How to keep geraniums through the winter

Garden geraniums are tender, so a freeze will kill them, but the plant itself is easy to rescue. Extension services describe three methods, and which one suits you depends on how much window space you have.

Before you bring anything in

Timing matters more than technique. Iowa State University Extension says to dig up plants or take cuttings before the first fall frost,² and Wisconsin Extension says to dig up garden-bed plants or bring container plants in before a hard freeze.¹ Illinois Extension says geraniums must be dug or moved indoors before the first frost.³

Inspect plants first. Illinois Extension recommends checking for pests and disease before moving plants in, and discarding any with leaf or stem spots or discoloration, wilting, rot or insects.³ Wisconsin also advises overwintering only healthy plants and checking for pests before bringing them in.¹

Method 1: keep them as houseplants

This method needs the most space.

1. Dig the plant carefully and set it in a pot with drainage holes that fits its size.³
2. Trim back by one-third to one-half, then water thoroughly.¹³
3. Give it a bright, sunny window or supplemental grow lights.¹³
4. Keep temperatures around 60 to 65°F (Wisconsin) or about 65°F by day and slightly cooler at night (Illinois), away from heat vents and fireplaces.¹³ Iowa State suggests 65 to 70°F during the day.²
5. Water when the soil feels dry to the touch, and pinch back leggy stems just above a leaf node.¹

Illinois Extension warns that warm rooms with too little light make plants leggy.³ If you cannot offer a bright window, choose a different method. In March, Iowa State says to cut plants back by one-half to two-thirds, with regrowth starting within a few days and plants looking good by May.²

Method 2: root cuttings

Cuttings take the least room. All three extension services give nearly the same steps:

• Cut 3 to 4 inch stem tips, pinch off the lower leaves and dip the base in rooting hormone.¹²³
• Insert into a medium such as perlite, vermiculite, peat moss or sand, or a commercial rooting mix, in a container with drainage holes.¹²³
• Keep the medium moist but not soggy, and give bright light but not direct sun.¹²
• Iowa State suggests covering the pot with a clear plastic bag to prevent wilting; Illinois notes it can help hold moisture but to watch for mold.²³
• When rooted, pot each cutting separately. Rooting takes about 6 weeks (Wisconsin), 6 to 8 weeks (Iowa State) or about 4 to 8 weeks (Illinois).¹²³

Once potted, grow them in a sunny window or under artificial light until spring.²

Method 3: store bare-root and dormant

This is the low-effort method, though regrowth can be slow.

• Dig plants before a hard freeze and shake the soil from the roots.¹²
• Hang them upside down, or put one or two plants in a large paper bag left open for airflow.¹²
• Store in a cool, dry place at 45 to 55°F (Wisconsin and Iowa State; Illinois says 45 to 50°F), such as an unheated bedroom, indoor porch, cool basement or garage.¹²³
• Leaves will dry and drop, and shoot tips may die back. Wisconsin and Illinois say this is expected.¹³
• Wisconsin says you can soak the roots in water for a few hours several times over the winter to keep them from drying out completely.¹
• In March, cut back to firm green tissue (Wisconsin says about one-third of the original height), pot up, water thoroughly and put them in a bright spot. Regrowth can be slow.¹²

Method comparison

Back outside

Wisconsin says to keep plants indoors until the threat of frost has passed in spring.¹ Iowa State and Illinois both say bare-root plants can go outdoors in May.²³ If you enjoy bringing summer containers back to life, see how to keep rosemary indoors in winter or care for succulents indoors in winter, and for general winter watering habits see watering houseplants in winter.