Pelargonium radens — a medium houseplant, prefers full sun light
SPECIMEN · FROM THE LIBRARY
Pelargonium radens

Pelargonium Radens

Updated · 8 observations
ON THIS PLANT

Pelargonium radens, the rasp-leaf pelargonium is a species of Pelargonium. It is in the subgenus Pelargonium along with Pelargonium crispum and Pelargonium tomentosum.

A note from PlantMom

Rasp-leaf pelargonium is fairly disease-resistant and typically not inclined to suffer from illnesses. Still, it can be affected by pests and diseases present in its environment. When infections occur, they are generally mild. Regarding care, this plant demands a moderate level of attention. It should be pruned regularly to preserve its appearance and encourage healthy growth. Applying fertilizer can also assist in increasing blooms. Rasp-leaf pelargonium is well suited for anyone with outdoor areas like a garden or patio and does not need extensive gardening experience. It may need extra care if kept indoors.

— PlantMom
CARE GUIDE

How to keep Pelargonium Radens.

Light

Rasp-leaf pelargonium prefers strong sunlight for healthy growth but can tolerate some shade. Insufficient light may reduce flowering and overall growth, while too much light can scorch the leaves. Native to habitats with abundant sun, it is worth noting that different growth stages may require varying light intensities.

Water

The rasp-leaf pelargonium thrives in subtropical environments where there is regular rainfall, as it prefers consistent moisture. To keep it healthy, it is important to water it weekly, as it does not tolerate too much dryness or overwatering. Being an evergreen plant, it retains its leaves throughout the year, making it ideal for indoor cultivation with steady watering.

Temperature

Rasp-leaf pelargonium originates from habitats with temperatures between 68 and 100.4 °F (20 to 38 ℃). Preferring warmer conditions, it will require special care during colder seasons to remain within this comfortable range.

Fertilizer

Timing is important for fertilizing Rasp-leaf pelargonium. Apply fertilizer in early spring and continue monthly until early summer. Fertilizer encourages attractive blooms and supplies energy during both dormant and active growth phases.

Pruning

The rasp-leaf pelargonium is known for its aromatic leaves and pink flowers. To keep the plant healthy and vigorous, it benefits from regular pruning, which is best done between late winter and early spring. Pruning encourages bushier growth, improves airflow, and helps prevent diseases. Be sure to use clean, sharp tools when trimming the plant to maintain its health and shape.

Pot & Repot

Repot your rasp-leaf pelargonium every 2 to 3 years in the spring. Use a medium-sized pot to encourage healthy growth. Opt for well-draining soil, and water the plant moderately, as it thrives with consistent moisture. Position it in a location with bright, indirect light to support recovery and growth while helping it maintain a compact form.

CHARACTERISTICS

Botanical profile.

Plant Type
Herb, Shrub
Life Cycle
Perennial
Genus
Pelargonium
Family
Geraniaceae
Hardiness Zone
8-11
Mature Height
1.52 m
Mature Spread
20 cm to 30 cm
Leaf Color
Light Green, Dark Green
Leaf Type
Evergreen
Flower Color
Pink
Flower Size
1.27 cm
Bloom Time
All year round
Planting Time
Spring, Summer, Autumn
Harvest Time
All year round
Native Area
South Africa
ALSO KNOWN AS

Other names.

en Mutifid-leaf pelargonium en Rasp-leaf pelargonium en Crowfoot geranium en Curlyleaf geranium
FREQUENTLY ASKED

Reader questions.

How should I water my Rasp-leaf pelargonium plant for best results?

Your Rasp-leaf pelargonium is not fussy when it comes to watering. You can use any common watering tool such as cans, hoses, or even cups to water this plant. Regardless of the tool, make sure to water the soil directly and evenly to reach all parts of the root system. Filtered water is better than tap water as it may have harmful particles for plants. Using water that is at or slightly above room temperature is also recommended to avoid shocking the plant. However, the Rasp-leaf pelargonium usually responds well to any kind of water.

Why should I add fertilizer to my Rasp-leaf pelargonium plant?

To enhance the growth and beauty of your Rasp-leaf pelargonium, it is important to fertilize it for several reasons. The most obvious reason is that fertilizer promotes the production of lovely blooms. Fertilizing in early spring is particularly beneficial as it ensures excellent flower quality during that season. Additionally, fertilizer provides your Rasp-leaf pelargonium with ample energy that it can store in the ground during its dormant growth phases. By providing extra nutrients during the fall planting process or late spring, you can help your Rasp-leaf pelargonium conserve more energy to utilize once active growth resumes.

How many hours of sunlight per day does Rasp-leaf pelargonium need for healthy growth?

To ensure healthy growth, it is important to provide Rasp-leaf pelargonium with a minimum of 3-6 hours of sunlight daily. Although most plants that tolerate partial sun can also do well in full sun, Rasp-leaf pelargonium can adapt better because it requires less light for photosynthesis.

What temperature is best for Rasp-leaf pelargonium?

Plants are affected by cold temperatures because they reflect the temperature of their surroundings. When they are in the sun, they can warm up, but this doesn't happen in winter. The Rasp-leaf pelargonium thrives in temperatures between 70~85℉(21~30℃), although it can withstand temperatures as low as 20~30℉(-6~0℃), or even 15℉(-10℃) for a short time. However, prolonged exposure to such low temperatures can lead to frost damage. To ensure the best conditions for this plant, aim for maximum temperatures between 70~85℉(21~30℃), and remember to spray them with water occasionally and provide some shade to prevent wilting.

What should I do if I give my Rasp-leaf pelargonium too much or too little water?

