Most of the plants used for flower gardens and lawn beds come under the three following classes: (1) Those grown from seed; (2) those grown from cuttings; (3) those of a bulbous nature.
Almost all of the first group are sown in the spring in flats in the greenhouse. Two important exceptions, however, are pansies and English daisies (_Bellis perennis_). They are sown early in the fall, as already described, and the plants wintered over in a frame or protected outdoors. For the retail trade they are put up in small boxes or "pansy baskets" made for the purpose. While small plants, just beginning to bloom, are the best, it seems very hard to convince a customer of it and they will often choose a basket with four or five old plants loaded with bloom in preference to a dozen small ones.
Asters, alyssum, balsams, candytuft, celosia, coleus, dianthus (pink), lobelia, mignonette, petunias, phlox, portulaca, ricinus, salvia, verbenas, vinca, roses, zinnias, may all be started from seed. The greatest secret of success is to keep the plants from crowding, and keep pinched back to make bushy plants. Salvias and coleus are the tenderest of these plants. The others can go out to the frames, if room is scarce, as soon as the weather becomes settled.
The method of choosing and rooting cuttings has been outlined in a previous chapter (see page 29). In greenhouse work the main difference is that they are taken in much larger quantities. For this reason it is usually convenient to have a cutting bench instead of the flats or saucers used in rooting house plants. The bench should be three or four inches deep, filled with medium coarse, gritty sand, or a substratum of drainage material. If possible, have it so arranged that bottom heat may be given--this being most conveniently furnished with pipes under the bench boxed in. (The temperature required for most cuttings will be fifty to fifty-five in the house with five to ten degrees more _under_ the bench.) The cutting bench should also be so situated that it readily may be shaded, as one of the most important factors of success is to prevent the cuttings from wilting at any time--especially just after placing in the sand. After rooting, the cuttings are put into small pots or flats as already explained.