Geraniums are a popular flower known for their bright and cheerful blooms that adorn gardens, window boxes, and hanging baskets. However, you may notice the leaves turning brown, which can be concerning. In this article, we’ll explore the common causes of geranium leaves turning brown and provide tips to resolve the issue.
Table of Contents
Common Causes of Brown Leaves on Geraniums
There are a few key reasons why the leaves on your geranium may be turning brown:
Underwatering
The most common cause of geranium leaves turning brown is a lack of water. Geraniums prefer consistently moist soil and periods of dryness can cause the leaves to yellow, dry out, and eventually turn brown.
Fix: Check the moisture of the soil regularly by using a moisture probe. Water plants thoroughly whenever the top inch of soil becomes dry. Geraniums may need watering daily during hot, dry weather. Ensure pots and planters have adequate drainage holes on bottoms as soggy soil can also cause leaf problems.
Low Nutrient Levels
If geranium leaves are yellowing along with the browning, it can point to a nitrogen deficiency. Without enough nitrogen for photosynthesis, the leaves will become chlorotic (yellow) and then turn brown.
Fix: Apply a balanced liquid fertilizer monthly during the active growing season. An all-purpose 10-10-10 fertilizer is ideal for container geraniums.
Improper Soil pH
If the soil pH drops too low and becomes too acidic, it can cause iron and manganese toxicity resulting in brown leaf edges. This usually only occurs in alkaline soils.
Fix: Test the pH of the potting soil with an inexpensive soil pH tester. The ideal pH level for geraniums is between 6.0-6.6. If too acidic, mix some dolomitic lime into the soil to raise pH gradually.
Salt and Mineral Buildup
The salts, chlorine, and fluoride found in tap water can accumulate in potting soil over time. This buildup can scorch and dry out geranium foliage.
Fix: Water plants with rainwater or distilled water when possible to prevent buildup. Occasionally leach the soil with water to remove excess mineral salts.
Caring for Geraniums to Prevent Leaf Problems
With proper care and favorable growing conditions, geranium leaves can thrive without browning:
- Plant in well-draining potting soil and containers with drainage holes
- Water thoroughly when the top 1” of soil is dry
- Apply balanced liquid fertilizer monthly during the growing season
- Ensure 6-6.5 pH level with a soil test and amendments if needed
- Provide at least 4 hours of direct sunlight daily
- Prune spent blossoms to encourage new flowers
- Propagate new plants from healthy cuttings in late summer
What To Do If Leaves Become Brown
If despite your best efforts some geranium foliage becomes brown:
- Clip off the damaged leaves at the base
- Check soil moisture and pH
- Assess sunlight exposure and move the container if needed
- Apply chelated iron supplement to nourish the remaining foliage
- Monitor for pest infestations like whiteflies
With some troubleshooting and adjustments to care, your geraniums should perk back up and grace your containers with vibrant blooms and healthy-looking leaves once again. The key is attending to their basic water, nutrient, sunlight, and soil pH needs.
Gardening is my passion and growing plants indoors has always been a stress relief for me. Grow a banana tree in my apartment once (although failed to produce bananas).
