How To Keep Geranium Leaves Green (7 Methods)

Geraniums are highly sought-after flowering plants that produce attractive pink, purple, white, or red blooms, adding a Mediterranean cheer to your garden or flower bed. They are easy to grow and maintain and have eye-catching, scented foliage. However, you might be wondering how to keep the leaves of your geraniums green throughout the growing season.

Here are 7 effective ways of keeping geranium leaves green:

  1. Plant your geraniums in suitable soil.
  2. Avoid overwatering or underwatering.
  3. Keep your geraniums well nourished.
  4. Protect your plant from pests and diseases.
  5. Meet your geraniums’ sunlight requirements.
  6. Protect your plant from cold snaps.
  7. Avoid using herbicides.

This article explores various methods of maintaining the green color of geranium leaves. So, keep reading to learn more.

1. Plant You Geraniums in Suitable Soil

Geraniums (pelargoniums) are perennial flowering plants that can also grow as annuals. These gorgeous plants have evergreen leaves if planted in suitable soil during their growing season. Therefore, any yellowing or discoloration of the leaves could mean an issue with the soil or potting mix.

Understand Your Species of Geranium

However, before we explore this possibility further, it’s essential to note some facts about geraniums:

What most people in the US refer to as ‘geraniums’ are actually pelargoniums. Both are genera of flowering plants that belong to the Geraniaceae family and have some similarities.

But a distinct difference between the two plants is that true (hardy) geraniums have five similar petals. In pelargoniums, the upper two petals are different from the lower three, giving them a pom-pom appearance.

So, in this article, we’ll focus on the geraniums (storks bills) in the genus Pelargonium.

Plant Geraniums in Well-Draining Soil

Although geraniums can grow in any soil type, they thrive in rich, well-draining soil with medium moisture. Since they lack an extensive root system, the plants will do well in porous soil where the roots can breathe and absorb minerals. And potted geraniums don’t mind shallow containers since their roots don’t grow deep into the soil.

Planting your geraniums in compact, waterlogged soil will harm your plants’ health since the roots can’t absorb nutrients from the soil. The roots also can’t translocate dissolved nutrients to other parts of the plant. As a result, the leaves won’t receive their share of nutrients from the root system, turning yellow.

If you’re growing your geraniums outdoors, it would be best to plant them in loamy soil since they are rich in organic matter and well-draining. Your plants will thrive, and their leaves will remain green throughout the growing season.

However, if this soil type is unavailable, adding compost to your garden soil is a suitable way to improve its drainage. You can spread a compost cover of about 2-4 inches (5-10 cm) to the upper 6-12 inches (15-30 cm) of your soil. 

Consider Using a Potting Mix

If you want to grow your geraniums indoors or on overhanging baskets, a soilless growing medium (potting mix) would be ideal. However, you must ensure that it is best suited for your plants such that it doesn’t drain too rapidly or retain a lot of moisture.

Also, ensure that the potting mix has the correct pH since geraniums prefer a pH range of 5.8 to 6.5. Some potting mixes with peat might be too acidic, and you might have to add some lime to neutralize them a bit.

If you prefer growing your geraniums in raised flower beds, it’s preferable to mix your garden soil with the potting mix to ensure proper drainage. However, some gardeners prefer using commercial raised bed soil since it has the perfect consistency and drainage.

2. Avoid Overwatering or Underwatering

Geraniums are hardy, drought-resistant plants. Nevertheless, they love to grow in soils with medium moisture. It’s challenging for most gardeners to find the right water balance, and many either overwater or underwater their geraniums.

Signs That You’re Overwatering Geraniums

Some gardeners overdo the watering, and geraniums can’t stand it as these plants hate sitting in wet, soggy soil.

You’ll know that you’re overwatering your plants if you notice the following signs:

  • Yellowing of leaves, especially the lower ones
  • Pale water spots
  • Waterlogged soil

Most people tend to overwater their outdoor geraniums in spring or summer when there are some rainfall episodes. You might also overwater your indoor plants if the soil or growing container isn’t draining correctly.

