What to do when Rhubarb plant leaves turn yellow & fall off
The leaves of rhubarb plants can turn yellow and brown for reasons within or beyond your control. Here are the most common causes and steps you can take to make the foliage of the rhubarb plant look green and healthy again.
Underwatering or overwatering is bad for Rhubarb plants
Improper watering is usually the main culprit when yellow or brown leaves start to develop on rhubarb plants. Plants like rhubarb plants typically need regular watering to be able to mature and produce a good yield.
Underwatering, as a result, may cause the leaves to turn yellow if a key ingredient of photosynthesis goes missing. Overwatering may also lead to the same effect. Too much water can clog the soil and prevent the roots of the rhubarb plant from accessing oxygen found in the small pockets of air in the soil. Prolonged exposure to overwatered soil conditions will eventually lead to root rot and cause leaves to turn yellow and fall off.
Proper drainage of water from soil
You won’t be able to properly gauge the frequency of watering the rhubarb plant needs if it is being grown in soil that doesn’t drain well. Compacted soil can cause a number of issues for rhubarb plants such as preventing root growth, reducing nutrient absorption, and preventing oxygen absorption. All of this can cause leaves to turn yellow and fall off. you will know if the soil is waterlogged by creating a tiny hole on the soil surface and filling it with water. If the water hasn’t drained after a few hours then you are dealing with clogged soil problems.
To stop more leaves from turning yellow, you will most likely need to transplant the rhubarb plant into soil that drains well. One way of doing this is by mixing the soil with material like perlite, compost, and shredded leaves.
Excessive sunlight or lack of sunlight
Yellow leaves can also form on rhubarb plants due to changes in sunlight conditions. Prolonged exposure to direct sunlight, for example, can harm plants because it can result in sunburn and the scorching of leaves. Lack of sunlight could have the same negative effect on rhubarb plants as it would result in the leaves not getting enough light to drive photosynthesis. Lack of energy would then cause the leaves to wilt and gradually become discolored.
Try to position the rhubarb plant or provide it enough cover or exposure so that it receives an optimal amount of sunlight, which is about six hours of sunlight per day.