Since September, along with the reduction of daylight hours, I start to gradually reduce the watering of cactus and prepare them for overwintering. While it is still warm outside, I carefully inspect the plants for pests or diseases.
Usually, if hygiene rules are carefully followed on the window sill during the summer, the autumn inspection does not reveal any problems. But if an unpleasant find has occurred, now is the time to conduct a course of treatment and thoroughly clean the window, window sill, and frame to ensure that the plants are safe until spring.
Why do cactus need a dry overwinter?
This is what collectors call the rest period. Like every other plant, they need it to gain strength and prepare for the next flowering. Just because there is no overwintering period, many cactuses refuse to bloom for years.
To put a cactus into hibernation, you need three conditions:
- Lack of watering
- Light limitation
- Temperature decrease
From November to March almost all types of cacti do not require water. In the natural environment, they hibernate during drought – lack of rain stops growth, cacti go into rest mode.
In our climate, dark winter months are optimal periods for rest, especially since we can not change this seasonal feature. If we continue watering with a lack of light, the cactuses begin to stretch and lose shape, the new thorns grow weak and unsightly.
It happens that the lack of light and moisture is not enough to begin overwintering. If you see that the cactuses continue to grow stubbornly, measure the temperature on the window sill: heat can severely disrupt your plans. The optimal temperature for overwintering for most guests from the desert is about 13-15 ° C, but the optimum temperature that we can bare which is about 22-26 ° C, is unfortunately not suitable for their resting period. That is why collectors allocate a separate room for the plants.
We control the cactus temperature
If the temperature on the window sill is a little higher than necessary, you can keep a foil-glued cardboard or similar material – the room will remain warm, but it will not reach the window sill, because it will be reflected by the foil to the centre of the room.
A more radical way is to fix the greenhouse film on the window opening in such a way that it forms a partition between the window sill and the room up to the height of the ventilator. This will reduce the level of light in the room, but will also serve as thermal insulation. When airing in sunny weather cold air will sink to the window sill. Cactuses are good, and people do not freeze!