separate.  For pot-culture the single varieties are best.  Put three bulbs in a 5-in. pot and six in a 6-in. one, and treat in the same manner as the Hyacinth.  They may, if desired, be forced as soon as the shoots appear.  When required to fill vases, etc., it is a good plan to grow them in shallow boxes, and transfer them when in flower to the vases or baskets.  By this method exactitude of height and colouring is ensured.  Tulips are divided into three classes:  (1) Roses, which have a white ground, with crimson, pink, or scarlet marks; (2) Byblomens, having also a white ground, but with lilac, purple, or black marks; and (3) Bizarres, with a yellow ground having marks of any colour.

Tunica.—­Same treatment as “Dianthus.”

Turkey’s Beard.—­See “Xerophyllum.”

Turnips.—­To obtain mild and delicately-flavoured Turnips a somewhat light, sandy, but deep, rich soil is necessary.  For a first crop sow the Early White Dutch variety in February or the beginning of March on a warm border.  For succession sow Early Snowball at intervals of three weeks until the middle of July.  For winter use sow Golden Ball, or other yellow-fleshed kinds, early in August.  Thin each sowing out so that the bulbs stand 9 in. apart.  To ensure sound, crisp, fleshy roots they require to be grown quickly, therefore moist soil and liberal manuring is necessary, and the ground kept free from weeds.  If fly becomes troublesome, dust the plants with quicklime early in the day, while the dew is on them, and repeat the operation as often as is necessary.

Tussilago Fragrans (Winter Heliotrope).—­A very fragrant hardy perennial, flowering in January and February.  It will grow in any good garden soil and bears division.  Height, 1 ft.

Twin Flower.—­See “Bravoa.”

U

Ulex Europaeus Flore Pleno (Double Furze).—­This elegant, hardy, evergreen shrub likes a rich, sandy soil, and may be increased by cuttings planted in a shady border and covered with a hand-glass.  Height, 5 ft.

Umbilicus Chrysanthus.—­This little Alpine plant should occupy a warm, sheltered, and dry situation, and be protected with an overhead screen in wet seasons.  The soil it most enjoys is a mixture of peat and coarse sand.  Its procumbent stalks emit roots.  This new growth may be transplanted in the spring or early summer months.  Height, 6 in.

Uvularia.—­Beautiful hardy perennials, producing drooping flowers from May to July.  They succeed best in a light, sandy soil, and may be increased by dividing the roots.  Height, 1 ft.

V

Vaccineum Myrtillus and V. Uliginosum.—­Attractive deciduous shrubs.  They require to be grown in peat or very sandy loam.  In April or May they produce flowers.  They can be increased by dividing the creeping roots.  Height, 1-1/2 ft.