Iowa’s AMES Beautiful plants like geraniums offer color and life to any landscape. They are not prepared to endure the hard winter weather, though. Geraniums can be brought indoors to overwinter and then replanted in the spring.
Horticulturists at ISU Extension and Outreach can assist with your inquiries regarding overwintering geraniums and how to keep them healthy during winter weather.
How can I overwinter geraniums indoors?
By obtaining cuttings, potting up individual plants, or preserving bare-root plants in a cool, dry place, geraniums can be overwintered indoors. Before the first fall frost, remove plants from the garden (or take cuttings).
How do you take geranium cuttings?
Take three- to four-inch stem cuttings from the terminal ends of the shoots using a sharp knife. Pinch the bottom leaves off each cutting before dipping the base in a rooting hormone. Insert the cuttings into vermiculite or a mix of perlite and sphagnum peat moss as a rooting media. Rooting containers that have drainage holes on the bottom are pots and flats. Just enough to allow the cuttings to support themselves should be inserted into the media. Water the rooting media once all of the cuttings have been placed.
Place a clear plastic bag or dome over the cuttings to stop the plant foliage from wilting after allowing the medium to drain for a few minutes. The cuttings should then be placed under bright light—not direct sunshine. In six to eight weeks, the cuttings should begin to root. Remove the cuttings from the rooting media after they have healthy root systems and plant each rooted cutting in a separate pot. Until spring, keep the potted plants in a window with natural light or under artificial lighting.
How do you overwinter geraniums as potted plants?
Each plant should be dug up carefully and put in a big pot. After giving each plant plenty of water, set the geraniums in a window with natural or artificial light. Geraniums prefer a cool environment indoors. The ideal temperature range is between 60 and 65 degrees Fahrenheit during the day and a little bit lower at night. Plants need watering around every two weeks. By the end of winter, geraniums are likely to grow tall and lanky. Trim the plants back in March. Reduce the geraniums by a third to a half. Within a few days, the geraniums will start to grow once more, and by May, they should be beautiful specimens.
How do you overwinter geraniums as bare-root plants?
The geraniums should be carefully dug out before the first fall frost. Remove the plant’s roots’ soil by shaking them. After that, put one or two plants in a sizable paper bag and keep it dry and cool (45 to 50 degrees Fahrenheit). It might be appropriate to use an indoor porch or an unheated bedroom. Hanging the plants upside-down in a cool, dry area is a another (somewhat messier) option. Eventually, the leaves and the shoot tips will wither away.
Trim or prune each plant in March. Get rid of all the dried-out, lifeless stuff. Return to firm, green, living stem tissue through pruning. After pruning, pot the plants and give them plenty of water. Put the potted geraniums in a window with natural light or next to a light source. March pruning and potting of geraniums should result in lovely plants that may be put outside in May.
How do you rouse sleeping geraniums?
Dormant, full-size geranium plants can be overwintered in the same way as animals hibernate during the winter and then come out of it in the spring.
Steps to Overwintering Dormant Geraniums
- Before the first frost, transplant the geraniums into containers and prune the plant back by about half. Dehydrate the soil in the pot.
- Put a paper bag on top of each plant and turn it over.
- Containers for dormant plants should be kept in a garage or basement that is chilly, unheated, and slightly damp.
- Every few weeks, check the geraniums to make sure the stems and leaves are not shriveling. Spray them with water or mist the roots if they start to show signs of drying out. After that, let the plant thoroughly dry before putting it back in the paper bag.
Reviving Dormant Geraniums
- Relocate your dormant geraniums to indirect light around 6–8 weeks before the final anticipated frost.
- Trim any dead leaves from the plants, and cut stems back to a healthy, green growth.
- Give the potted plants a good soaking and some fertilizer that has been diluted.
What should you do with geraniums that overwintered?
Geraniums are incredibly simple to store for the winter—just place them in a cardboard box or a paper bag and secure the top. The following advice will help them survive:
- Maintain geraniums in a cool, dry area with a temperature of 50 to 60 degrees F.
- Once a month or so, remove dried leaves from the bag or box and check for mold.
- Check the stems quickly at the same time; they should be firm. Throw away any dried-out, shriveled stems you uncover.
- If you see that the plants are becoming really dry and crispy, give them a brief soak in water.
- Plants with stems that appear to be blackened or mildewed should be disposed of.
Geraniums are typically kept in a sack upside down. Although the exact cause is unknown, one idea holds that it does so by pushing moisture into the stems. Whatever the cause, storing them in this manner is neither harmful nor necessarily harmful.
Bring Inside as Houseplants
You can bring your potted geraniums (Pelargoniums) indoors for the winter if you have space for them in a sunny place.
While they require sunlight, they thrive in temperatures between 55 and 65 °F (12-18C). I have tremendous luck keeping the air around them a touch colder than the rest of the home with a west-facing window that is slightly drafty.
Dig Up and Repot if Desired
To make sure they are content, healthy, and bug-free, some preparation is needed.
- Before the first frost, dig up and container your geraniums if they are in the ground.
- If they are already in pots, you can repot them if you want, but first perform a rigorous pruning and a bug inspection (see below).
- Trim any extremely long roots or any unkempt root balls before potting.
- Put flowering plants in containers using potting soil made for them.
Hard Prune
- Cutting back the entire plant by between one-third and half is an usual recommendation.
- Any dead, broken, moldy, sick, or diseased pieces should also be taken out.
- If the plant is otherwise good and healthy, you can try keeping any buds or blossoms even though this harsh pruning is ultimately ideal.
Are geraniums able to survive the winter in the ground?
- 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.
How can I grow geraniums from last year again?
Many gardeners grow geraniums (Pelargonium spp.) as perennials in frost-free locations like U.S. Department of Agriculture plant hardiness zones 10 through 11, where they are kept from one year to the next. These plants, like other perennial shrubs, can survive the winter with just a trim and some mulch. You can only preserve your geranium for another year if you bring it inside for the winter if you live in a cooler climate.
Prior to the first freeze in the early winter, dig up your geraniums with a shovel. Step on the shovel’s blade after inserting it on the exterior of the geranium root area to force it down. To remove the geranium roots from the earth, pull back the shovel handle. Shake the soil from the roots of the plant by lifting it by its stalks.
Put the geranium stems, roots up and foliage down, in a cardboard box. Place the box in a dry space in your home or garage that is between 50 and 60 degrees Fahrenheit in temperature. Throw away any dead leaves and withered stems, and use scissors to cut off any mold that develops on the plants.
Stems that appear dry should be submerged in water for two minutes. Replace in the exact same spot in the box after patting dry with paper towels. Up until six weeks before to the last frost, keep the geranium stems in their current location.
Fill a planting pot with soil-free potting mix that has enough drainage holes. Each geranium stem should have the top cut off, leaving just strong, green growth. The lowest two leaf nodes must be pressed into the medium until they are covered by the dirt. Put 1 inch of water on the plant. Only apply more water if the soil is dry about an inch below the surface. In two weeks, look for new growth. The geranium is prepared for outdoor replanting one month later.
In a bed with well-drained soil and at least six hours of direct sunlight, plant the geraniums. Put them in place at the same depth as in the pots. Weekly 1 inch waterings with 10-10-10 liquid fertilizer mixed in according to half the label’s instructions. In most cases, 100 square feet of flower beds require 3.35 ounces of liquid fertilizer to be diluted in 20 gallons of water.
Do geraniums grow back after the winter?
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.