PLANTS from SEEDS

THE easiest way of propagating a large number of plants is by sowing seeds in the open garden. This is possible with such plants as most vegetables and salads, hardy annuals, some half-hardy annuals, biennials, hardy perennials and many flowering shrubs and trees. The main requirement is a properly prepared seed-bed. This preparation starts with digging the ground over either in the winter or the spring. It is usually left to settle down for a week or two after this, although this is not absolutely essential if time presses and you are anxious to get on. In any case, after the soil has been dug it needs forking over to break down the clods into smaller lumps. The next step is to tread all over the plot to crush these lumps down further still. These operations should be carried out when the ground has dried out fairly well after the winter. Light soils dry out quickly and it is usually possible to gel on with preparing seed beds on these quite early in the year. But the heavier soils retain moisture much longer and it is usually late February or March before they have dried out sufficiently for them to be broken clown finely enough. Clay soils are often even more difficult and sometimes the moment for making a seed-bed has to be judged exactly.

On these soils it is usually-possible to begin work after a period of drying winds and sunshine in the spring. If work is started too early the ekiy is too sticky. If it is left too late it tends to dry hard like a brick and is then very ‘difficult to break down properly. But between these two states there is usually a period when even clay will break down with the aid of a two-pronged Canterbury hoe, the back of a stout fork and the gardener’s boot. Whether the clay is in the right state or not can usually be judged by kicking at the drying clods. If they crumble easily then it is time to get on with making a seed bed. If they fail to crumble then ii is necessary to wait a little while longer.

After the plot of ground has been well trodden over, the next step is to break the soil down even further. This is called ‘making a fine tilth’ and is best done by raking, first one way and then another. This will also help to level the plot, while the act of walking all over it when raking helps to break up the lumps of soil. If the soil is very lumpy it often pays to rake it over first with a wooden hay rake before tackling it with an iron-toothed rake. This will remove the larger lumps to the edge of the plot where they will dry out more and may be broken down later by treading. Raking will also remove stones, weeds and other debris.

The aim should be to break the top few inches of soil down to fine grains and a fair amount of raking and treading may be necessary before it arrives at this state. Onions need a firmer bed than other seeds and on very light soils it helps to roll the plot over once with a light roller. On heavier soils this should be omitted as it may tend to consolidate the soil too much and exclude air. Rolling on light soils is also helpful when the ground is being prepared for sowing grass seed. This is not only to break down the surface soil ready to receive the seeds, but also to show up any inequalities in the surface which can then be put right before seed sowing.

Seeds need three things to enable them to germinate properly. These are moisture, air and warmth. There is usually-enough moisture in the soil for the seeds to germinate, although if sowing has to be done in droughts then the soil should be watered first. Air is present in the soil, filling the tiny spaces between tfoe particles of soil, but much of it may be forced out if the soil is too heavily consolidated. For this reason it is better to keep off heavy clay soils until they are ready, to break down. Warmth is provided by the sun when seeds are sown outdoors. It is often found that seeds will not germinate properly if they are sown too early before the soil has had time to warm up. However, this can be overcome to a great extent by putting cloches over the soil a week or two before sowing. This makes a good deal off difference to the soil temperature. Most seeds germinate best in darkness and this is why seeds are covered with soil after they have been sown.

ANNUALS

THE correct definition of an annual is ‘a plant that completes its life-cycle from seed to seed and dies in one favourable season’. The ‘favourable season’ may be quite short – a matter of a few weeks. During the rest of the year the plant survives in the form of seeds.

But for practical purposes the gardener regards an annual as a plant that is raised from seed, grows to maturity, flowers, produces seeds and dies naturally, not through the effect of frost, within the period of a year.

A hardy annual will withstand a certain amount of frost, sometimes of considerable severity-larkspurs, sweet peas and calendulas are good examples. A half-hardy annual is susceptible to damage byfrost – some varieties bring more liable to damage than others, such as snapdragons and petunias. Tender or greenhouse annuals are plants that need a climate rather warmer than we have as a rule in Britain and so need to be grown in a greenhouse or conservatory. It is often possible, however, to put them outside for a few weeks during the warmest part of the summer.

BIENNIALS

A BIENNIAL plant is one that takes two growing seasons to grow from seed to maturity and then dies. Forget-me-nots (Myosotis) and Sweet Williams (Dianthus barbatus) are good examples. Seeds are sown in May or June, the young plants are transplanted into some odd corner and then put in their flowering positions during the autumn. They flower in the following spring or early summer.

