Geranium care is central to having the best flowering and most vigorous geranium plants. Like all plants, geraniums (Pelargonium xhortorum) have their share of growing problems. These problems range from seedlings damping off to tall and spindly-looking plants and everything in between.
Luckily, we as gardeners cause most of these problems and therefore, can easily fix them. We just need to know the best practices involved when growing and caring for geraniums. This especially important if you are growing geraniums in pots.
In this post, I’ll share the best geranium care tips including how to troubleshoot common problems as well as provide actionable fixes.
Armed with this information on proper soil selection, planting, location, and care tips, you’ll keep these popular annual plants healthy and blooming all season long.
The Best Geranium Types to Grow in Pots
If you’re looking for the best geranium types to grow in containers, go for those with compact growth. They will give you the best chance to succeed. Good examples are named series such as 'Elite' geranium and 'Orbit' geranium.
Another great alternative is Pelargonium citronellum 'Mabel Gray' which you can grow for foliage instead of their flowers. Their foliage is highly fragrant and smells like mint, rose, lemon, cinnamon, or even chocolate.
Other common geranium types are:
- Zonal geraniums or Common Geraniums (Pelargonium x hortorum) – They usually have distinct leaf markings. They include selections with tri-colored leaves, silver leaves, leaves with white markings, and fancy-leafed geraniums. Flower colors are usually pink, red, or white.
- Ivy-leafed Geraniums (Pelargonium peltatum) - They have a trailing habit and their leaves resemble ivy plant leaves. They are commonly used in hanging baskets and window boxes.
- Martha Washington Geraniums (Pelargonium x domesticum) – They are available from many florists during the winter months as flowering pot plants. Like ‘Mabel Gray,’ they are not heat-tolerant and will not perform as well outdoors as the common geranium.
How to Grow and Care for Geranium in Pots
Starting the seeds vs planting geranium cuttings
Over the past years, most geranium varieties were grown vegetatively from cuttings. Today, many varieties are available from seed giving gardeners options to choose from. You can start seedlings indoors before transplanting them into containers.
However, the biggest challenge is seedling damping-off which is prevalent during germination.
To control this, you should clean the containers used for starting seeds and make sure they have adequate drainage. If you’re re-using containers make sure you wash them in soapy water and then disinfected them by dipping them in a solution containing one part chlorine bleach and nine parts water.
Take the same precaution when propagating your geranium plants from cuttings.
Pots and containers selection
You can grow your geraniums in large pot containers, window boxes, or hanging baskets. There are two factors to consider when selecting the best pot planter. You first need to consider the ultimate size of your geranium plant which should guide the size of the pot container.
Secondly, consider the drainage. Geraniums grow well in pots and planters with adequate drainage.
Selecting the right potting soil for your geraniums
While geraniums are not very particular about soil pH, selecting a neutral to slightly acidic soil will be beneficial. Also, they prefer potting soil that is moist, well-draining, and high in organic matter.
To achieve these properties, work a 3-4-inch layer of organic matter such as compost or peat moss into the soil before planting. Besides, ensure the composition has a coarse material such as sand or perlite. If this sounds too complicated, you can go for a professionally prepared commercial soil mix.
The main advantage of such potting mixes is natural and enhanced with myco-tone which improves root development. However, if you go for this option lookout for fungus gnats especially when you keep the soil too moist.
Light and temperature exposure
Light and temperature are the essential aspects of any plant growth. If you want to have the best flowering and most vigorous geranium plants, place them in bright light. Although some geranium types can tolerate partial to full shade, they won’t blossom as you would expect.
If you don’t have enough light in your area, the best option would be to plant foliage geranium. Besides the light, you need to grow your geraniums in temperature ranges of 70-75 degrees during the day and 60-65 degrees at night.
If you don’t meet the light and temperature required, the plants will become tall and spindly. For optimum flowering and growth, geraniums should receive at least 6 hours of direct sun. The best locations for your geraniums especially during the winter months are south and west-facing windowsills.
Where this doesn’t help, you may need to consider the use of artificial light. Also, to promote bushy compact growth and avoid legginess, pinch the stems to encourage more lateral growth.
Watering potted geraniums
As a general rule, potted plants require more frequent watering. So water as soon as the top inch of the soil gets dry to the touch. Allow the soil to dry completely between watering, then water thoroughly. Use mulch to help retain moisture and prevent weed growth.
During the winter when the plant growth slows down, water much less, but do not let the roots dry out. You should avoid overhead watering as much as possible since wet foliage encourages disease development.
When it comes to geranium care, it’s best practice to inspect your plant each day to make sure it has enough moisture. Geraniums respond favorably to having the soil dry out somewhat between each watering.
Water only as needed, checking the soil for dryness to a depth of 4 to 6 inches. If you need a detailed guide on how to water potted plants, check out this article.
