A magnesium deficiency first becomes visible at the oldest leaves. Here small rust coloured or cloudy yellow spots will appear. Dead spots may also occur and leaf tips will curl up. As the spots spread, the leaves will turn more yellow. This causes the plant to look more and more tattered. In this stage you'll also see colouring of the young leaves and a decrease in fruit production.
How do you recognise a magnesium deficiency?
- Yellow-green to yellow discolouring between the veins.
- Yellowing and brown spots on older leaves.
- The plant will create less fruits and flowers.
- The stems of leaves will turn purple.
- The tips of the leaves curl up.
What is the (possible) cause?
- The pH value of the soil or substrate is too low.
- The root environment is too cold or too wet.
- The root system of your plant is underdeveloped.
- The EC value of your soil or substrate is too high.
- There is too much nitrogen, potassium and calcium in the soil or substrate.