168 PLANT PROPAGATION 
and popular genus, including seeds, cuttings, layers, 
and grafting. The minute seeds are sown in well- 
drained pots or pans of sandy peat, the surface is made 
smooth and level, watered, and allowed to drain. The 
seeds are then scattered thinly and very lightly covered, 
A cold frame is a suitable place for the hardy sorts, but 
a higher temperature is needful for stove and green- 
house kinds. When big enough to handle, the seed- 
lings are pricked off in pans of similar compost and 
shaded. 
_ Cuttings are made of moderately ripened shoots in- 
serted in pots of sandy peat in a close case, with a 
slightly higher temperature than that in which they 
have been growing. When callused a little, bottom heat 
assists the formation of roots. Side-grafting on suitable 
stocks of free-growing kinds is done in autumn, but 
greenhouse hybrids, such as Princess Royal, succeed 
best when worked in winter. They require to be kept 
in a close case and shaded until a union is effected, and 
afterwards gradually inured to more ventilation. Layer- 
ing of hardy sorts is considered to be best done in 
October or November. 
RHUBARB.—Division of the roots with a clean, sharp 
spade can be effected from November to February, at 
least one crown or bud being attached to each portion, 
and this is the quickest method of propagating. Seed, 
if sown in March outdoors, will, with high cultivation, 
produce stems fit for use in one or two seasons. 
Ruus.—Some of the hardy Sumachs are very orna- 
mental and may be propagated by ripened shoots made 
into cuttings in September, also by layering branches in 
autumn. Such species as R. glabra laciniata can be 
readily increased by stout root-cuttings, 3 inches long, 
