which will give an indication of the evenness of the spread when both are scattered together.

Drills

The other method, most widely adopted by gardeners, is to sow in drills or rows. Here it is a question of marking out a row with a piece of string and then inscribing a shallow drill with the corner of a hoe or a sharp stick. The seed is sown thinly in this drill and then a thin layer of soil is drawn back over the row. It is essential to label the row, partly to know where it is in order to facilitate weeding and partly so that you know what the row contains. With some seed, such as parsnips, where the plants will be thinned out to a reasonable distance apart, say 9in (23cm), it can be station sown. This entails sowing three seeds every nine inches leaving a gap between each group. When the seed germinates two are removed leaving the strongest. With varieties that are slow to grow, again such as parsnips, it is possible to grow a faster germinating plant, radishes for example, in the gaps between the groups. This not only allows the gardener to get the maximum from his space, but also gives a good indication of where the rows lie, making it easier to hoe between them without accidentally disturbing the slower seed.

If, as is often the case, the soil is heavy and very difficult to break down, it is possible to draw out a deeper row and fill it with a layer of compost, either from the compost heap or potting compost. The seeds can be sown on this and then lightly covered with a further layer. This technique can also be applied in areas that are dry as this compost will more readily hold the moisture and help the seed germinate. Peat can also be used but it should be moist and kept moist (not a very easy task in the open).

One of the main problems in the open is keeping household pets and birds from rolling in the fine soil. Disturbance of this kind can be avoided by covering the seed bed with netting, or by temporarily laying down a number of pea sticks on their side over the drills.

The other problem is moisture. Since the seed is lying just beneath the surface it is in that area which dries out very quickly and an eye should be kept on it, water with a fine rose watering-can if it should become parched.

Earlier crops can be achieved by covering a seed row with a glass or polythene cloche. It also enables more tender plants to be sown before the risk of frost has completely passed. There are, however, many flowering plants, both annual and perennial, and vegetables that can be sown in the autumn and which will happily overwinter in the open.

Richard Bird is an author of a number of books covering different aspects of gardening.

Source of article
Growing From Seed - Autumn 1990 Vol. 4 Number 4
© The Seed Raising Journal from Thompson & Morgan