There are some choice alpine plants that cannot be cultivated to the best advantage in the open in our uncertain climate. To say that they are choice does not necessarily mean that they are delicate, but that the blooms of many are apt to be spoilt by inclement weather; it is to these subjects that the Alpine House affords protection while they are in bloom; it will also prolong their season of flowering.

Most of the inmates can be brought on during the summer in pans sunk to their rims in ashes or sand in the open, or in sunny frames, until about to flower, when they should be transferred to the house, to be removed again to the open after flowering. After the beginning of October all the plants should be housed in a frostproof frame and must be removed to the cold house as the blooms become visible.

While the plants are in the frame ample air must be provided, but frost must be excluded. The choicest saxifrages, however, are usually kept in the house the whole year through, as their neat and compact foliage is pleasing and interesting even after the flowers are over, and does not get ragged and untidy.

Ventilation And Shading

If a span-roof type of house is used, it will be found most convenient to have a centre path and stagings, that will raise the plants up near the glass, down both sides; the plants will then be easily accessible.

The stagings should be covered with a half-inch layer of shingle or fine ashes.

Compost And Potting

Most alpines thrive in a gritty, well-drained soil. Two-thirds fibrous loam and leaf-mould with one-third coarse, gritty sand makes an excellent compost for most of them.

Many of the finer saxifrages like a little splintered limestone or some old lime rubble, similar to that used in carnation culture, in their soil. Individual tastes must be studied. Pot-up in pans from six to nine inches in diameter and about five inches deep; and since ample drainage is required, place two and a half to three inches of broken crocks in the bottom of the pans for plants like the Androsaces and the Saxifrages.

For subjects of a more vigorous nature and for bulbs, one inch of crocks will suffice.

Watering

Alpines require ample water during their growing period and while in bloom; but care must be taken to see that the drainage is adequate, for a stale, stagnant soil is the alpine's greatest enemy. Plants will need most water in the spring and summer. Water at least once a day, sometimes twice, at this season.

Dormant plants and those freshly potted are best kept rather dry until growth begins.

A watering once a week, or even less frequently, will suffice for most plants in winter time; but the soil must be prevented from becoming dust-dry.

In the summer the watering should be done when the sun's heat is at its lowest, early in the morning or in the early evening, but in spring, late autumn, and in winter it is essential to water in the morning, so that excessive moisture may have drained off before the evening, otherwise there is great liability to "damping-off."

Many plants, and especially those that have not recently been repotted, will be the better for a watering with mild liquid manure every ten days while the buds are forming. This must be discontinued as soon as the flowers are out.

These are just a few guidelines for alpine plants which could benefit from an alpine house. It is well worth your while to expand your gardening with the use of such a house. Good luck!