If you are growing geraniums and thinking about leaving them outside over winter then there will be one question at the forefront of your mind, can geraniums survive frost? Let’s have a look and find out.
Geranium or Pelargonium
This is the main deciding factor in whether your geraniums can survive a frost, are they actually geraniums. Traditional geraniums are frost hardy and can survive frosts without much issue. There is a lot of confusion though as Pelargonium are commonly known as scented geraniums despite being a different plant.
Pelargoniums are from South Africa and are definitely not frost hardy. While they may survive a night or two of light frost they are not made for prolonged cold snaps. They are however from the desert so can survive periods without water. Because of this many gardeners bring them outside and let them go almost dormant over winter before nursing them back to life in spring.
Where in the country are you?
If you are trying to overwinter Pelargoniums by leaving them in the ground then your position in the country will decide whether this is possible or not. If you are up north like me then I would say forget about it, we regularly get temperatures cold enough to kill pelargoniums. You will have to bring them in to a sheltered spot like a greenhouse.
If you are further south or in an area where you tend to have milder winters then you stand a good chance of being able to overwinter them without much issue.
How to overwinter Pelargonium
If you want to keep your “geraniums” over winter inside say a greenhouse or cold frame then there are a few steps you need to take, you cant simply bring them inside and be done with it.
You want to keep them cool and not warm, if they are too warm they may try to flower again which can end up with a tried, weak plant by the time spring rolls around again.
To start with remove the plant from the ground and shake all of the soil off from around the roots so you have a bare root plant. You then want to pot this on into a small pot of poor quality compost, a seed compost is ideal, we are not trying to promote growth here.
You then want to cut the plant back quite a bit to give it less to support over winter. You can remove up to half of the plant without worry. Once that is done you can store it in a cool but importantly frost-free spot.
The pelargonium won’t need much watering over winter, remember they are native to South African deserts, but you can water it whenever the leaves start to badly droop. Once spring rolls round again move the plant into a fresh pot of good compost and move it into a sunny warm spot ready for an explosion of growth.