Propagating Plants: Sowing Seeds and Transplanting Seedlings

sowing seeds

If you have ever sown seed across an open plot and seen it all disappear from the depredations of pests, birds, frosts or droughts, the advantages of a special nursery bed where the soil is fine and easily tended and the seedlings fairly close together for inspection will be obvious to you. You will find that a raised bed is better drained and warmer than flat soil because it has a greater surface to catch the sun’s heat. Make it roughly the same shape as an upturned roasting tin. Site it in a place which gets a little shade but which is not actually shady all day. Its size depends upon your garden but it needs to be at least a yard square or more.

I have my own nursery bed inside the cage which covers my vegetable garden. You will find that you can protect your seedlings from birds (or from cats) by taking a piece of small mesh wire netting and folding it down the centre to make a tent. Either make it longer than you need and fold the ends over to close them or cut two triangles to fit. You can fix them in position by pushing bamboos through them and so peg them into the ground or, alternatively, you can hook the wire ends round each other. I use clothes pegs to secure them. If you wish to cover this tent with polythene for the purpose of keeping frost out, this also can be secured by using pegs.

Find some good soil for your seed bed. I always take the precaution of making a layer of John Innes seed soil on the surface and I find this worth while, for it does seem to give the plants a better start, and the weeds are kept at a minimum. It should be so fine and of such a good texture that you can draw drills very easily. You will not need a real line but you will need a guide. You can use your rake handle or a cane. If you have made a large bed, use a plank to walk on as you make the rows but remember that two or three small beds are easier to manage than one large one.

Put down slug pellets if you find these pests a nuisance. Place them under a stone if you have pets. Strand cotton over the bed if you are troubled by dust-bathing sparrows or, alternatively lay fine twigs over the soil surface. These will also, like the wire netting I mentioned earlier, give shade.

Use this seed bed for biennials, perennials and some vegetable plants such as brassicas, leeks and lettuce.

Generally speaking, a large seed needs to be buried twice its own depth. Small seed should be just covered to prevent it blowing away. Vegetable seeds and flowers specially grown for cutting are sown in drills.

For these the ground must first be dug, in the autumn if possible. If you are sowing seeds in borders among other plants, use a small border digging fork. If it is not advisable to dig deeper than an inch or two, then merely scratch the surface to take the seed and import soil to cover it. Alternatively, you can use fine silver sand to cover the seed. This will also provide a marker and remind you where the seeds are sown.

Soil surfaces must be dry for seed sowing although the soil must be moist below. If your shoes stick to the soil it is too wet for seed. On large areas first rake the soil level walking backwards as you do, so covering foot marks and bringing with you all old roots, bits of stick and large stones.

Incidentally, if you mark the handle of your rake in feet and six inch lengths you have a handy measure.

To make a drill, use a draw hoe, one with a crook neck. Hold the handle, stand at one end of the line, tilt the hoe letting its back run along the line and draw a furrow or a drill through the soil. Avoid making this drill too deep for tiny seeds, but remember that the furrow is deceptive and is twice as deep as the drill, because of the ridge of soil on each side. But if seeds are not sown deep enough, they are liable to be raked to the surface later. Sow small seeds from the packet (mix them with sand if they are very small), and large seeds from a few poured in a dish and scattered by hand.

Always mark each end of a drill with a cane or stick before removing the line after sowing. Take the rake and, using the back, gently pull it along one side of the drill to cover the seed. Treat the other side the same way to level the soil again. Walk down the row pressing the soil lightly with your (low heeled) shoes. But do not leave it tramped hard like this. Just scratching the surface (if you go too deep you will bring the seeds to the surface) walk backwards and rake the soil, herring-bone fashion, until it looks groomed again. Do not walk on it again until the seeds show through. Place a label against one of the sticks. Make the drill for the next row using the sticks at each end of the row as markers.

The difference between a plant that has been given plenty of room and one which has to fight for its existence is really remarkable, so if you have sown seeds of annuals do not let them remain crowded. You must thin them out as soon as they are one inch high or large enough to be handled. Although there are exceptions, usually the seedlings can be planted somewhere else, so need not be wasted.

Wait for a shower so that the soil is moist before lifting the seedlings. Roots are covered with fine hairs which cling to the soil particles through which the plant takes its soluble food from the soil, so disturb the roots as little as possible. The more soil you take with the plant the fewer hairs are broken and the less damage you do and so give less shock to the plant. The smaller the shock the quicker will the plant get away in its new home. One reason why it is good to mix peat in the soil is that the root hairs cling well to it.

First thin out so that the plants clustered in a group are all about three inches apart every way. If you thin more than this at first and a plant gets eaten or damaged you will have to fill in instead of thinning out! Remove more plants when they begin to touch each other.

For very small seedlings an old kitchen fork will raise them out with little damage. Don’t let those you want to move lie in the sun but make the interval they are out of the soil as short as possible. If you want to give them or take them away slip them in a plastic bag, and close the end.

If you want merely to thin not to transplant them, either cut very crowded ones out with a pair of scissors or pull them out between finger and thumb. Firm the soil after thinning.

Seeds Failing to Germinate

If some of your seeds fail to germinate, it could be that they are of the type that needs to be subjected to frost to break their dormancy. Place the seed trays outside in a light place out of direct sunlight. Cover them with a pane of glass until after Christmas, then remove the glass and leave the cold weather to get at them. Some seeds will take at least two years to germinate in this way, so do not despair and chuck the compost out.

This process is known as stratification, but do not let that put you off. Seeds from lilies, paeonies, hellebores and hollies seem to enjoy this cold comfort. A little extra sand in the compost and a layer of grit over it helps to keep the drainage going. Some fleshy seeds, such as those of lilies, do not like being dried out and should be sown into the compost straight from the matured seed head.

27. September 2010 by Dave Pinkney
Categories: Plants & Trees, Propagating | Tags: , | Comments Off on Propagating Plants: Sowing Seeds and Transplanting Seedlings


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