FLOWERS AND PLANTS. 323 



BIENNIALS AND PERENNIALS. 



Biennials, generally speaking, are sown one summer, and 

 bloom and die the next, as soon as they have ripened their 

 seeds. Most of them are hardy enough to stand our winters, 

 for one summer is not long enough to complete their growth, 

 even with the help of the hothouse, greenhouse, or frame. 

 Many stocks are biennial. The Canterbury bell is a biennial ; 

 and if sown about June, planted out when large enough, will 

 flower about the same time next year. Perennials are plants 

 which do not die at any given period, but would live on, 

 like an oak or vine, if the necessary conditions could be 

 supplied j and the great family of plants comprises most of 

 this kind. 



Hardy Perennials will grow many years on the same spot 

 and spread into large masses. Bulbs increase in number. 

 Fibrous and tuberous rooted subjects spread out into many 

 plants all round, and only want to be separated from the 

 parent. Many of them separate themselves, and when they 

 degenerate it is fi'om remaining too long on the same spot of 

 soil, which they in time exhaust. 



Stove Perennials, cultivated in pots, are from time to time 

 shifted from one sized pot to another, and new soil is filled 

 up all round the old ball of earth, and the plant continues to 

 grow so long as this can be done. Bulbs, such as amarylles, 

 propagate themselves. Corms, such as gloxineas, gesneras, 

 &c., do not multiply much by the roots, but strike freely 

 from cuttings, as wall all fibrous rooted plants. Tuberous 

 rooted subjects, like many of the iris tribe, can be raised 

 from bits of the tuber with shoots to them, but the old plants 

 will live as long as we give them good pot room. The bulbs 

 and corms, when the bloom is over and the seeds are ripe, 

 want rest, and it is only necessary, w^hen the stems or leaves 

 die down, to leave off watering until they start again ; they 

 may then be cleared of the old soil, repotted, and grown on 

 as before. Achimenes, which has become a large family, com- 

 prising many varieties, multiply very fast by their tuberous 

 roots ; and when they have died down and rested about six 

 weeks, the ball of earth may be broken, and the tubers care- 

 fully sorted, — the largest potted again, two, three, or more 

 in a pot, an inch below the surface, and be set to work and 

 watered. To raise the plants of various sorts from cuttings, 



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