Keep your plant’s leaves healthy and disease-free with ideas from this quick troubleshooting guide.
There’s more to a geranium than beautiful blooms. The leaves can play an equally outstanding role in the attractiveness and overall appeal of the plant. Most home gardeners grow common or zonal geraniums. Unsightly problems can arise on the foliage of these iconic plants when conditions are not as they should be.
Garden Geranium Leaves
On common garden or zonal geraniums — the kind that feature ball-shaped blooms — you’ll find green foliage near the base of the plant. These leaves have large, rounded edges that might remind you of an oversized clover. They are referred to as zonal geraniums because of the dark semi-circle-shaped bands seen on their leaves. Zonal geraniums may also be grouped with fancy-leaved geraniums. These leaves feature the same zones or bands of color but with more intensely pronounced hues, including burgundy, white and yellow. This is a very distinctive feature of their marking and should not be confused with a sick or diseased plant. One other factor than can help to identify fancy-leaved geraniums are the sharp, pointy edges seen on the leafs, rather than the rounded leaves you’ll find on zonal geraniums.
When Leaves Turn Yellow
Overwatering is one of the most common causes of leaf yellowing. If the plant is not dead, stop watering it for the time being and allow it to dry out before watering again. Continue to repeat this cycle for healthy growth and the leaves should return to normal.
Yellowing could also be a result of a drop in temperature or a nutrient deficiency. Just as geraniums don’t like too much water, they prefer warmer temperatures. If they are potted in containers and you see there will be a late season cold snap, bring them indoors to help prevent yellowing. As for nutrient deficiencies, consider using a water-soluble fertilizer once per month to make sure your geraniums are receiving the proper nutrients.
When Leaves Turn Red
Reddish leaves on your geranium plant could be a result of the nutrients available in your soil. Have your soil tested to see what is lacking or use a pre-mixed potting soil that has the proper amendments.
Some sources note that redness on geranium leaves may also be a sign of under-watering or a result of exposure to cold temperatures. Consider all of these factors, and try different remedies (i.e. adding nutrients to the soil, watering more frequently, or bringing the plants indoors during cold snaps) to troubleshoot and ultimately correct the problem.
If you notice spots on your leaves — rather than an overall, gradual change in color — or if you see fungal spores, these may be evidence of a disease. Any leaves with these features should be removed from the plant immediately. Monitor other leaves closely to see if the disease spreads or returns. Frequent deadheading may help to save the plant.
As with many plants, growing geraniums is all about balance. Consider their light, water, and nutrient needs and be attentive — but not overly attentive — to these.