IN THE GREENHOUSE

Wairarapa Times-Age, 4 June 1941, Page 8

IN THE GREENHOUSE

WINTER CONDITIONS. Additional precautions must be. taken to keep greenhouse plants healthy during the winter months. The regulation of temperature, ventilation, watering and the maintenance of sufficient moisture in the atmosphere must be attended to daily. Too much heat induces plants to send up weak, sappy shoots. For most plants a minimum night temperature of 45 degrees with a rise of 10 degrees by day is ideal. During very cold nights the temperature may fall to 40 degrees, or every a little lower, without doing any harm. On clear days when the rays of the sun are powerful the heat may rise to 70 degrees at midday. A high temperature of sun heat is beneficial, provided ample ventilation is afforded at the same time, but a similar temperature from fire heat would be detrimental to the plants. As fresh air is essential, the venti- ; lators should be opened on all favour- ■ able occasions. Do not use the side • ventilators except on very mild and windless days. Although the stages and 1 floors must be damped occasionally, care should be taken not to overdo I this or leaves and flowers will be at- I tacked by mildew and seedlings will ■ damp off. n

A continually dry atmosphere is equally harmful, however, as it encourages the breeding of red spider and thrips. Syringing should be done early enough in the afternoon to allow the foliage to become dry by night. Watering, wherever possible, should be done about mid-day in . very cold weather, and puddles which collect on the floor should be mopped up. Cold tap water chills and rots the roots. If a large tank is fixed under the staging, a sufficient supply of water, warmed to the'temperature of the greenhouse can be kept.