When these are ready, take the seed in your hands and carefully dribble it in as evenly as you can. When you have finished, rake the earth smoothly over the trenches again, and pat it gently in place. You should always put a stick or a label where you sow seed or set bulbs, as it is easy to forget what one has done, and put things on the top of each other. In favourable weather some of your seedlings will show their seed-leaves in ten days or a fortnight, but others will take longer. The first pair of leaves are what botanists call cotyledons, and those that come after are unlike them. You will soon get to know both the cotyledons and the other leaves of the plants you grow. You can often tell your seedlings from weeds by observing a whole colony of new-comers exactly alike, where you have placed a stick or a label. As soon as you can handle them they will want carefully thinning, and when you find out how troublesome it is to thin a patch of Poppies properly, for instance, you will understand why we advise you to mix all your small seed with sand, and only to put a pinch into the ground. Firms that sell penny packets of seed tell you that there are two thousand seeds in some of their packets. Poppy seeds nearly all come up, and a well-grown plant should have a foot of soil to itself. So if you made a hedge of poppies all along one side of your border, you would use seven seeds out of two thousand. All gardeners sow more seeds than they mean to use, because they must allow for accidents and insects, and they expect to do some thinning. But the ignorant gardener invariably sows his seed too thick, and leaves his seedlings too close together; so he gets a crowd of starved, stunted plants that do not flower well, and are soon over for the year. You should begin by leaving three inches between your seedlings, and end by giving most of them a foot apiece. Some will require more room, some rather less, and the best way to please them is to watch them constantly, and make sure that each little plant has room to expand. In thinning seedlings you must be most careful not to disturb the roots of those you wish to leave, and when you have sown too thickly this is difficult. Some seedlings will bear pricking out in another part of the garden; some, such as Wallflowers, actually like it; while others will not stand it at all. You should do your pricking out in showery weather.