Prímulas, or Primrose, both Chinese and European, delight in an airy exposure; but the sun destroys the beauty of their flowers by making the colours fade.
Caméllias. Many of them will be in perfection. See Green-house this month for a description of the finest varieties. Do not let the sun shine upon the blooms. Those that are done flowering, will, in small pots, require to be repotted. The Cálla or Æthopian water-lily, when in flower, ought to stand in saucers with water.
The Hyacinths that are in glasses must be regularly supplied with water. The roots will be very much reduced by this method; therefore, when the bloom is over, if possible plant them in the garden, or bury them in pots of earth, to ripen and strengthen the bulbs. They will take two years with good encouragement, before they can satisfactorily be again flowered in glasses, and properly they ought not be allowed to bloom next year. Those that are done flowering in pots, can be set aside, and the usual waterings gradually withdrawn. Treat all other Dutch bulbs in a similar manner.
[Hot-House.]
APRIL.
Where the Hot-house has been properly conducted, the plants generally will have a vigorous and healthful aspect. An error frequently arises in the conducting of these departments, by inexperienced operators being ambitious of outstripping their competitors. They keep the house in a very high temperature, and admit little or no air. Where such mode has been pursued, the plants will have got over their first growth, and the foliage look yellow and decaying, thus throwing the plants into a state of inactivity, when nature herself commences her most active movements. The temperature should not be under 60° nor much above 75°, without admitting a little air by the top lights. It will not do yet to give air by the front sashes, the wind being cool, and a current in the house would be hurtful. The sun is not so powerful but the heat can be kept down by the air given from above. In very cold cutting winds, though the effects of sun heat be great, admitting of much air may be injurious. Whatever error may arise, let it be on the side of caution. However, when high winds prevail, there is little danger of the house becoming overheated by the effect of the sun. Hot-house or tropical plants will not be hurt with 110°, if they are not touching the glass. And if the plants are near the glass generally, the glass should have a coat of very thin white-wash (not lime), where the glass is thin and light in colour; but if it is thick and green, there need be no white-washing.
The plants will need a liberal supply of water every day. We have so constantly cautioned the operator on administering this element, that a repetition here is unnecessary. Sprinkle them well with the syringe or engine in the evenings about sundown, four or five times a week, and strictly observe that none of them are omitted; for where there are such, it is probable they are attacked by the red spider. If any of these are detected, syringe them powerfully morning and evening. Water is most effectual in their destruction, and most congenial to the plants. Give regular fumigations to destroy the green-fly. Wherever there is dust or foulness contracted on the foliage, wash all clean with sponge and water; for on these insects are harboured in such quantities that they, in a short time, would overrun all the plants in the house. Keeping the house constantly clean, the plants clear of decayed leaves and every thing of a corroding nature, and duly syringing them, is the surest method of not being much troubled with insects.
For repotting plants, see next month; except those that you are fostering to a great extent, such as Alstrœmèrias, Calceolàrias, or any herbaceous plants that require great encouragement to make them flower well. These should always be repotted, as soon as the roots come to be round the outside of the ball.