Anstveks to Correspondents. Hardy Clematis. — There are near forty species of hardy 

 clematis in European collections, but it is uncertain whether they are so here. The follow- 

 ing list may be relied on ; C. Virginiana, Sieboldii (two varieties, azurea and bicolor), cam- 

 panulata, ccerulea, flamula, florida, florida pleno, Hendersonii, vitalba, Viticella, V. coerulea, 

 V. rubra, V. violacea, V. purpurea, glauca, montana, crispa, smilacoefolia, and viorna. 



Grafting Lemon-Trees. — (A Subscriber, York.) In some countries, grafting is the gene- 

 ral mode, but, with us, budding is most usual. The stocks are seedlings from the lemons 

 of the stores. They are budded when two or three years old — generally in July or August 

 — but at any time when the growth of the stock of scions are half through. It can best 

 be accomplished in a close, moist heat — say in a greenhouse or frame. 



When peach-trees are " frozen," the wood as well as the pith turns of a brown color. 



Peaks on Thorns. — (A Sub., Wilkesbarre.) They unite readily by grafting, but are short- 

 lived, and worthless for all practical purposes. 



Tulip-Trees. — (W. F. B., Ashfield, Mass.) If your tulip-trees are to be taken from the 

 woods, care must be taken to secure as much as possible of the roots ; plant again as soon 

 as you can, and well water at planting. To get them to do well, choose plants five or six 

 feet high, and, after planting, cut to the ground, and select the strongest shoot for the future 

 tree. There will be no time lost by the sacrifice. There is but the one variety. 



Window Plants. — (The same.) Double glazing is highly advantageous in preserving 

 the temperature of rooms in severe weather, and does not materially obstruct the light ; but 

 it is very objectionable, by the condensation of moisture, and growth of green vegetable 

 matter on the inside in such cases. 



Forcing Frames. — (C.) Nothing is more easily forced than lettuce. Indeed, we doubt 

 whether anything is better fitted for the purpose than the common hotbed frame. For 

 artificial heat, stable manure or leaves are preferable. Very little heat is required ; over 

 550 may be considered injurious, unless the plants are very near the glass, which, in any 

 case, they ought to be. If it were desirable to grow them very extensively, no better plan 

 could be adopted than to have long pits constructed with boards or brick, and the whole 

 heated by hot-water pipes carried around on the inside. This could all be done in connec- 

 tion with the small propagating house inquired about — one boiler heating both. For a 

 propagating house, and, indeed, for any kind of greenhouse structure where heat and light 

 in winter is an object, a lean-to house, with a south or southeast aspect, is preferable to any 

 other. In a house expressly for propagating, it is best to have a pit built, so as to contain 

 a few feet deep of tan or leaves, or even sand, with the view of having a slight bottom heat 

 or material to keep moisture around the pots. Sashes are not essential, if you provide 

 sufiicient ventilators in the front and back walls to keep down the temperature when it is 

 likely to rise too high. A house can be built at a considerably less cost, and will cost less 

 to maintain artificial heat, when the roof is built on the house without movable sashes. 

 The entrance should be at one end — at the warmest. 



Where coal and lumber are cheap, houses and frames may be constructed of wood more 

 profitably than of any other substance. 



Dioscorea batatas. — (W. Groom, North Fork, 111.) This stood the winter of 1855-6 hero 

 perfectly. We should say it is "as hardy as a parsnip." They attain a fine size the first 

 year when roots are planted. 



Stuartia Virginica. — (W.) We are pleased that your attention has been drawn to this 

 beautiful shrub. It flowers from July to September, when other bloom is scarce. It thrives 

 best in a peat soil rather moist, but will also grow in deep, moist sand. No fast growing 

 roots should be allowed near it, or they will ovei-power those of the Stuartia. In general, 