Gardeners are mainly concerned with the hardy biennials of which there are a great many – Canterbury Bells (Campanula medium), the Chimney Bell-flower (Campanula pyramidalis), the Siberian Wallflower (Cheir-anthus allionii), the Sweet Rocket (Hesperis tristis), Honesty (Luii-aria annua) and others.

There are half hardy biennials plants that take two seasons to mature from seed but which need greenhouse protection at all times. But the gardener need not worry about these. It is the group of hardy biennials that is so useful for the garden.

PERENNIALS

THE simple definition of a perennial is a ‘plant with a life of at least three seasons’. This of course would include trees, shrubs, bulbs, and many border plants such as paeonies, michaelmas daisies and the like. But when gardeners use the term ‘perennial’ they tend to think of rock garden plants such as thrift, aubrietas, dwarf phloxes, perennial . candytuft and so on. They also think of the herbaceous perennials grown in borders – delphiniums, geums, lupins and the like. An ‘herbaceous perennial’ is a plant with soft or non-woody stems that usually dies down to the ground each year.

The herbaceous perennials are tremendously valuable in the garden. Most of them are very hardy, they suffer little from pests or diseases, and many of them are very long-lived. Oriental poppies, perennial gypsophila and paeonies will live for 40 or 50 years. Most of them will grow in almost any soil and are easily increased by dividing the roots.

A common mistake is to sow too deeply. As a general rule seeds outdoors should be sown at a depth which is about two or three times their own diameter. With small seeds this is difficult to estimate and it is usual to sow them about | in. deep. Large seeds such as peas and beans are sown about 2 in. deep. But some account should be taken of the type of soil’and the time of year. For instance on heavy clay soils it is better to sow less deeply. On any kind of soil if such things as broad beans are being sown in autumn to stand over the winter then they should be sown more deeply than they would be in the spring. It is sufficient to sow very fine, dust-like seeds on the surface and either lightly rake soil over them or scatter a little soil over them through a fine sieve. It is essential to sow seeds thinly but this is difficult where liny seeds are concerned. It helps to mix the seed with an equal quantity of clean dry sand. This helps to spread the seed more cvenh and thinly.

Seeds are sown either broadcast or in drills. Grass seed is scattered broadcast and other seeds often sown in this way are radishes, mustard and cress and annual flower seeds. The difficulty with sowing broadcast is that it is not easy to space the seeds out properly and they often come up much too thickly and the seedlings have to be drastically thinned or they are too overcrowded. Also hoeing. Which is necessary to keep down the weeds which compete for food, water, light and air, is easier between rows. For these reasons most other vegetable5 seeds, biennial and perennial flowers and seeds of trees and shrubs are usually sown in straight rows.

For this purpose ‘drills’ shallow depressions in the soil are made with some instrument such as the corner of a hoe. The point of a dibber or merely a pointed stick. A taut garden line is used. Close to the soil, to ensure that the drill is straight. Deeper drills for large seeds are often taken out with a draw-hoc or even the spade and the seeds are spaced out individually before the soil is returned over them.

When sow ing in these drills the corner is torn off the seed packet and sonic seed is poured into the palm of’the left hand . If the seeds are small, pinches of seed are taken between the thumb and forefinger of the other hand and as these are rubbed lightly together seed falls into the drill (airly evenly as the gardener moves his hand along ihe drill. Large seeds such as those of peas and beans may be sown individually. Some seeds are very light and chaffy and liable to blow about in the wind, so it is wise to choose a calm day for sowing these. Parsnips are an example, with which it is usual to sow two or three of the large but light seeds in groups about 9 in. apart and thin out the weakest seedlings later. With most seeds it is sufficient to cover them by raking the soil back over them with the back of the rake. Any watering of the drills which may be needed in dry weather, should be done before sowing. If done afterwards it may compact the soil too much oxer the seeds, making it difficult for the seed leaves to force their way through the soil, or it may wash fine seeds too deeply into the soil.

After sowing, and before taking up the garden line and moving on to the next drill, place a clearly written label in position at the end of the row. It helps if this gives the date of sowing in addition to the name of the plant.

Some protection from birds may be necessary. Pea guards placed along the rows are effective. Black cotton stretched across newly-sown seeds will usually deter most birds. Otherwise bird-scarers of various kinds are available which cither make a noise or flap or flash in the breeze.

Sorry, comments are closed for this post.