Sometimes it will be beneficial to moisten the foliage of plants without wetting the soil. Just after repotting and in fighting plant lice, red spider and other insect enemies (see Chapter XVII) this treatment will be necessary. A fine-rose spray on the watering-can may be used but a rubber plant-sprinkler costing about sixty-five cents, will be very much better, as with it the water will be applied in a finer spray with a great deal more force and to either the upper or under surface of the leaves--a point of great importance.
Plants growing in windows, where the light strikes them only, or mostly, from one side, should be frequently turned to prevent their growing one-sided.
Also do not hesitate to use knife, scissors and fingers in keeping them symmetrical and shapely. One of the greatest mistakes that amateurs make is in being afraid to cut an ungainly or half leafless branch. Instead of injuring a plant, such pruning frequently is an actual benefit.
If neglected, dust will quickly gather on the leaves and clog their pores, and as the plants have no way of breathing but through their leaves, you can see what the result must be. Syringing, mentioned above, will help. They should also be wiped clean with a soft dry cloth, especially such plants as palms, rubbers, Rex begonias. Do _not_ use olive oil or any other sticky substance on the cloth. Always remove at once any broken, dead or diseased leaf or flower. Do not let flowering plants go to seed: nothing else will so quickly bring the blooming period to a close.
Do not try to force your plants into continuous growth. Almost without exception they demand a period of rest, and if you do not allow them to take it when nature suggests, they will take it themselves when you do not want them to. The natural rest period is during the winter. During this time a _very_ little water will do and no repotting or manuring should be attempted.
It is, however, desirable in some cases, as with many of the flowering plants, to change the season bloom, as we want their beauty during the winter. In such cases they should be _made_ to rest during the summer, by withholding water and keeping them disbudded.
Many beginners get the idea that as soon as any plant has filled its pot with roots it must be immediately shifted to a larger one. While this is as a rule true with small plants, being grown on, it is not at all true of mature plants, especially those wanted to bloom in the house. When a shift has been given, at the beginning of the growing period, no further change should be necessary during the winter. It will, however, be well, if not imperative, to furnish food in the form of liquid manures when the soil in the pot has become filled with roots. It should be applied from one to three times a week--the former being sufficient for a plant showing ordinary growth.