1885.] THE ROCK GARDEN. 351 



THE ROCK GARDEN. 

 ^0. III. 



PEOPAGATION OF ALPINE PLANTS. 



THE cold frame, well glazed, with no drop from the glass, 

 should, according to Mr. Boyd, be the winter home of the 

 rarer alpiues. Kept iu small pots, sunk in ashes, so as to prevent 

 worms from intruding, a large collection will occupy only an 

 ordinary-sized frame. 



As many of these plants do not live long, it is necessary that 

 young plants should be propagated, either by division, cuttings, 

 or by seed. Propagation by division should always be done in 

 spring or early summer, just when the plant has' commenced grow- 

 ing, as at that season there is much less chance of losing the 

 plant by disturbing its roots than at any other. This is a good 

 plan for the stronger growing sorts, but there are many plants 

 where this systeni of propagating cannot be adopted without con- 

 siderable risk. In the case of those plants, it is better to strike 

 young ones from cuttings. This is usually done during summer 

 and autumn, and they are perhaps best protected in a cold frame 

 till they make roots, when they can be potted separately and kept 

 in the frame as duplicates during the winter, and can then be 

 planted out in the rockery to fill up blanks in the spring, when 

 they have just commenced to make growth. But the i:)lan of 

 raising young plants from seed is by far the best when seed can 

 be olitained, as you not only get far more plants, but you get them 

 of a more healthy and vigorous habit. The grower of alpine plants 

 should never lose the chance of collecting what seed he can, as by 

 this means he gets a far larger and more healthy stock. 



In preparing for seed-sowing, it is necessary to have the soil 

 fine with a good mixture of sharp sand. When the seed is of a 

 rare kind and in small quantity, it is perhaps better to sow in pots 

 in the cold frame ; in this case, when the pot is filled with light 

 soil, it should be firmed down with the bottom of another pot and the 

 surface made smooth. The seed is then laid on the top and covered 

 by a very thin covering of very fine soil. Care should be taken not 

 to sow too thickly, as it is more troublesome to prick the plants off 

 after they are sufficiently grown for that purpose ; no more soil 

 should be laid on the top of the seed than will just cover it, as 

 very small seeds are frequently lost by putting on too thick a 

 After all is finished, the pots should be carefully watered 



