Winter can be hard on house plants because of temperature changes and less natural light.
Rooms that plants live in may go from a few degrees Celsius to more than 20C and back to cold within a 24-hour period as heating is used and turned off.
A room that is continually warm or cold suits plants better than wide temperature changes over short periods of time.
The watering of house plants in winter is a difficult thing to explain because many factors are involved.
Basically, the growing medium (potting mix) should be a little on the dry side most of the time, with only small drinks to maintain this aspect.
If the mix becomes too wet, it will mean the plant will suffer more in the cold times and because the roots are surrounded by water, they lack oxygen and start to rot.
This will appear as stress in the foliage and mistakenly some people will think the pot is too dry and add water, compounding the problem.
Lift a pot plant to judge how much water it is retaining: it is surprising how light they are when bone dry.
If there is water in the saucer beneath the pot, that is a definite sign of overwatering.
If a plant has been in the same pot for a long time, it is likely to be root bound, which means the roots have taken up most of the area in the pot and there is little potting mix left.
A plant in this state will run out of water very quickly and even in winter may need watering every few days.
Once a plant becomes too pot bound, it will die eventually, so there is a need every few years to root prune.
This is done by removing the plant from its pot, sawing off the bottom third of the roots and then placing fresh mix in the bottom of the pot to the height sufficient to cover the area where the roots once were.
Then pop the plant back into the pot. It will need less watering for a while as it fills up the new mix with roots.
The plant will also show a new lease of life.
The mix you choose to use is up to you and a potting mix is better for indoor plants. If the mix has wetting agents in it, they are good for summer but can be deadly for winter if you don't take extra care watering.
Light levels are low in winter because daylight hours are shorter and the sun is at a lower ebb. This can be dangerous for indoor plants, especially those with small leaves.
In the winter, there may be insufficient light for the plant. Moving plants closer to a natural light source (window) will be better for them.
Turning the plant around 180 degrees every week produces more even growth and reduces the reach of the plant for the nearest light source.
A room in which you have heating and which use to dry washing on a clothes horse or similar provides a better environment for plants.
They require less watering, because they get extra moisture though their leaves.
- © Fairfax NZ News