Your beautiful Magnolia stellata, with its delicate star-shaped blossoms, is a true sign of spring. But what if those lovely green leaves are starting to look a bit, well, anaemic? If you notice a pale green or yellowish discolouration between the veins of your magnolia’s leaves, while the veins themselves remain dark green, you may be experiencing a manganese (Mn) deficiency.

Manganese is a vital micronutrient for plants, crucial for processes like photosynthesis and enzyme activation, and when it’s lacking, your magnolia’s ability to thrive is significantly impacted.

This distinctive interveinal chlorosis is often a sign that your magnolia isn’t getting enough accessible manganese from the soil. The most common culprit is a high soil pH (alkaline soil), which makes manganese unavailable to the plant, even if it’s present. Magnolias prefer slightly acidic to neutral soils, so if your soil is too alkaline, your plant simply can’t absorb the manganese it needs. Other factors like poor drainage or excessive phosphorus can also contribute.

To fix this, the primary step is to address your soil’s pH. A soil test will confirm if this is the issue; if your soil is too alkaline, gradually lower its pH by incorporating acidic organic matter like an ericaceous peat free mulch or an ericaceous feed.