You can adjust your watering routine depending on some factors, including the following:

  • Your soil type
  • The season and weather conditions
  • The growing environment

Only water your geraniums when it’s clear they need a drink. The best way to determine this is by doing a test using your fingers. If the top 2-3 inches (5-7.6 cm) feel dry, you can water your plants.

Ensure that you irrigate your plants by focusing on the roots—avoid wetting the leaves.

Signs That You’re Underwatering Geraniums

Since geraniums are drought-tolerant, they can bear an extended period of dryness or heat waves. However, this doesn’t mean you should neglect their water requirements. The plants need some water once in a while, and they’ll be stressed if they don’t get any for a long time.

You’ll know that you’ve underwatered your geraniums if you notice the following:

  • Yellowing of the leaf edges
  • Drooping leaves

It would be best to water your geraniums when the soil feels dry, as we’ve already established. Avoid drenching the soil since geraniums can’t stand waterlogged soil.

You might need to occasionally monitor the soil’s moisture to ensure that your plants have the correct amount. Consider using a meter to test the moisture levels.

3. Keep Your Geraniums Well-Nourished

Geraniums are moderate-to-heavy feeders. Like other flowering plants, they require regular feeding to grow healthy and bloom in time.

Geranium leaves are dark green when they have an adequate supply of nutrients, including nitrogen, potassium, phosphorus, iron, and manganese. 

They’ll start turning yellow or have other discolorations due to nutrient deficiencies. This phenomenon is common with potted flowering plants that have been growing in these containers for months or even years.

So, if you notice that your geranium leaves are turning pale green or yellow or have other discolorations, it’s crucial to determine if they’re undernourished. However, it’s confusing to tell the specific nutrient that your plants could be lacking, and it’s essential to know what to look out for.

Here’s a table that elaborates on geranium nutrient deficiencies and their symptoms:

NutrientRole in PlantDeficiency Symptoms
NitrogenEssential in plants’ growth and development
  • Light green lower leaves
  • Yellowing (chlorosis) of older leaves
  • Browning and death (necrosis) of leaf margins
PhosphorusProduction of proteins, DNA, RNA, and cell membranes
  • Initial darkening of leaves
  • Irregular red or purple spots on lower leaves’ margins
  • Browning and death of leaves in severe cases
PotassiumStarch formation, drought tolerance, pH stabilization, cell turgor, and enzyme activation
  • Leaves reduce in size and turn dark green
  • Necrosis of leaf margin
  • Browning of leaves, appearing scorched
SulfurProtein synthesis, respiration, and photosynthesisRemoving formed radicals, lignification, and formation of some enzymes and proteins
MagnesiumFormation of chlorophyll, enzyme and cofactor reactions, carbohydrate metabolism, stabilizing cell membranes
  • Yellowish-green chlorosis on leaf margins
  • Greenish-yellow chlorosis in lower leaves
Iron Chlorophyll, DNA, and RNA formation, formation of heme and sulfur proteins
  • Interveinal chlorosis (yellowing of veins) in young leaves
  • Widespread leaf chlorosis in severe cases
ManganesePhotosynthesis (formation of free oxygen radicals)
  • Yellowing in young and recently matured leaves
  • Necrotic stippling
ZincProtein synthesis
  • Yellowing of leaf veins
  • Dying leaf margins
CopperRemoving formed radicals, lignification, formation of some enzymes and proteins
  • Dull green appearance in leaves
  • Chlorosis in leaves

How to Deal With Nutrient Deficiencies

Nutrient deficiency occurs due to a lack of nutrients in the soil or growing media. It can also be due to leaching, overwatering, or pH fluctuations. Knowing why your geraniums are undernourished is essential to establishing the best remedy.

