Plants for flowering early in the spring outdoors should be treated in the same way during summer, and wintered in the cellar, as directed above. Take up to the light any time after first of March in the spring, but be careful to harden off before setting outside.
The varieties of the hydrangea are several, some being entirely hardy farther north than New York, but the sorts best for house and tub culture are not. Most of them will come through some winters, but it doesn't pay to take the chance.
H. Hortensia Japonica is the blue flowering variety; the color will depend much, however, upon the soil. To make sure of the color, dissolve one pound of alum in two quarts of ammonia, dilute with twenty gallons water and use as a liquid fertilizer. Thomas Hogg is a beautiful pure white, quite hardy. H. h. Otaksa, pink, is one of the most popular.
Lantana—Easily grown flowering shrub, trailing in habit, with small flower clusters of white, pink, red, yellow or orange. New dwarf varieties best for pot culture. Cuttings root easily. I have never cared for this plant, and its odor is not pleasant to most people.
Lemon—The best lemon for house culture is the Ponderosa, or American Wonder, of comparatively recent introduction. Most florists now have it. Easily grown and a very attractive plant. The fruit is good to use.
Lemon Verbena (Aloysia citriodora)—Many people consider this the most delightfully fragrant plant grown. Certainly no window garden should be without it. Early in September cut back old plants, if in the garden, and pot up. New growth will quickly be made. Plants kept in pots should be rested in early winter by keeping dry and cool. Spring cuttings root easily.
Oleander—A beautiful old-time favorite, with fragrant blossoms of red, pink, yellow or white. Give a very rich soil and plenty of water when growing. Rest after flowering. Cuttings are rather hard, but will root with care.
Orange—There are several sorts suited to house culture, and they should be more frequently tried, as a well grown plant will have flowers, green fruit and attractive golden oranges almost all the time—to say nothing of its foliage beauty and delightful fragrance. Their rest period should be given during November, December and January.
Otaheite Orange is the one most commonly grown for house culture, and while the fruit is of no use for eating, it has the more valuable advantage of remaining on the tree (which is eighteen to twenty-four inches high) for months. Satsuma is another good sort. Kumquat (Citrus Japonica) is also very attractive.
Reinwardtia (known usually as Linum trigynum)—Another attractive flowering shrub, with light or bright yellow flowers. Cuttings will root with bottom heat in April. L. tetragynum is a companion variety.