I hope you have had a wonderful display from all your Pelargoniums this summer?
As the days begin to draw in it is time to begin to think about putting the garden to bed for the winter and that includes your Pelargoniums. They are not frost hardy so will not survive our winters. Ideally they would like you to pack them up and send them off to the Med for the winter months.
However if Mediterranean residency is not a possibility then I can give you some good advice on how to overwinter your Pelargoniums here in England.
So, the most important point is that wherever you choose to keep your plants for the winter is that it is frost free and dry. So a cold greenhouse will not do, nor will a shed if we get a cold winter. Neither will stay frost free for long.
If you have a heated greenhouse or a conservatory that will be heated through the winter, these are ideal places for your Pelargoniums to be overwintered as green plants. Many will continue to flower well into the winter for you if they get enough winter sunshine and food.
If neither of these are an option for you then a garage attached to the house (to benefit from some of your residual central heating warmth) or a spare room will do nicely.
For this option you must prepare your plants for the winter. They need to be allowed to dry out in their pots and then with clean sharp secateurs cut them back hard.
Now, this is where you will need to be mentally strong, you will feel awful, after all summer feeding and watering your plants, I am now asking you to cut them right back.
Cut them back to about 3inches and then take off any leaves that are left, you should be left with just stumps.
They will look dreadful but by removing the aerial part of the plant you are removing the need to water them and all that material that would offer perfect conditions for botrytis (grey mould) to grow during the winter months.
These ‘stumps’ now need to be kept frost free and dry for the winter, so no watering, not even a little bit! You are putting them into hibernation for the winter. They do not need light so a garage will work or a spare room. The most important point is to keep them dry and frost free from here on.
Do not cover them in plastic to give them extra frost protection they will just sweat in there and the dampness will encourage grey mould which will just kill them off.
Fleece can be used to offer a little extra protection but it would be good to make sure it is removed occasionally to allow fresh air round your plants to ward off any possibilities of grey mould.
Now here is the tricky part:
You have to leave them alone till the end of the winter, no well meaning watering after New Year when we all get that ‘January itch’ to start doing things in/for our gardens. A well meaning watering at this point will just lead to a soggy mess of grey mould for you to find at the end of winter, leave well alone!
Now this is not a failsafe system, sometimes for reasons unknown plants do not survive but if you can get say 50% through the winter then it is well worth a go.
For a video with step by step instructions showing you how hard to cut your plants back find the You Tube channel “GeraniumTv” and look for the video “How to cut back Pelargoniums (Geraniums)”.