154 PLANT PROPAGATION 
seed should be steeped in water for twenty-four hours, 
then sown about the end of March in a warm frame, 
and a few of the seedlings potted up and grown on for 
planting outdoors when danger of frost is past. 
Nicotiana (Topacco Pxiant).—The favourite sweet- 
scented N. affinis and other kinds are raised from seed 
sown in geftle heat in February and treated as other 
half-hardy annuals for planting out at the end of May 
or early in June, according to the weather. 
NIGELLA (Love-1n-A-Mist, DEvIL-IN-THE-Busu).—The 
pretty N. damascena, N. hispanica, and the attractive 
variety Miss Jekyll should be sown where intended to 
flower in March or April and the young plants thinned 
out to about 6 inches apart. 
Nuts.—For planting in woods, the Common Hazel- 
nut is raised from seed that have been stratified and 
protected from mice and sown in nursery rows in 
spring. To insure the production of approved sorts of 
Filbert and Cobnuts, rooted suckers are taken off in 
autumn, shortened back, and planted. Layers are also 
pegged down in autumn and winter, and become suf- 
ficiently well rooted, if covered with a few inches of soil, 
for removal the following autumn. Whip-grafting old 
trees of inferior kinds with improved varieties is done in 
February and March, 
NympH2@A (Water Lity).—Propagation of these 
lovely aquatic plants can be effected by dividing the 
tubers just as growth is about to start, also by seed 
sown in pots of loam and immersed just below the 
surface of the water in spring. As the seedlings grow 
and increase in strength the water should be gradually 
raised, or the pots sunk more deeply, with the leaves 
floating on the surface. 
