Last Updated on October 31, 2021 by Phil
Pelargonium zonale is also called horseshoe pelargonium. It is native to South Africa and belongs to the Geraniaceae family.
As a Pelargonium, it is often mistaken as a geranium, which the genus once was. But, like some other genera, Pelargoniums were separated from Geraniums a while back to form their own genus.
If you look closely at their petals, you’ll notice the difference. While both genera species have 5 petals, all of the geraniums petals are the same size and shape. With Pelargonium, the 2 upper petals are the same while the 3 lower ones are similar to one another. Thus, you have 2 different sets that comprise its 5 petals.
That said, Pelargonium zonale grow up to 3 feet tall. They have succulent-like stems that become more woody as they get older.
They are adorned with beautiful flowers that have single and double flowers carrying varying hues including pink, red and white just to name a few.
Meanwhile, their foliage are somewhat oddly circular shaped with some zones of varying green colors.
Pelargonium Zonale Plant Care
Pelargonium Zonale Light Requirements
Pelargonium zonale thrive when they receive plenty of natural light. As such, they do best in full sun.
But, too much intense direct sunlight can likewise burn their leaves. As such, if you live in a warm region or experience very hot summers, it is a good idea to keep them in bright shade or partial shade during the most intense periods.
Indoors, they are best served in an east facing window since you get lots of sun throughout the day especially in the morning. Plus, the gentle morning sun won’t be intense enough to cause it harm even if the plant received direct exposure.
In the south and west facing windows, you’ll want to monitor how hot it gets in the afternoon. During peak of summers or if you live in a warmer region, direct sunlight may be too much for the plant’s foliage.
Outdoors, bright shade in the afternoon is often the best compromise because during this time its rays can get very intense.
Light is a very big deal for Pelargonium zonale because it needs a lot of it to produces its best blooms. Lack of light will produce fewer and smaller flowers.
Similarly, too much heat can stop blooming. The good news is, once you give them some shade they’ll recover.
Temperature & Humidity
Pelargonium zonale are native to South Africa. As such, they prefer warm weather.
This makes them ideal for USDA Hardiness zones 9 and 11. If you live in these areas, you can keep them outside, in the ground or in containers all year round without fear of climate conditions.
However, below zone 9, you want to watch out for freezing temperatures.
The plant is not frost hardy. And, it is sensitive to colder climates. So, if you bring it outdoors for the summer, it is a good idea to take it inside before frost arrives.
Ideally, keeping your Pelargonium zonale away from temperatures below 55 degrees is ideal. Once things get to this level, its growth will slow down and get stunted.
Allowing it to stay there as the mercury drops will result in stress, then damage and eventually death.
Indoors, you can grow it as a houseplant. Or, just place it somewhere that’s cool and bright.
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How Often to Water Pelargonium Zonale
Pelargonium zonale are drought tolerant plants. This makes them perfect if you live in a dry region. They likewise work well if you’re trying to save water and want to do a rock garden or xeriscaping.
What’s great about this is that it makes the plant low maintenance.
That said, there is a limit. You do not want to let the plant go dry for long periods of time. After a certain period, you’ll notice it begin to decline, foliage turns yellow and drop it leaves. That means it needs water and cannot tolerate dryness past that point.
That said, the best way to keep the plant healthy is to allow the top soil to dry between waterings. This prevents overwatering which is a no-no when it comes to Pelargonium zonale.
Interestingly, allowing the soil to dry then waiting a day or two to let the plant experience some stress before watering seems work best if you want it to produce the most blooms.
When watering, it is best to do so in the morning. This gives the soil enough time to dry from the warm sun. In contrast, nighttime is the worse time to water as the cooler weather will prevent moisture from drying quickly. Thus, potentially leading to fungal problems.
Similarly, don’t water over the plant and get the leaves all wet. This can lead to mildew, mold and other fungus on its foliage.
Soil for Pelargonium Zonale
Pelargonium zonale thrive in rich, moist, well-draining soil.
It can likewise tolerate mildly acidic to mildly alkaline sol (pH between 6.1 to 7.8). But, it does best with slightly acidic soil (pH 6.1 to 6.5).
- In the garden, loamy soil is ideal. Using compost to amend the soil likewise improves its quality, loosens it, and increases the organic matter content.
- In containers, use potting soil instead. Because potting mix is soilless, you’ll need to provide the nutrients yourself via fertilizer or compost. You can use regular potting soil then add perlite, sand or vermiculite to improve drainiage.
