The first factor to keep in mind when overwintering geraniums is whether your variety of geraniums are worth the trouble or if it’s best to let them be and purchase another more agreeable variety the following year. Additionally, make sure that you have enough space for your plants. A greenhouse is the ideal solution if your geraniums have grown quite a bit when freezing temperatures come around.
Light freeze, kills tender plants: -2℃ to 0℃.
Moderate freeze, kills most vegetation: -4℃ to -2℃.
Severe freeze, heavily damages most plants: -4℃ and below.
Otherwise, you can leave your plants as they are and place them into pots, root new cuttings, or cut back your plants for them to regrow and bush out. There are three main methods for overwintering geraniums:
1. Propagate geranium cuttings to create new plants.
2. Overwinter geraniums inside or in greenhouses.
3. Store geraniums’ bare roots.
Moving Plants Indoors
Providing that there is enough sunlight, you can move your plants indoors or keep them in a greenhouse. This will help to make it easier for the geraniums to stay alive until spring. Just prune your plants to between approximately half to a third of their original height and dig them up carefully.
Place the geraniums in a 6-8-inch pots, ensuring that the plants are thoroughly watered before you place them in a bright and sunny area. Artificial light also works brilliantly. Geraniums prefer temperatures around 18℃ during the day and temperatures around 13℃ at night.
Should you notice your geraniums becoming spindly and tall, then you need to make sure that the room they’re in isn’t warm and poorly lit. They only need to be watered when the soil becomes dry, so be careful not to overwater and drown your plants.
Store Bare Root Plants
This very popular method almost always guarantees results. Dig up your plants and shake off the soil carefully. Afterwards, hang them upside down somewhere cool and dry, around 7℃ to 10℃. You can also place each plant in a large paper bag, which is a much cleaner way of storing the geraniums.
Make sure to soak the roots once a month, leaving them in water between one to two hours. The majority of the plant leaves will fall off eventually, so make sure to cut back or prune your geraniums in spring. Make sure to remove all dead material and water them thoroughly.
Taking cuttings to overwinter geraniums is useful when you have a lot of plants to overwinter, especially for soft-stemmed pelargoniums that can’t be overwintered in a dormant state. You can follow our handy guide to know how to take geranium cuttings - which is extremely easy and they root very quickly, too.
Geraniums flower easily all that time with little effort - it’s no wonder they’re so popular! They also tend to be very forgiving when it comes to weather conditions. Although they’re considered perennials, they are often treated as annuals in areas with cold winters, where they are kept indoors or in greenhouses. If you have any questions about how to overwinter geraniums or about any of our products, make sure to contact us on 0845 602 3774 - our friendly team is always happy to help.