238 GREEN-HOUSE REPCTTINO. \Mardi 



They are all of very easy cultivation, and bloom generally 

 from April to September. (Soil No. 11.) 



Hydrangea hortensis is a well-known plant, and much 

 esteemed for its great profusion of very elegant, though mon- 

 strous flowers. They are naturally of a pink colour, but 

 under certain circumstances of culture they become blue. If 

 grown in brown loam with a little sand, they will preserve 

 their original colour; but if grown in swamp earth with a 

 little mould of decayed leaves, they will become blue.* 

 The swamp earth and vegetable mould being more combined 

 with aluminous salt than brown loam, is the cause of the 

 change : and, when first found out (which was merely by 

 chance), was thought a great wonder. It must have a very 

 plentiful supply of water when in flower, which is produced on 

 the shoots of the previous year. They will neither grow nor 

 flower well if they are not kept constantly in the shade. 

 When kept in the sun, the foliage is very brown; and by 

 being neglected in watering, we have seen the flowers com- 

 pletely scourged. H. japdnica, a new variety with pink 

 flowers, and the same disposition to change colour, a little fra- 

 grant. Being tolerably hardy, when the winters are mild, by 

 a little protection in the open air, they will flower profusely ; 

 the flowers will be very large, and in bloom from June to Oc- 

 tober. They are deciduous, soft-wooded shrubs. 



Ilex, Holly, of I. aquifblium. There are above one hun- 

 dred of them in cultivation in Europe, differing in variegation, 

 margin shape, and size of the leaves: some are onl* prickly 

 on the margin of the foliage, others prickly over all^JK sur- 

 face. In Europe they are all hardy, but with us few or none 

 of the varieties are so. If they become acclimated, they will 

 be a great ornament to our gardens, being all low evergreen 

 shrubs. The most common and conspicuous vai.'eties are the 

 hedge-hog, striped hedge-hog, white hedge, gold, edged', and 

 painted; the flowers are white and small, berries yellow or 

 red ; they do not agree with exposure to the sun. I. Cdssina 

 and I. vomitoria have very bitter leaves, and, though natives 

 of Carolina, we have to give them the protection of a green- 

 house. It is said that at certain seasons of the year the In- 



Mix the iron sparks from the blacksmith's shop with any kind of 

 eoil, and they will be a beautiful blue. One and a half quarts to > 

 bushel will do. 



