The Garden Under Glass

244 THE GARDEN UNDER GLASS Top-dressing with Chemical Manures When top-dressing a plant with Chemical fertilisers it is a good plan to loosen the surface slightly, but if this cannot be done without injuring the roots it had better be left alone. A mere sprinkling of the fertiliser will be sufficient. Better to give it at more frequent intervals than to burn the roots by an overdose. In view of the faet that some of these Chemicals will injure the leaves of plants, it is a safe plan to avoid getting any of it on the leaves, though it is only fair to say that the majority of these patent fertilisers are not injurious. The time to top-dress with fertilisers or with soil and to feed with liquid mantire is only when the pots are well filled with roots. After a dose of Chemical manure, watering should be carefully done, or the manure will be washed over the pots. A Form of Side-dressing A method of adding more soil to plants when they have well taken hold of the other I have carried out successfully with tomatoes. They were grown in a box formed by standing 9-inch planks on end. eight inches apart. When the soil afforded the plants had become well filled with roots I have eased back the planks a couple of inches on both sides, and, after fixing them firmly in place, have filled the space with some good top-dressing soil.