160 THE BEGINNER'S GARDEN BOOK 



grow bigger and the weather milder, open wider, until by day 

 you can take the sash entirely off. 



At night you must make the best guess you can as to the 

 temperature. Beginning in February, you may be sure that 

 you will need both mats and shutters every night for some 

 weeks. But as the nights grow milder you can first leave the 

 shutters off, except on nights when you feel sure that the 

 wind will blow off the mats if they are not held down. Later, 

 however, will come the time when if there is a wind you may 



be sure that there will be no 

 heavy frost, so that not even mats 

 will be needed, if only the sash are 

 shut. Sash alone will shut out an 

 ordinary light frost, if the plants 

 are not touching the glass. Leaves 

 that touch the glass will be nipped 

 by a late frost, unless the mats 

 are on. 



As the season passes on, and 

 FIG. 83. One way of ventilat- your plants grow with the spring, 



ing the frames. . 



they may grow too last and too 



soft if the hot-bed still remains hot. This is the time when 

 the greenhouseman allows his fires to burn low. Luckily for 

 us, about this time the heat of the manure dies down, so that 

 by the time frosts cease, and the chill is leaving the open 

 ground, our frames are no longer hot-beds, but of their own 

 accord have become cold-frames. 



(And when we take down our frames, by the way, and take 

 up the sub-frame to store for another year, we shall find the 

 manure all ready to use in the garden for plant-food.) 



Cold-frames, if we should now start them, are managed 

 much the same as hot-beds, although through a shorter 

 season. They must be ventilated as the other frames are, 