Outdoor plants, especially newly planted ones or seedlings, are often prone to not getting enough water. It's important to remember to keep watering them consistently for a few months, especially when the tree is small or has just been planted. Once the roots are established, Rasp-leaf pelargonium plants can rely on rain most of the time. When Rasp-leaf pelargonium is planted in pots, overwatering is more likely to occur. If you accidentally overwater your Rasp-leaf pelargonium, there are steps you can take to remedy the situation. First, stop watering the plant immediately to minimize the effects of overwatering. Then, remove the Rasp-leaf pelargonium from its pot to inspect the roots. If no root rot is present, you can return the plant to its container. However, if root rot is evident, trim away any affected roots and consider applying a fungicide to prevent further damage. Finally, repot the Rasp-leaf pelargonium in well-draining soil. In the case of underwatered Rasp-leaf pelargonium, simply water the plant more frequently. Underwatering is often an easy fix, as the plant's leaves will droop, dry out, and fall off. After sufficient watering, the leaves will quickly regain fullness. It's important to correct your watering frequency as soon as you notice underwatering.

When should I fertilize my Rasp-leaf pelargonium plant?

It is important to time the fertilization of Rasp-leaf pelargonium correctly. If you apply fertilizer too early while the plant is still dormant, it won't be utilized effectively and will be washed away by rainwater, leading to waste and pollution. The first application of fertilizer should be made in early spring, and then continue to fertilize once a month until early summer.

What kind of sunlight does the Rasp-leaf pelargonium plant need?

Rasp-leaf pelargonium thrives in full or part sun. It flourishes when exposed to direct morning light, but during summer it requires shielding from intense afternoon sun. Excessive hot afternoon sun in temperate climates can scorch the leaves, resulting in a negative impact on the plant's aesthetic and well-being.

Do I need to change the temperature for Rasp-leaf pelargonium when it's growing in different stages?

To successfully grow Rasp-leaf pelargonium, it is important to research and ensure the right temperature conditions. Some growers may lower their plants' thermostats to save on HVAC costs during the growing season. However, it is crucial to understand that temperature can impact flowering, pest management, and overall plant quality. During the winter, certain species of Rasp-leaf pelargonium may enter a dormant state, causing growth to stop. As the seasons change, the base temperature increases, allowing Rasp-leaf pelargonium to grow faster. Species naturally found in warm habitats have higher optimum temperatures compared to those thriving in cooler climates. Exposing Rasp-leaf pelargonium seeds to cool temperatures can lead to reduced uniformity and delays. Lowering the temperature during flowering, but not at other stages, may be beneficial. Cooler nighttime temperatures also require less water, so adjust irrigation accordingly.

How often do I need to water my Rasp-leaf pelargonium?

To successfully grow most outdoor plants, natural rainfall is usually sufficient. However, if your area doesn't receive enough rain, you'll need to water your plants every 2 weeks in the spring and fall, and more frequently in the summer. In the winter, plants grow more slowly and require less water, so you should water them sparingly or not at all. Young or newly planted Rasp-leaf pelargoniums may need more frequent watering to help them establish and grow into drought-tolerant plants. For potted plants, there are two main approaches to determine watering frequency. The first is to follow a set schedule, such as watering once a week or every other week. However, this may not take into account the specific conditions of your Rasp-leaf pelargonium's environment. Another option is to assess soil moisture before watering. Wait until the top 2 to 4 inches of soil, about one-third to half the depth of the pots, have dried out completely before giving more water. This method allows you to adjust watering frequency based on the season and the plant's water needs.

When is not a good time to fertilize my Rasp-leaf pelargonium?

To ensure optimal growth and blooming of Rasp-leaf pelargonium, it is important to pay attention to the type and timing of fertilizer application. Avoid using a fertilizer high in nitrogen as this can promote excessive leaf growth while inhibiting blooming. Instead, opt for a fertilizer that has a lower nitrogen content relative to other nutrients. In addition, it is advisable to refrain from fertilizing the plant after early autumn to prevent excessive growth before winter. Furthermore, avoid fertilizing Rasp-leaf pelargonium during hot and dry periods, as dry soil does not effectively deliver the fertilizer and stimulating growth may further increase the need for water that might not be readily available. It is advisable to apply fertilizer during cooler temperatures earlier in the season. Lastly, be cautious when applying fertilizer near other plants or lawns, as Rasp-leaf pelargonium can absorb excess fertilizer, potentially causing harm.

Can the sun harm Rasp-leaf pelargonium? How can we shield Rasp-leaf pelargonium from the sun and heat?

When moving rasp-leaf pelargonium plants from indoors to outdoors, it's important to avoid direct sunlight which can cause damage. To prevent sunburns, gradually transition the plants from a shaded area to a brighter spot. However, even if the plants are accustomed to the sun, extreme heat can still harm them. During a heatwave, it's crucial to keep the soil consistently moist to help the plants handle the excessive heat. To protect sensitive rasp-leaf pelargonium during extreme weather events, consider moving them to shaded areas in the afternoon or using a shade cloth.

How do I keep Rasp-leaf pelargonium warm when it is cold outside?

To help the plant withstand colder temperatures, it's important to stop fertilizing so new growth doesn't occur and the existing leaves can become hardier. To keep the plant warm, you can create structures like cages or trellises around the Rasp-leaf pelargonium. Another option is to use heat mats to gently warm the soil, which can maintain the ideal temperature range for the plant.

PLATES
Pelargonium radens flower
PLATE 01 · flower
Pelargonium radens flower
PLATE 02 · flower
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