Here are effective ways to deal with nutrient deficiencies and keep the leaves of your geraniums green:

  • Use nutrient-rich soil or potting mix when planting your geraniums.
  • Fertilize newly planted (outdoor) geraniums every two weeks throughout their growing period.
  • Feed potted (indoor) geraniums every 4 to 6 weeks using a water-soluble fertilizer.
  • Repot geraniums that are growing in containers when they start wilting. 

Note: Apart from lacking sufficient nutrients in the soil (or growing medium), geranium leaves could turn yellow if the roots can’t absorb nutrients from the soil. To solve this issue, you can sprinkle some Epsom salt around your geraniums to boost the absorption of nutrients like nitrogen and phosphorus.

4. Protect Your Plant From Pests and Diseases

The foliage will maintain its green coloring if you’re feeding and watering your geraniums properly. However, these flowering plants are also susceptible to diseases that might cause leaf discoloration (among other effects).

It helps to know what diseases affect geranium leaves, their causes, and how to identify and treat them.

These diseases include the following:

DiseaseCause/PathogenSymptoms Remedy/Prevention
Southern bacterial wiltRalstonia solanacearum
  • Wilting leaves
  • Yellowing and necrosis (death) of lower leaves
  • Sterilization of cuttings and stock plants
  • Chemical control
Leaf rustPuccinia pelargonii-zonalis
  • Small, yellow spots on the leaf surface
  • Rust-colored spots on leaf undersides
  • Remove diseased plants
  • Use disease-free cuttings
  • Proper sanitation
  • Avoid overhead irrigation
Bacterial blightXanthomonas campestris pv. pelargonii
  • V-shaped lesions on leaf undersides
  • Yellow-brownish leaf spots
  • Use sterilized tools to cut plants
  • Avoid overhead irrigation
  • Remove and destroy infected plants
  • Chemical control
OedemaWater imbalance
  • Small water-soaked pimples on leaf undersides
  • Corky brown blisters
  • Leaf necrosis
  • Avoid overwatering in humid, cloudy weather
  • Space plants
  • Use well-drained soil (potting mix)
Pseudomonas leaf spotPseudomonas cichorii
  • Water-soaked spots (dark brown or black)
  • Yellow halo around the spots
  • Avoid overhead irrigation
  • Use disease-free cuttings
  • Keep leaf surfaces dry
Botrytis blightBotrytis cinerea
  • V-shaped lesions on leaves
  • Concentric rings on leaves
  • Use disease-free cuttings
  • Proper sanitation
  • Chemical control
  • Avoid overhead irrigation
Alternaria leaf spotAlternaria alternata
  • Concentric dark rings
  • Water-soaked spots on leaves
  • Avoid overhead irrigation
  • Fungicides
  • Remove plant debris
Viral diseaseVarious viruses, including Cucumber Mosaic Virus (CMV), Pelargonium Flower Break Virus (PFBV), Impatiens Necrotic Spot Virus (INSV)
  • Leaf spots
  • Leaf cupping and curling
  • Yellowing of veins
  • Leaf malformation
  • Ringspotting
  • Sunken purple-brown leaf lesions
  • Control insect and mite invasion
  • Plant disease-free, virus-indexed cuttings
  • Destroying infected plants
  • Avoid unnecessary handling of plants
  • Weed control

5. Meet Your Geraniums’ Sunlight Requirements

Geraniums are sun-loving plants. These attractive flowering plants thrive and will be evergreen if you meet their sunlight needs. The leaves might start yellowing if your geraniums aren’t obtaining enough sunlight.

Your geraniums will require 4 to 6 hours of sunlight daily to grow healthy and bloom in time. If you’ve planted your geraniums indoors, ensure that you place them at a location where they’ll access adequate sunlight—preferably the morning sun near an eastern window. You can then move them to a shaded, well-ventilated space from noon.

