After weeks if not months of patiently awaiting your seedlings growth, you may see tiny white spots on the undersides of some leaves. This is likely edema, a common issue faced by home gardeners. Edema isn't a major concern as it's relatively common in broadleaf plants like chillies, tomatoes, ivy, ferns, cacti, broccoli, and many others. However, if left untreated, plant edema can result in distorted leaves and unattractive fruits. In this article we'll illustrate what plant edema looks like and provide solutions for remedying the problem.
What Is Plant Edema & How to Identify it
Plant edema is a common problem where plant tissues struggle to retain water effectively, often because of environmental factors like poor air circulation, inconsistent watering schedules, irregular fertilization, or overcrowded plant conditions. Unlike bacterial or fungal issues, this disorder doesn't spread between plants. Symptoms of plant edema can include yellow bumps or blisters on the leaves, white crystalline deposits on the underside of leaves, and eventually brown dry patches where cells have broken down. Additionally, many affected plants may develop curled leaves.
What Causes Edema in Plants?
The primary cause of plant edema is the plant roots absorbing water faster than it can use or release through transpiration, resulting in visible signs of collapsed cells. Environmental factors contributing to this condition include poor air circulation, inconsistent watering schedules, irregular fertilization, and overcrowded plant conditions.
Can Plant Edema Spread?
Plant edema isn't caused by viruses or bacteria; rather, it's a cellular disorder triggered exclusively by environmental factors. Consequently, it doesn't transfer from one plant to another. However, certain plant varieties are more prone to edema. It can impact a wide range of broadleaf plants, such as chillies, tomatoes, ivy, ferns, cacti, broccoli, and numerous others.
How To Treat Edema in Plants
Aside from adjusting your plant's environment, think about cultivating a different variety less susceptible to edema. Avoid picking off leaves displaying edema symptoms as this could exacerbate the condition. Instead, focus on improving conditions by implementing the following measures.
Improve Air Circulation
This advice primarily pertains to indoor growers where it can be challenging to gauge the necessary air circulation. Improve air circulation by using a gentle fan to create a steady breeze and by opening vents or windows to allow fresh air into your growing area. Overcrowding plants in a confined space can cause stress. Make sure you have an air intake and exhaust system in place to maintain fresh air circulation. Indoors or in a greenhouse, ensure there's sufficient space between plants. While it may be tempting to cram as many seedlings as possible into your growing space, this approach almost guarantees problems later on.
Adjust your Watering Schedule
Ensure you avoid overwatering your plants. This practice can result in edema, where the roots absorb more water than the leaves can release through transpiration. This excess water can rupture cells, especially on the undersides of leaves, resulting in water-soaked patches that eventually become corky and unappealing. However, underwatering can also cause a variety of problems, so be sure to learn how much water your plant needs to thrive.