Why are Primrose Leaves Turning Yellow?
Yellowing primrose plants can be attributed to a few causes. One common and easily treated problem is improper watering. Primroses need moist but not waterlogged soil. Make sure to water them regularly, but plant them in soil with good drainage to ensure they don’t stand in water, which can cause root rot and yellowing leaves. By the same token, don’t let the soil dry out, as this can cause yellow, brittle leaves. Two exceptions to this basic rule are the Japanese and drumstick primrose, which can both thrive in very wet soil. Leaves may also turn yellow if your plant is in direct sunlight. Primroses can tolerate direct sun in places with very cool summers but, in most cases, it’s best to plant them in partial or filtered sunlight.
Diseases That Cause Yellowing Primrose Plants
Not all causes of yellowing primrose plants are environmental. Various varieties of fungal rot are manifested in the production of smaller leaves that turn yellow and wither quickly. Remove and destroy infected plants to reduce the spread of the rot to healthy plants. Improving drainage may also help combat it. Leaf spot is another disease that appears as yellow to brown spots on the undersides of leaves. Leaf spot can be combatted by the application of fungicides or the simple removal of infected plants or leaves. Mosaic virus can be transmitted by aphids and appears as a yellow mottling on leaves that are often very stunted. The virus is not serious but is easily spread, so remove and destroy infected plants to prevent further infestation.