Catmint, or Nepeta cataria, is a flowering plant of the family Lamiaceae. The plants comprise around 250 species native to Asia, Africa and Europe, and naturalized in North America. These aromatic herbs produce lavender-blue flowers and are fairly easy to cultivate. They are commonly used for herbal teas and insect repellents. Like most plants, they are also prone to conditions that cause yellowing leaves.
Catmint Leaves Turning Yellow: What Are The Reasons?
Drainage problems
Catmint leaves tend to turn yellow if the plant is experiencing drainage issues. This is often observed during periods of heavy rain or when you overwater the plants. See to it that the plants are properly in the ground, and have not been loosened by the water.
Either too much or too little water could cause young catmint leaves to turn yellow. Check the soil: if it feels dry, the plants require watering.
Nutrient deficiency
Catmint leaves could also turn yellow due to a nutrient deficiency. Nutrients that are essential to plants include nitrogen, magnesium and potassium. If any of these nutrients is lacking in the soil, the plants will not flourish and the leaves may turn yellow and wilted. Supplement with fertilizers that provide these nutrients to enrich the soil and encourage the healthy growth of the plants.
Ideally, you should also use a soil test kit to check the soil. Based on the soil test results, amend the soil and add the necessary nutrients to avoid further yellowing leaves.
Transplant shock
Catmint plants that are moved from their original living conditions to another area could experience transplant shock. The abrupt change in conditions can result in yellowing leaves. Transplanting during the growing season can minimize this situation, but will not entirely eliminate the potential for transplant shock. Monitor the transferred plants for a week to 10 days to see if the leaf color improves.
Stress
Catmint leaves may turn yellow due to stress brought about by environmental factors. This may include too much or too little sun, or strong winds. The area where you planted your plants could also be a factor, since they may not be suited to that particular area or soil. If this is the case, you need to transfer the plants to a more suitable spot or soil type for them to survive.
Protect your plants from too much sun by ensuring they have shade during the hottest part of the day. If strong winds are forecast in your area, secure your plants by placing them indoors or in a greenhouse.
Catmint Care
Catmint plants are easy to care for. They only need to be watered regularly until they become mature and well-established. Put mulch on the soil to retain moisture and to discourage the growth of weeds. When the plants reach a few inches tall, pinch them back to encourage bushier growth.
Catmint blooms from summer through fall, and to encourage further flowering, try to deadhead spent blooms. This will also prevent re-seeding. After harvesting the blooms and after the fall season, shear the plants back to half their size.
How To Grow Catmint
Catmint is ideal for mass planting and edging. It is best suited in areas near vegetables since it acts as an insect repellent, especially for pests like aphids and Japanese beetles. It is grown in full sun or partial shade and thrives in well-draining soil. Catmint is famous for being heat and drought-resistant which makes it a good choice for dry garden areas.
These plants are grown by seed or through division, with planting in springtime. They need plenty of space and should be spaced to at least a foot apart from one another. If they are planted too near each other, it could lead to leaf spots or powdery mildew which is prevalent during hot and humid weather. Some catmint varieties are aggressive, so you may need some edging around them.
Conclusion
Catmint plants are perennials that are popular for repelling insects and as herbal tea. They can also experience yellowing leaves, which may be attributed to stress or nutrient deficiency. However, it could also be due to stress, transplant shock or drainage problems.
Image: istockphoto.com / Tatiana Kuklina