As a best practice, don’t fertilize your geranium plants until they are well established and when they are not actively growing (in winter). When you do fertilize, use soluble or slow-release fertilizers which are best for indoor plants.
You can fertilize every 2 weeks using a water-soluble fertilizer at half strength. If you’re growing your plants where light intensity is low or indoors, reduce the amount of fertilizer accordingly. Apply fertilizer according to directions on the label, and make sure that the soil is moist before applying.
An ideal scenario would be to fertilize your geranium plants with a liquid fertilizer that's a 20-20-20 formula, using a rate of 2 tablespoons per gallon of water. But again, it’s better to follow the instructions on the label carefully.
Pruning and deadheading your geraniums
Deadheading the spent flowers is the best way to keep geraniums blooming continuously throughout the summer. Frequently remove the spent flower heads as they begin to wither and deteriorate. This will prevent seeds from forming and force the plant into producing additional blooms.
How to deadhead geraniums
To deadhead your geraniums, rather than simply pulling off the top flowers, you need to go a little deeper in the plant and snap the stem below its node or joint, where new growth begins.
You can use a pair of shears—or simply use your hands. It is helpful to have a healthy plant that has been well-watered over time to make the stems easier to snap.
Cutting back geraniums will encourage new, full blooms to grow in and replace any that look weak or less full. Work through your plant, doing this throughout its sections. You’ll begin to see fresh new blooms in just a few days.
The entire process takes just a few minutes but can help your plants to last for weeks and even months longer. You can do this every couple of weeks, or if you have the time pull a few stems each day while tending to your plants.
Geraniums are not frost-hardy just as they’re sensitive to the summer heat. You should bring them under a shelter for them to survive. This is especially important if you had placed your potted geraniums outdoors.
To overwinter your geraniums, inspect all your plants and trash any plants with evidence of insects or diseases. For the remaining healthy plants, cut back the top to 6 inches in height, and place it in a sunny window. You can return the pots outside once the danger of frost has passed.
Managing pests and diseases
The best strategy for dealing with plant pests and diseases is to not have to deal with them in the first place. And the best way is to always prevent their infestation or infection.
You can achieve this if you keep geranium plants healthy by providing appropriate nutrition, observing watering best practices, and pruning where necessary. Pests have a strong sense for weak struggling plants. If you follow what we’ve discussed so far, you won’t have major issues.
Insects that frequently attack geraniums include aphids, cabbage loopers, mealybugs, caterpillars, mites, whiteflies, and fall cankerworms. The four-lined plant bug, scale, and slugs can also cause damage. Regularly monitor your plants and get rid of the infested plant parts and bugs.
Other disease problems to watch out for include bacterial leaf spot caused by the bacterium Xanthomonas pelargonii and is especially prevalent in warm, wet weather where plants are grown in crowded conditions.
Another common disease is botrytis blossom blight/leaf spot – a fungal disease. You can manage both of these diseases by removing old flowers as soon as they start to fade, and providing good air circulation. Others include gray mold, rust, and viruses.
You can check out this guide on geranium diseases to learn more on how to identify the various disease symptoms, their causes, and management.
Geranium Care and Common Problems
Geranium leaves turning yellow and brown
If the geranium leaves are only turning yellow, it may indicate nitrogen deficiency. However, if the yellowing is accompanied by brown discoloration, then, you need to watch your watering. Since this indicates overwatering.
Geranium plants appearing tall and spindly
When the plants begin to look spindly and taller than usual, it is a clear indication that they are not getting enough light. Expose them to bright light. If the weather is good, you may bring your plants outside for some sunshine.
Besides, you can cut back a few stems to encourage compact and bushy growth.
Blister-like growths on the undersides of geranium leaves
This is most likely to be geraniums Edema caused by overwatering and high humidity, resulting in small, corky cell production on the leaves. Luckily, Edema is not caused by an insect or disease pathogen but rather it’s a physiological problem.
Affected leaves develop small blisters on their undersides. The blisters rupture and turn tan or brown and become corky. Seriously affected leaves may turn yellow and fall from the plant. While this condition is unsightly, it does not cause serious harm to affected plants.
To control Edema on geraniums, reduce watering especially during cloudy weather and increase light levels.
You’ve just read an in-depth guide with actionable geranium care tips. I hope you’ve enjoyed reading just as much I enjoyed writing it for you.
To summarize, potted geraniums are excellent indoor plants that you can grow indoors throughout the year. With the right conditions, they will flower continuously giving your home a colorful jungle vibe.
There are several geranium types to choose including vining and hanging basket cultivars. You can purchase them in various stages of growth and in many different types of containers. The only problem facing you right now is choice!
All the best and hopefully these geranium care tips will come in handy.