The sky is blue again over the school greenhouse but we have enjoyed a wet couple of days and our rain water tank has gone from very nearly empty to 1/3 full again. Our tank holds 16 000 litres and this month we have been down to our lowest level ever (about 1000 litres). We have been asked what we do if we run out of rain water but so far this has never happened. If we did run out of rain water we would have to use tap water but this would give us limescale deposits on all our leaves as well as reducing the amount we can feed safely in the summer (we can add more feed to rain water than tap water because the total dissolved salts level is so low in rainwater)
The hot spell has been a challenge for some of our cool loving plants as the greenhouse has regularly reached temperatures above 30C. Our policy is not to worry too much but make sure that plants are well watered so that they can cool with transpiration. A few plants have suffered from heat stress like this Masdevallia species which has dropped leaves
Some plants however have loved the extra warmth and our Renanthera imschootiana will be flowering for a second time this summer which has never happened before.