The Garden Under Glass

CHAPTER IX x BEAUTIFUL PLANTS FOR FORCING There are many shrubby plants whicli naturally flower outside in the spring that can by forcing be persuaded to flower much earlier in the greenhouse. Among those most generally used with success are: lilacs, deutzias, staphyleas, spireas, dielytras, roses, azaleas, lilies of the valley, liliums, hydrangeas, violets, Solomon’s seal. Plants which are intended for forcing are best got into their flowering pots early in the autumn, if indeed they have not been left in them through the summer. If they are left exposed to frost it is usually found that they force much better, but to expose the pots to severe frost will mean that many of them will probably become cracked, or at any rate damaged. This can be guarded against by plunging the plants above the rims of the pots in ashes or leaves, or even in ordinary soil. If leaves are available I would prefer them. Then the plants will be safe through-out the autumn and winter, and a few may be brought along at a time as they are wanted. But to take a plant from a frosty atmosphere to a warm house is not a good practice, for no plant relishes such sharp fluctuations of temperature and many will show unmistak-able signs of this resentment. They should be removed from the outside to a cold house for a week, and from this they may be moved into a warm house. As with bulbs, the easiest männer is to move a few plants round each week or each fortnight. Gentle forcing can be done at 121