After another good month of harvesting, the end of the season has arrived. Time to rid the plants of their last pods and get them pruned for overwintering.
Overwintering preps & a rocking farewell to the 2013 growing season.
Nighttime temperatures are now coming increasingly close to the margin of 5 degrees Celsius which is about the lowest that most capsicum varieties will tolerate. So I’m now faced with the choice of letting my plants die out on the balcony or giving them a chance to survive indoors.
Since I like to overwinter my fave varieties to keep for myself and to give away to friends I decided to go for the latter, just like I’d done in previous seasons. Unfortunately I cannot supply my plants with the conditions to keep them going indoors, so it’s a good idea to get them prepped up for a hibernation of sorts now.
The measures necessary for that may seem a bit brutal at first glance, but in fact they are helping the plants to survive during the gloomy months of the cold Berlin winter.
After initially removing all of the pods, there’s still a lot of inert mass left to lose on the plants. They have grown a lot of branches and foliage over the course of the season, and they have to constantly keep nourishing and regenerating all these parts.
The plants source the energy they need to do so from photosynthesis, therefore they will only be able to even sustain their current status if they get sufficient amounts of the right kind of light (i.e. 6000 – 7000 Kelvin).
Without a proper grow-room fitted with fluorescent lighttubes (which I don’t have) there’s no way to let indoor pepper plants have enough natural light for supporting all of their foliage during the short and dark days of winter.
So in order for the plants not to wilt and slowly die away until bright springtime arrives, most of their branches and foliage have to go. This is what’s also known as pruning.
I usually start from the bottom of a plant and clip off all of the side-shoots and bigger leaves on the main stem up to its first Y split. Just above the first or second node further up from that Y split I then give a cut to the two branches that have grown from it. Anything that’s already gone woody should stay on the plant, so I make sure to trim only parts of a plant that are still lushly green.
A few leaves left on the plant will help it to support its vital functions throughout the overwintering period. They will also provide some safe signs of when to water the plant once they start to go flabby. In the pictures above and below you can tell the difference before and after pruning.
7Pot Orange-Yellow (c. chinense) fully pruned.
Once the plants have been thoroughly trimmed they are ready to be taken indoors. The most important thing now is to get the balance of light, temperature and water just right.
The small amount of energy that the plants will be able to photosynthesize from the scarce portion of natural light available to them during the Berlin winter will only allow them to support biological activity to a very limited degree. Since higher temperatures stimulate biological activity, putting the plants into a warm place (20+ degrees Celsius) will drive up their demand for energy above the limit that they will still be able to serve.
The plants will try to counteract the energetic imbalance of demand and capability by putting out thin and leggy shoots, searching for more light. Eventually, the stress caused by the imbalance will make the plant deteriorate altogether.
In order to keep biological activity at a level that will allow the plants to survive without stressing them out, temperatures during overwintering should ideally be within the range of 15 to 18 degrees Celsius. This will enable the plants to support their vital functions and cause them to switch into a semi-dormant mode, much like some animals do during hibernation.
I have a spare room with windows facing north to meet these conditions which has turned out to be a fine space for overwintering in the past.
Throughout the entire overwintering phase the plants should be watered very cautiously. With their biological activity slowed down the plants need very little water themselves, so any excess water will stay in the soil and cause the roots to mould. This is why I only pour about 0.2 litres of water into a plant’s pot once the few leaves left on it start looking droopy.
If everything goes well, the plants will spring back to life as soon as both temperatures and the amount of light rise up again around March. Then it’ll be time for re-potting, but that still feels like half an eternity away at the moment.