Are Geraniums Frost Hardy

According to the University of Florida, one of my favorite container plants, geraniums, cannot withstand a cold. However, if they have had some time to acclimate to the chilly weather, they may endure a light frost.

Geraniums can withstand a frost.

Knowing how to overwinter geraniums is very useful for gardeners since it can help them save money and extend the life of particular varieties they enjoy.

Pelargoniums, sometimes known as geraniums, are mainstays of the summer garden. Geraniums are ideal for adding cheer and long-lasting color to hanging baskets, containers, and borders since they come in a variety of colors and flower continually as long as they are deadheaded.

However, when making your job list, you might consider including them as one of your winter garden ideas.

When growing frost-sensitive plants, planning a winter garden is crucial. Geraniums are perennial plants that put on a long display, but they are frost tender, which means they won’t survive harsh winters. If you are interested in cultivating geraniums, you must learn how to overwinter them.

Geraniums are South African natives that thrive in the heat and can withstand periods of drought with little water.

Pelargoniums, sometimes known as geraniums, may live in USDA zones 7 to temperatures of -12oF (0oC) if they are sheltered. They are hardy in climates between 20oF and 50oF in zones 9 through 12. They need to be sheltered in these conditions because, while they can withstand brief frosts (temperatures slightly below freezing), they cannot withstand prolonged exposure.

The Pelargonium genus contains a wide range of cultivars, all of which are categorized as delicate perennials. According to David Taylor, vice chairman of the UK Pelargonium and Geranium Society, “this means that they are not cold hardy as the majority of the founding species come from the warmer climbs of the Southern Hemisphere.

Perennial plants are able to flourish for a number of years, however in the UK this would mean that they would also need to be sheltered from winter wet and damp in addition to frost.

Geraniums can be cared for like annuals by being dug out in the fall, composted, and then replaced with fresh plants the following year. The appropriate care and attention, however, will enable you to winterize geraniums, keeping them alive throughout the winter so they can bloom once more the following year.

According to David Taylor, vice chairman of the UK Pelargonium and Geranium Society, “Keen enthusiasts keep their pelargoniums in growth during the winter and continue to feed and water but a few key points can be undertaken by anyone to keep your pelargoniums (geraniums) alive throughout the winter” (opens in new tab).

Pelargoniums are known as geraniums, but these plants are not the same as hardy geraniums or cranesbill, which are a different kind of plant and don’t need to be overwintered.

What is the geranium’s optimum temperature range?

Gardeners have traditionally favored geraniums. They smell wonderful, are colorful, and are simple to grow. How to cultivate geraniums in your house and garden is provided here!

(Note: This page is about Pelargonium plants, sometimes known as geraniums or storksbills. This is not a page about “hardy geraniums, also referred to as cranesbills.

Geraniums are normally kept indoors to overwinter, even if they may be kept outside throughout the warmer months of the year. In contrast, if given enough light, they can bloom all year long indoors.

Geranium or Pelargonium? A Case of Mistaken Identity

Early in the 18th century, Dutch traders who were traveling through South Africa brought the plants that we now refer to as “geraniums” to Europe. Botanists misclassified these new plants into the same genus because they resembled the hardy wild geraniums that are already present throughout Europe.

Botanist Carl Linnaeus of Sweden included them in the genus Geranium in 1753. Pelargonium, which refers to the long, sharply pointed shape of their seedpod, was used to reclassify these new “geraniums when it was later revealed that they differed from European geraniums in the shape of their petals, the number of stamens, and other features.

However, people still refer to them by their old common name, “geranium,” even if we really mean “pelargonium.”

You can grow geraniums as annual blooms or as indoor plants. They can be kept outside in a sunny area throughout the warmer months of the year (between your local frost dates).
If keeping geraniums as indoor plants, make sure to do so in the late summer or early fall when overnight lows begin to consistently fall below 55F. (13C).
Pay great attention to the size and color of geraniums when purchasing them. Healthy stems and leaves will not be straggly or discolored on top of them or underneath them. A plant with evident insect indications should also be avoided. Mealybugs, whiteflies, and spider mites are typical indoor plant pests.
To prevent root rot, put plants in containers with drainage holes.
When planting in pots, use a well-draining potting mixture rather than heavy, clayey soil. Geraniums dislike being planted in mucky, compacted soil.
Place the plants where they will receive 4-6 hours of sunlight per day for the best bloom.

How to Care for Geraniums

After letting the soil somewhat dry between waterings, water it again well.
Water plants significantly less throughout the winter, but make sure the roots are not completely dried up. Given a time of hibernation throughout the winter, when they consume less water and don’t grow as much, geraniums thrive. For additional overwintering tips, see the section below.
Regularly deadhead spent flowers to promote blooming.
Pinch back the stems to encourage bushiness and prevent legginess.
Fertilize approximately every two weeks throughout the active growing months. Half-strength a fertilizer that is water soluble When the plant should be dormant in the winter, avoid fertilizing.
Repotting geraniums can be done in the spring to promote new growth or if they appear to need revitalization.

