The drainage may consist of any coarse material, such as old broken pots, small stones, pieces of charcoal, and the like, over which should be placed small broken sod or a little moss to keep the dirt from washing through and eventually stopping up the crevices through which the excess water should flow.
A safe rule to follow in first potting the majority of house-plants, is to use one-third turf-loam, one-third leaf-mold or decayed leaves, and one-third sand, thoroughly mixed. Reduce the amount of leaf-mold and sand at successive pottings, adding a little well rotted manure, until, when the plants have been potted in 6-inch pots, at least four-fifths of the soil is turfy loam. Press the soil firmly in the pot and around the plant. Never fill the pot level full of soil, else the plant cannot be watered.
PRICKLY POPPIES, or ARGEMONES, are hardy annuals, with large, bluish striking foliage and yellow flowers. They are easily grown in a warm soil and sunny exposure. Sow the seeds where the plants are to stand. Thin to 12 to 18 inches apart. They grow 2 feet high.
PRIMULAS, or PRIMROSES, are of various kinds. One of them is the Auricula (which see). Others are hardy border plants. The true or English cowslip is one of these; also the plants commonly known as Polyanthus. Hardy Primulas grow 6 to 10 inches high, sending up trusses of yellow and red flowers in early spring. Propagated by division, or by seed sown a year before the plants are wanted. Give them rich, moist soil.
The Primula of the winter-garden is mostly the _P. Sinensis_ (Chinese Primrose), grown very extensively by florists as a Christmas plant. With the exception of the full double varieties, it is usually grown from seed. The seed sown in March or April will make large flowering plants by November or December, if the young plants are shifted to larger pots as needed. The seed should be sown on the flat surface of the soil, composed of equal parts loam, leaf-mold and sand. The seed should be pressed down lightly and the soil watered carefully to prevent the seed from being washed into the soil. Very fine sphagnum moss may be sifted over the seed, or the box set in a moist place, where the soil will remain wet until the seeds germinate. When the plants are large enough they should be potted separately or pricked out into shallow boxes. Frequent pottings or transplantings should be given until September, when they should be in the pots in which they are to bloom. The two essentials to successful growth through the hot summer are shade and moisture. Height 6 to 8 inches. Bloom in winter and spring.