86 GARDENING DIFFICULTIES SOLVED 



days not opened at all. In winter time the plants would not suffer ; 

 but in spring the young, tender shoots are growing and require 

 plenty of fresh air. But the air must be admitted judiciously in 

 order to prevent cold draughts blowing directly upon the foliage. 

 The top ventilators of a greenhouse should, from March onwards, be 

 opened slightly at 7 o'clock on fine mornings. Then increase the 

 width a few inches at 9 o'clock, and again at 10 o'clock ; and if the 

 outside air be warm and the sun shining brightly, open the front 

 ventilators too at the last named hour. Commence reducing the 

 amount of ventilation at 3 o'clock in the afternoon. The upper venti- 

 lators may be left open a little way each night during the summer. 

 Usually both doors and ventilators may be opened wide in the 

 middle of the day without detriment to the occupants of the house. 

 The danger to avoid is keeping the house closed too long, until the 

 interior becomes very hot, and then suddenly throwing open the 

 ventilators and doors. The opening and closing is best done 

 gradually. 



Marguerite Leaves Ruined by Insect 



Q. Will you tell me what causes those white streaks in Marguer- 

 ites 1 My Cinerarias were also similarly disfigured. I can find no 

 insect. J?. M. C., Bolton. 



A. The leaves received were badly attacked by the leaf mining 

 maggot. Undoubtedly your Cinerarias are afflicted in the same way, 

 for the Cineraria is subject to the attacks of the leaf miner. The 

 larvae are living inside ; they tunnel their way between the tissues 

 of the leaves. By holding the leaves to the light the position, 

 of the larvae may be readily seen. Since the culprits live within the 

 leaves, it is exceedingly difficult to get rid of them. Although many 

 remedies are sometimes recommended, the only certain cure is to 

 remove the worst leaves and immediately burn them, and to kill the 

 other grubs by pressing them between the finger and thumb. If 

 this method is followed out from the first, and good growing con- 

 ditions are also provided, injury from this pest will not be very great. 



Geraniums for Winter Flowering 



Q. Please tell me when I should take cuttings to raise a stock of 

 Geraniums for winter flowering. E. J. K., Maldon. 



A. February is the time to insert cuttings to make strong plants 

 for flowering in the winter in a warm greenhouse. The best cuttings 

 are made from the tops of plants which have flowered in the 



