The Causes of Yellow Leaves on Geraniums

Water

• Yellow leaves are often a sign of overwatering. Geraniums should be watered when the soil is dried out. While the surface of the soil will dry out rather quickly, the true test of needing to water is determined by how moist the soil is beneath the surface. Stick your index finger about an inch deep into the soil and see how it feels. If it is still fairly moist you can wait a few days to water again. This is especially important if your geranium is planted in a pot as opposed to the ground. When you stick your finger about an inch into the soil and the soil is dry, it is time to water your geranium. Keep track of how often the soil is dry and after a few weeks you will know what your regular watering schedule should be. If the leaves are still yellow after correcting a possible over-watering issue, consider other factors that might be contributing to their color.

Fertilizer

• When overwatering is ruled out, consider whether you are using the proper amount of fertilizer on your geranium. Applying too much fertilizer can give a geranium too much nutrients and cause yellow leaves to form. Start by rereading the instructions on your fertilizer package and check to see if you are using too concentrated of a solution. Make sure you are adding enough water to your fertilizer solution and that you are only applying it as often as the package instructs you to. Most fertilizers need only be applied once per week. If you are applying fertilizer to your geranium more often than that, chances are that you may be causing the leaves to yellow. Back off the fertilizer and see if the condition improves.

Location

• A final consideration is the location of your geranium. If it is in a pot, the geranium may be outgrowing its current pot and need to be moved to a larger one. If the plant is spilling out of the pot and appears crowded or crammed, move it to a bigger pot with new potting soil. Over time, salts from hard water deposits and fertilizers can build up in the soil of a potted plant. If the leaves on your geranium are still yellow after you've ensured that watering and fertilizer are in order, consider repotting the plant with new potting soil in the same, or larger pot, if necessary. The cause of yellowing leaves on a geranium may also be root rot or bacterial disease in the soil. Cut away the completely yellow portions of the plant and repot it with new potting soil. Consider adding vermiculite to the soil if it is very dense to help water drain better through the pot.