Geraniums can be overwintered inside in three different ways: as a houseplant, as a dormant bare root, or as cuttings. Your decision will be influenced by the amount of room you have indoors and the range of temperatures you can tolerate. Here is a closer examination of each method.
Overwintering geraniums as houseplants
If you want to keep the entire potted plant and have lots of room close to a window that gets bright, direct light, go with this option. A drafty west-facing window would be the ideal place for your potted geranium to spend the winter because geraniums prefer it chilly (55 to 65 F is optimum).
Wash the foliage well with your hose and repot the plant in new potting soil to prevent bringing unwanted pests from outside. You might also use insecticidal soap, which is sold in most garden centers and hardware stores as well as online. Avoid taking the plant indoors if it shows any signs of pests or illness. Only strong plants have a chance of successfully overwintering indoors.
During the winter, keep the soil wet but not damp. No more humidity is required. If the stems begin to sag, pinch them back to keep the plant compact throughout the winter. When springtime comes around, you may start fertilizing once more and transfer the plant back outside as soon as the temperature reliably rises above 50 F.
Overwintering geraniums as dormant bare root plants
This is the most typical way to overwinter geraniums, but it won’t work unless you have a dark, dry place that stays around 50 degrees throughout the winter.
First, dig up your geranium before it freezes and shake the dirt off the roots. To stop mold from forming, let the plant sit and dry for a few days before storage. Before moving onto the following phase, the roots must be completely dry.
The roots should be kept in a dark, dry place that doesn’t get colder than 45 degrees throughout the winter. Geranium roots should be kept at a temperature of 50 F. You can keep them by doing:
- It has been customary for generations to hang the plants upside-down from the rafters;
- placing them on a shelf after wrapping them in newspaper or a paper bag;
- they were put in a cardboard box.
Step 3: Every month or so, look for mold, black leaves, or limp stems at the roots. Remove any plant or root components that are harmful. Most of the stems should endure the winter in good shape. Before re-storing them if they become too wilted, give them a good bath in water and let them air dry.
Step 4: Reviving your geraniums involves cleaning them up, pruning the stems back to healthy green growth, and replanting them in new potting soil about six weeks before your final frost date. Where the new roots will grow, bury the stems two nodes deep. When you notice fresh growth in one to two weeks, keep the plants somewhat dry; after that, keep the soil moist until the plants are big enough to replant outside.
Overwintering geraniums as cuttings
If your light windowsill area is limited or you are concerned that bringing in your entire potted plant would also attract unwanted bugs, this is a nice technique to try. Additionally, it’s a fantastic way to multiply your existing geraniums.
To trim plants, you’ll need:
- a cutting edge.
- Rooting hormone, sold online, at most garden centers and hardware stores.
- Use little terracotta or plastic pots, or recycle a clear takeaway container for roasted chicken.
- If you don’t eat chicken, use clear plastic bags to cover the pans.
Will geraniums in containers last the winter?
Geraniums are frequently planted in containers, which is a fantastic option if you want to overwinter them.
In the fall, before the first frost, if your geraniums are already in pots, you can simply relocate the pots under cover into a sunny, airy, and frost-free location, such a greenhouse or conservatory.
According to David Taylor, vice chairman of the UK Pelargonium and Geranium Society, “the best area would be a greenhouse and the ideal climate would be to have a heater in place to preserve temperatures above freezing when frost does threaten.” (new tab opens) (PAGS).
You can dig up, repot, and move the pots under cover if your geraniums were grown in a border.
Geraniums should always be pruned back before being brought indoors, whether they are already potted or have been removed from the border and repotted, according to David Taylor of PAGS.
“First, you should prune your plants back by roughly two-thirds; if lifting from outside beds, they could need to be pruned down by three-quarters or perhaps more. Do this pruning only while the roots are dry; otherwise, the remaining stems will wither.”
‘Also, get rid of any diseased, damaged, or dead sections you see. Make sure they are bug-free before bringing them inside for the winter,’ adds Emily Fernandes, a Californian small-space gardener and HouseGrail expert (opens in new tab).
Geraniums are best kept in a semi-dormant state while enclosed, as this means they won’t need as much water or food. “Place them in a partially sunny area, water them every two to three weeks, and maintain a humidity level of about 50%.” According to Emily Fernandes, a consultant at HouseGrail, “they go dormant over the winter like most other plants to store their energy for the growing season” (opens in new tab).
Can I store my geraniums for the following season?
Geraniums have the advantage of easily entering dormancy, allowing for storage in a manner akin to that of sensitive bulbs. This method of storing geraniums for the winter entails digging the plant up in the fall and carefully removing the soil from the roots. The roots should not be spotless, just clear of dirt clumps.
