Dying Lobelia – 5 Most Common Causes & How To Fix
Is your lobelia or seedling showing signs of death? Symptoms of dying lobelias could appear in many forms including leaf discoloration, changes in leaf shape (wilting, drooping), slowing or stunted plant growth, and the surfacing of roots. Here are the main causes of dying lobelias and remedies that may help with the plant’s revival.
1. Incorrect watering and soil drainage
Incorrect watering tends to be the most common reasons for dying lobelias. It’s easy to get the watering frequency and volume wrong as how much water a lobelia needs will be different per season.
Generally speaking, lobelias need to be watered once a week. They are perennial plants that originate from southern Africa where rainfall is minimal. Overwatering can suffocate the plant roots and lead to its demise, while underwatering will cause the lobelia to dry out and prevent it from absorbing and distributing important nutrients from the soil.
How you water the lobelia now, however, is not going to be consistent for the rest of the year. You will need to up the watering frequency when the weather gets hotter (or sunnier) as well as reduce the frequency when the weather gets cooler.
The state of the soil is also important in this context. Soil with drainage problems, for example, would cause overwatering problems even if you were to only pour a small amount of water. Repotting might be necessary if the soil is too compacted or soil aeration might be needed if the plant is too heavy or big to be easily moved.
2. Lack of nutrients in the soil
Plants like lobelias also need a healthy balance of nutrients to thrive. There isn’t an infinite amount of nutrient in the soil. You will need to replenish the nutrient from time to time. Otherwise, the nutrient deficiency will cause many of the visual symptoms that appear when lobelias start to die.
Fertilizer or plant food is usually selected based on the NPK (nitrogen, phosphorus, and potassium) ratio. For lobelias, the preferred NPK ratio is 10-10-10. How often you fertilize the soil will depend on a number of factors such as the soil medium and the maturity of the plant. It’s important to note that over-fertilizing can also be a bad thing and may indirectly contribute to a plant’s death. You could use a soil testing kit if you want to learn more about the current state of the soil.
3. Too much or too little sunlight
Here’s another case where too much of something we perceive as good can be a bad thing. Too much sunlight, especially if it’s full or direct sun, can cause the lobelia to die off. The stress from prolonged exposure to sunlight can dehydrate the plant and also lead to leaf scorching or leaf tip burn.
As a general rule of thumb, lobelias prefer about at least 4 – 6 hours of direct sun. On the flip side, too little sunlight can also cause plants to die as it would inhibit their ability to photosynthesize and produce energy. Keep this mind when the days get shorter. In such cases, it may help to re-position the plant in an area that gets more sunlight exposure.
4. Damage from pests
Pest control is part and parcel of growing lobelias. There are a number of pests that are known to attack lobelias including mites and aphids. The pest control solution you use would depend on the type of pest you are dealing with. There are a number of natural remedies available if you want to grow the lobelia via organic means. This may include the use of products such as food-grade diatomaceous earth, which has exploded in popularity in recent years.
5. Infected by plant disease
Your plant could be dying because it’s infected with some form of plant or fungal disease. Root rot, for example, is dangerous and it’s hard to revive a plant that has it. Your lobelia could also be affected by other diseases like powdery mildew, rust, and black spots.