Weigelia.—­Free-flowering, hardy, deciduous shrubs, the flowers being produced in profusion along the shoots in April, and varying in colour from white to deep crimson.  The plants will grow in any soil, and require no special culture.  All the varieties force well, and may be increased by cuttings.  Height, 6 ft.

White Scale.—­See “Scale.”

Whitlavia.—­A hardy annual, needing no special treatment.  It may be sown in autumn, and protected during winter in a frame, or it may be raised in spring in the open ground, where it will bloom in June.  Height, 2 ft.

Whortleberry.—­See “Vaccineum.”

Wigandia Caraccasana.—­A stove deciduous shrub which thrives best in a mixture of loam and peat.  Cuttings in sand will strike if placed under glass and in heat.  It flowers in April.  Height, 10 ft.

Windflowers.—­See “Anemones.”

Winter Aconite (Eranthis Hyemalis).—­This is one of the very first of flowers to bloom, being in advance of the Snowdrop.  In the bleakest days of winter this little flower covers the ground with its gilt spangles.  Plant in early autumn.  Any soil or situation suits it, but it does best in a light mould and a moist, shady position, or under trees.  Most effective when planted in masses.  The tubers may remain permanently in the ground, or they may be lifted and divided in summer, as soon as the foliage dies down.  Flowers are produced from December to February.

Winter Cherry.—­See “Physalis.”

Winter Heliotrope.—­See “Tussilago.”

Wire-worms.—­Before using mould for potting purposes it is advisable to examine it carefully and pick out any Wire-worms that are in it.  For the border the best traps are small potatoes with a hole cut in them, buried at intervals just beneath the surface of the soil.

Wistaria.—­This noble wall plant may be abundantly produced, as a long layer will root at every joint.  It will also grow from cuttings of the plant and root.  Though of slow growth at first, when well established it is very free-growing and perfectly hardy.  It may also be grown as a small tree for the lawn or centres of large beds by keeping the long twining shoots pinched in.

Witch Hazel.—­See “Hamamelis.”

Withania Origanifolia (Pampas Lily-of-the-Valley).—­A hardy climbing plant, attaining a height of 20 or 30 ft. in a very short period.  The foliage is small, but very dense and of a dark green, the flowers being white.  It may be raised from seed, and when once established the roots may remain undisturbed for any length of time, merely removing the stems as soon as they are destroyed by frost.

Wolf’s Bane.—­See “Aconite.”

Wood, to Preserve.—­In order to prevent wooden posts, piles, etc., from rotting, dip the parts to be sunk in the earth in the following composition:—­Fine, hard sand, three hundred parts; powdered chalk, forty parts; resin, fifty parts; linseed oil, four parts.  Heat these together in a boiler, then add red lead, one part; sulphuric acid, one part.  Mix well together, and use while hot.  If too thick, more linseed oil may be added.  This composition when dry attains the consistency of varnish, and becomes extremely hard.