In a room with a constant temperature of roughly 50 degrees Fahrenheit, such as your garage or basement, hang the plants upside down (10 C.). Rehang the geranium plant after soaking the roots in water for an hour once a month. All of the leaves on the geranium will fall off, but the stems will still be alive. Replant the dormant geraniums in the ground in the spring, and they will come to life.
Does keeping geraniums during the winter make sense?
- Make sure you thoroughly inspect your geranium plants before bringing them inside for the winter. Look for symptoms of pests and illnesses like rust and remove any dead leaves or wilting blossoms. Only zonal pelargoniums are impacted by this, but it is becoming more widespread. It arrived in the nation for the first time in 1968, and it does best in the moist summer or fall months. Fortunately, it doesn’t seem to spread to the plants quickly and is simple to treat, so merely plucking the afflicted leaves is an effective management. You might also consider using the fungicide Dithane 945 as a spray.
- Placing your overwintering plants somewhere bright and sunny will help them retain their need for light throughout the winter. Your plants will receive 50% less light if they are placed more than three feet from a window!
- Because your plants continue to thrive throughout the winter, keep the roots moist. While geraniums frequently survive droughts, they rarely flourish. Show plant growers take special care to keep the roots of their plants damp but never soggy during the winter.
- Ventilate as frequently as you can to maintain a dry environment surrounding your plants. Your plants will turn into a moldy, rotting heap if you don’t allow the air to circulate. The greatest electric fan heaters are those that operate automatically since they circulate air while simultaneously raising air temperature.
- Geraniums are fairly inexpensive to overwinter in the greenhouse because they only need to be kept frost-free. To keep temperatures above freezing, however, we do advise utilizing a heater. Set the thermostat on your heater to 5C, which is 41F. The plant will not survive if the stems become frosty! The winter months are a great time to store your delicate pelargoniums in porches, sunrooms, or conservatories.
We hope that we have provided you with enough of tips so that you can continue to enjoy your geraniums year after year. Visit our geraniums hub page, which is brimming with useful resources, for additional details on how to cultivate and take care of these well-liked plants. And do get in touch with us through our social media outlets to share your personal favorites; we’d love to hear from you.
Can geraniums survive the winter in the UK outside?
Dr. Hessayon has provided practical gardening guidance to millions of gardeners, and his most recent book is jam-packed with fascinating horticultural trivia. This excerpt explains how you can reduce the price of your summer displays the following year.
Geraniums continue to be an essential component of our summer bedding designs. Everywhere you look, you see the striking umbels of red, pink, and white blooms, but any botanist will tell you that the bedding ‘geranium’ is actually the zonal pelargonium, not a geranium at all. Look attentively at the leaves; almost all kinds have a characteristic horseshoe zone or marking.
Geraniums don’t do well in the English winter, so bring them inside to prepare for the next year.
Although less common, the ivy-leaved pelargoniums, which droop over window boxes and hanging baskets, are just as helpful. The perennial shrubby geranium displays that cover hillsides and even balconies in more favored climates will sadly not survive the typical British winter for us.
Bedding geraniums shouldn’t be thrown away at the end of the summer just because they are frost-sensitive; they are far too expensive for that. Dig out the plants and shake off the soil around the roots before the first frosts come. They should be placed in pots that are just large enough to accommodate the roots and filled with seed and cutting compost.
Half the stems’ height should be maintained, and dead flower heads and yellowing leaves should be removed. Place the pots in a cool greenhouse or an unheated spare room. After spending the entire summer outdoors, the plants will be worn down and shouldn’t be handled like indoor plants that need to be encouraged to bloom. On no account should they be kept warm; they need to relax. Don’t feed them, and only water when it’s absolutely necessary to prevent the leaves from wilting.
When spring arrives, place the pots in a bright area and up the watering, but avoid forcing them into active development with feeding and excessive watering. Transplant the geraniums outside as soon as there is no threat of frost so they can develop once again and offer a summer-long display.
By following this protocol, you’ll be able to overwinter your bedding pelargoniums and avoid having to pay for new ones in May or June. This process has several iterations depending on the facilities you have access to. In September, if you have a greenhouse, you can take cuttings from your outdoor plants to dramatically increase the number of plants you have and have a greater show the next season.
However, if you don’t have a greenhouse or a spare room for geranium pots, you might try hanging the old plants throughout the winter in the garage. Before the first frosts, dig up the plants and shake all the soil from the roots. A small group of the plants can be tied together and hung upside down from the garage’s roof. Give them a little dusting of fungicidal powder, such as sulfur, and wait until the spring. Before potting or planting outdoors, soak the roots.
- Adapted from The Bedside Book of the Garden by Dr. D. G. Hessayon, published in 2008 by Expert Books for $12.99. Call 0845 155 0720 to place a copy order (p&p are free).