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Pelargonium Zonale Fertilizer
Pelargonium zonale does not need a lot of plant food. As such, you won’t need to feed it if you have rich soil.
If you don’t have ideal soil, you can add compost to improve its quality and organic matter content. Amending it will mean less need or eliminating fertilizer all together. And, all you’ll need to do is add a layer of compost around the plant each spring.
That said, if your garden has poor soil or you’re growing the plant in a container, you’ll need to use fertilizer.
Here, apply water-soluble fertilizer every 2 to 4 weeks during its growing season. You don’t need to feed it during the fall and winter.
Pelargonium zonale does not need a lot of pruning.
However, you will want to remove the spend flowers. These will bloom from April to October. After that, they will fade. Cutting them back will allow them the come back in the next growing season.
In addition to deadheading, trim any leggy stems, yellow or brown foliage as well.
The plant grows up to about 3 feet tall. This may or may not be too big depending on where it is grown.
In the garden, its height will be much shorter than most other plants. But, in a container indoors, this can be sizable depending on where you decide to put the pot.
As such, you may need to prune it to limit is size and shape as well.
Pelargonium Zonale Propagation
Pelargonium zonale are best propagated from stem cuttings. The best time to propagate it is during spring and early summer.
You can likewise take advantage of doing so when pruning as you’ll be taking cuttings then anyways.
Here’s how to propagate Pelargonium zonale from stem cuttings.
- Take softwood or herbaceous cuttings. Use a sterilized pair of shears or scissors.
- Ideally, pick a healthy, non-flowering stem that’s between 4 to 6 inches long. Make sure it has at least 3 or 4 leaves.
- Remove the lowest leaves since they’ll end up under the soil.
- Fill a small container with potting mix. You can use a combination of peat and sand for the mix.
- Water the potting soil until moist. Don’t overwater.
- Plant the stem cuttings into the soil. You can plant one or multiple cuttings into the pot. If you decide on the latter, you may want to use a larger container depending on how many cuttings you want to grow. Make sure there’s enough space between them.
- Cover the pot with a plastic bag.
- In about 2 to 4 weeks, the cuttings will have started to develop roots.
- Prepare separate containers and move each of the cuttings to their own individual container filled with potting mix.
How to Repot Pelargonium Zonale
If you grow your Pelargonium zonale in containers, repotting will be needed once in a while. The plant is not an overly large plant. But, it will grow up to as high as 3 or so feet.
That said, it does like being slightly pot bound. So, keeping it in a slightly small container works well.
This also means that you can leave it in its existing pot for a little while longer than other plants before moving it.
Wait until the plant’s roots start coming out of the drainage holes at the bottom of the pot. This is a sign that it has outgrown its current home and is looking for more soil beyond it.
When it comes to repotting, there are a few things to remember:
- The best time to do so is during spring to early summer
- Make sure that container has drainage holes.
- Use well-draining soil. This in combination with the drainage holes will prevent overwatering.
- The plant will experience shock after repotting. So, give it some time after to recover. It will then start growing again after it overcomes the shock.
Finally, do note that because the volume of soil is limited you will need to water it and feed it more regular than in the garden.
Pelargonium zonale are toxic to both humans and animals. As such, keep it away from the prying hands and mouths of young children, dogs and cats.
If ingested, it can cause vomiting, loss of appetite and irritation.
Aphids, whiteflies, spidermites and thrips are among the most common pests that will threaten your Pelargonium zonale. These are all treatable with insecticidal soap then rinsed with water.
When you do spot any of these critters, make sure to quickly isolate the affected plant so as not to allow the pests to travel to other nearby plants. They tend to do so. And, this will increase the amount of work you need to do to eradicate them.
Every now and then, you may likewise experience vine weevils and caterpillars.
Diseases are actually more problematic for your Pelargonium zonale because it stays in warm, humid conditions. Thus, if there’s a lot of moisture in the air, you want to make sure to keep the plants dry.
It is susceptible to leaf spot, gray mold and other fungal issues.
As such, good air circulation is crucial as it helps any excess moisture dry faster. This will prevent it from staying too long on foliage.
Speaking of which, you also want to do your part. That is, don’t water over the plant and get all the leaves wet. Similarly, splashing water all over the place with a hose when you water will get leaves wet.
If this does not dry fast enough, it can end up increasing the risk of these fungal infections.
Finally, don’t overwater. Too much water or allowing the plant’s roots to sit in water can cause root rot.