Overwintering Geraniums

Geraniums (pelargoniums) are a popular garden plant typically grown as an annual. In reality, this plant is a tender shrub that can easily be saved from year to year. While these plants can be overwintered in the containers they were planted in, for some gardeners, space and temperature can be an issue. Fortunately, geraniums can be overwintered without soil and in less than ideal conditions. It’s easy and inexpensive.

Preparing and Storing Geraniums for Winter

Most homes no longer have root cellars or unfinished basements. This can create space and temperature problems for overwintering large numbers of potted plants. In some areas of the United States, it’s possible to store geraniums in containers in a garage. However, for gardeners living in areas where winter temperatures sink below zero, garages are typically too cold. Fortunately, geraniums are hardy and most can be stored over the winter without soil. One exception is the Regal varieties, such as Martha Washington, which have different winter care needs.

In the fall, before first frost, dig up geraniums and shake soil from the roots. Remove any dead leaves and spent blooms. If a plant is diseased or severely insect infested, toss it. Place plants in either a brown paper bag or a cardboard box with a lid. Checking plants monthly while in storage and misting any plants that are shriveling will increase the success rate of re-growth in the spring. However, even if plants are left alone it’s reasonable to expect a 70-80% success rate.

Geraniums like to be stored in a dark, cool place. Ideally, storage temperature should be about 50 degrees. This can be difficult to find in homes with finished basements. Aim to find the coolest place in the home. This could be a storage room, under stairs, or even a closet. An ideal place is a room closed off to preserve heat in the rest of the house.

Potting Saved Geraniums for Spring Planting

Bring geraniums out of dormancy in late March or early April. Start by inspecting plants. Discard those that are shriveled or rotting. There may be new growth starting on some plants that is white or pale green. The pale color is a reaction to the dark but is a sign that the plant is viable. A couple weeks in the sun will return it to its healthy green state.

Cut plants back by about two-thirds. Make sure to preserve any new shoots. Remove dead leaves. Plant in containers with good quality potting soil. Include a time release fertilizer in the soil or use half-strength liquid fertilizer. Water thoroughly but avoid overwatering. Place near a sunny window but avoid direct sunlight or extreme heat until plants are fully out of dormancy.

Geraniums are such a popular garden plant, it really is a waste to throw them out every year. Even without extra space or ideal conditions, it’s still easy and economical to save geraniums over the winter months for use year after year.