Overwintering Geraniums

If they receive plenty of sunlight, geraniums that have spent the summer outdoors can be kept indoors. The sun may not be strong enough in northern regions in late winter to promote buds on some cultivars.
Lift the plants before the first fall frost (you can find your local frost dates here), and use a sharp, clean knife to shapely prune the stems back to about 6 to 8 inches. In the low-sunlight environment they are about to enter, they shouldn’t have to maintain substantial amounts of leaves. A simple technique to increase the number of your plants is to save a few stems for rooting.
Place the “mother plant” in the smallest pot you can find—just big enough to hold the roots—and fill it with ordinary potting soil.
The plants should be kept in the shadow for a week before being moved to a sunny location and kept cool.
Geraniums thrive in temperatures between 50 and 60 degrees Fahrenheit (10 and 16 degrees Celsius) at night during the winter, but they can also withstand lows of 32 degrees Fahrenheit (0 degrees Celsius) and highs of 80 degrees Fahrenheit (27 degrees Celsius), provided they are kept relatively dry.
Cut off all the old leaves when the spring growth begins.

Keeping the new growth alive is the only challenge that can compare to getting it to appear. Here is some assistance with that:

Only offer tiny quantities of water when the leaves begin to droop. Don’t feed or fertilize the plants. These plants must have some downtime.
Pinch back your overwintered geraniums in February if you want them to bloom by Memorial Day. Take the plants outside and move them to beds or pots, as you like, once warm weather returns and all threat of frost has passed.
Containers are ideal for growing the Common or Zonal Geraniums (Pelargonium x hortorum) (as well as outdoors).
Hanging baskets, window boxes, and containers are all extremely popular places to use Ivy-Leaf Geraniums (Pelargonium peltatum).

How to Root Stem Cuttings

The majority of geraniums readily take root from stem cuttings when placed in soil, sand, water, perlite, or another rooting medium.

Make a slanted incision 4 inches below the tip of the stem, above the node where the leaves emerge, with a clean, sharp knife. Cut the grass immediately below a node. Remove all except two or three leaves, any buds, and the stipules that resemble leaves at the base of leaf stalks.
To ensure that the cut end of the stem will seal and not rot, roll the stem cutting in newspaper or place it in the shade for 24 hours.
Place the stem in a wet rooting media container and keep it there for two days in a warm, shaded area. Give the cutting indirect sun after that. Just as needed, moisten the medium.
Apply crushed geranium leaves to small cuts to halt the bleeding.
Scarlet geranium is the flower that speaks of foolishness. More floral meanings can be found here.
You won’t have to worry about those bothersome bugs because geraniums are known to be harmful to Japanese beetles.
Keep geraniums out of the reach of curious youngsters and animals (cats, dogs) as they might cause indigestion or vomiting.

Low light, overexposure, and underwatering are common issues. Yellowing leaves are a sign that you are watering your plants either too little or too much. Try to water the geraniums evenly in this situation, and transfer them to a more sunny location.

What degree of indoor temperature is appropriate for geraniums?

Geraniums do best in climates between 65 and 70 degrees Fahrenheit during the day and 55 degrees Fahrenheit at night. Horticulturists at the University of California claim that scented geraniums only require four hours of sunlight each day. Install a fluorescent light a few inches above the plants if you are unable to provide them with this. When you bring your potted plants inside after it gets below 45 degrees Fahrenheit, the sudden warmth may shock them, turning their leaves yellow and making them fall. Bring the plant indoors for a while before it becomes cold outside, ideally at night, to prevent this. Each day, gradually lengthen the time. This will ease the plant’s transition and minimize major stress. Give the plant more care and ensure that it receives the right amount of water, light exposure, and trimming until it recovers if it still exhibits indications of shock.

Should I protect my geraniums from frost?

According to the University of California, outdoor geraniums should be kept frequently watered, especially if they are in pots, to help protect them from an unusual cold snap. In comparison to dry ground, which will instead rob moisture from the roots, weakening the plant, moist soil that freezes causes less damage to plant roots.

To shield geraniums from the cold before light frosts, cover them with “tents fashioned from newspaper, cardboard, a bed sheet, or burlap. Avoid letting the cover touch the plant itself because this will allow the geranium to become frosted. Place mobile geranium containers in safe settings, like next to house walls, which are typically several degrees warmer.

Can you leave geraniums outside in the winter?

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 I plant geraniums outside yet?

If you don’t have an indoor room, cover the tray with horticultural fleece and leave it in a protected area of the garden. When your geraniums first arrive, place the tray in a frost-free, light, draught-free environment. Water gently by misting or by standing in a shallow tray of water.

Give the plants 24 hours to relax. If the leaves appear a little yellow or if some compost has separated from the root blocks, don’t be concerned.

Large-sized geraniums can be planted right away as long as the risk of frost has gone, while medium-sized geraniums should be nurtured on for 24 weeks before planting.

Be sure to water your plants well.
Push the individual cells up from bottom and out of the tray with your finger or a pencil. Grasp one of the leaves and carefully pull yourself up. Avoid attempting to grip the stem since doing so will seriously harm the plant.
Create a tiny hole in each 9 cm pot of compost and fill it with the cell (one plant per pot). Make sure the joint where the stem and leaves meet is above the surface of the earth, then gently press the plant into the ground.
After transplanting, give the plant a gentle watering and place it somewhere warm and out of direct sunshine.
After a week, feed with a liquid feed and maintain well-hydrated.
They should be prepared for planting after 24 weeks if you maintain the complete stem exposed and the plug submerged so the top of the plug is level with the soil surface. You can plant them in beds, borders, hanging baskets, or planters. After planting, liberally water the area.
After planting, if there is even a little chance of frost, cover with fleece for the night to prevent the leaves from turning brown.