Alternatively, you can place them near a southern window, but pull the light curtains down at midday to shield your geraniums from intense sunlight.

If you’re growing these flowering plants outdoors, they’ll love to grow in full sun and can even survive a heat wave. However, geraniums will need some shade when the temperatures are extremely high, especially on summer afternoons.

6. Protect Your Plant From Cold Snaps

Temperature significantly affects geraniums’ growth and development, especially when it comes to the following key processes:

  • Photosynthesis
  • Respiration
  • Formation of flowers

Since they’re native to South Africa, geraniums love warm weather. In the US, they grow well in USDA plant hardiness zones 9 to 12, and their leaves remain green at optimum temperatures.

Geraniums planted in regions whose temperatures don’t drop below freezing point can grow as perennials (all year round). Those in areas experiencing harsh winter weather will only grow as annuals.

Annual geraniums will not withstand extended periods of wet and cool weather, and even a light freeze can be detrimental to their survival.

Generally, geraniums growing indoors need a temperature range of 65-70 °F (18-21 °C) during the day and 55 °F (13 °C ) at night.

On the other hand, outdoor geraniums can withstand daytime temperatures of about 65-75 °F (18-24 °C) and nighttime temperatures of 50-60 °F (10-16 °C).

Exposing your geraniums to temperatures below 50 °F (10 °C) for an extended period will result in stunted growth and delayed maturity. The leaves might start yellowing or showing reddish discolorations.

Outdoor geraniums are also vulnerable to frost damage, especially in early spring.

You can protect them from the harsh weather by taking a few extra steps:

  • Bringing them indoors and placing them in a dry space
  • Insulating them using cloches (bell jars), bedsheets (or blankets), and frost cloths
  • Watering your geraniums the night before spring frost

You should also be up-to-date with your region’s weather forecast to predict when you’ll expect the first frost.

Potted geraniums are more susceptible to cold snaps since their roots are shallower than in garden plants. As a result, they lose heat to the atmosphere when placed in a cold environment.

To protect your indoor (potted) geraniums, take care to follow these tips:

  • Keep them away from the windows to prevent any exposure to cold drafts.
  • Avoid placing them near AC vents.

7. Avoid Using Herbicides

Weeds are a nuisance to many farmers since they deprive plants of essential nutrients. They’re also invasive and aren’t a pleasant sight when they encroach on your garden or landscape.

Most people reach for herbicides to control weeds.

If you’ve planted geraniums, you might need to use herbicides to control weed infestation in your garden. Most herbicides will not harm your geraniums and will only kill the weeds.

However, this doesn’t mean there won’t be any side effects. In some cases, herbicides will injure your geraniums. The most common impact of herbicides on geraniums is the bleaching effect on the foliage, which is when the leaves will start yellowing or appear pale.

So, it would help if you minimized herbicide use on your geraniums and used alternative weed control methods:

  • Remove the weeds manually (and frequently).
  • Mulch your geraniums to discourage the growth of invasive plants.

Final Thoughts

Geraniums are drought-resistant and will thrive in warm weather. They also maintain their evergreen foliage when grown in optimum conditions. Unfortunately, some factors may cause yellowing and leaf discoloration, including diseases, water imbalance, and cold snaps.

Because of this, it’s important to adopt strategies to keep the leaves of your geraniums green throughout their growing season.

These include:

  • Watering them properly
  • Feeding them correctly
  • Protecting them from diseases
  • Meeting their sunlight requirements
  • Protecting them from cold snaps
  • Minimizing herbicide use

Dr. Moritz Picot

Dr. Moritz Picot is a horticulture enthusiast and the founder of TheGrowingLeaf.com, where he serves as the lead content writer. He established the website in 2022 as a valuable resource for both gardening aficionados and beginners, compiling all the gardening tips he has accumulated over the past 25 years. Alex has a passion for nurturing plants, transforming backyards into inviting spaces, and sharing his knowledge with the world.

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