Sick leaf

Sometimes, plant leaves change colour during the growing seasons – spring and summer. There are numerous reasons for this, so you'll have to become a plant detective, to see what has caused this.


If plant leaves are not growing normally or as expected, you'll need to track down the causes and then alleviate the symptoms.

Leaf colour changes can be caused by changes in environmental conditions – such as a dramatic increase/decrease in temperature or widely fluctuating temperatures, underwatering or overwatering, excess sunlight – nutrient deficiencies, disease attacks, or even just old age!

Sometimes the whole leaf will change colour, sometimes only part of the leaf will be affected (such as the veins or the edges) or sometimes it will be distinct areas or blotches of a different colour. Check over the plant, looking carefully at the leaf – including underneath – and note the symptoms.


  1. If the whole leaf turns yellow, check the environmental conditions.
  2. If the leaf or part of the leaf is discoloured, check for nutrient deficiencies.
  3. If the leaf has distinct spots or a powdery covering, check for plant diseases.
  4. It the leaf has brown scorched edges, check for frost damage or potash deficiency.
  5. If the leaf is on a houseplant, it may not like the position it is growing in or the treatment you are giving it.
  6. If the leaf is at the bottom of the plant, it may well just be old age and the leaf is dying naturally. Even the oldest leaves of evergreens age and die.

Treatment And Control

Run through a few things in your head to see if the cause is logical. Check the plant for overwatering or underwatering, underfeeding or overfeeding, application of weedkiller close by, other plants showing similar symptoms, and ericaceous plants growing in limey/alkaline soil.

Above all, don’t despair! Some plants are short-lived and die as soon as they have flowered or just give up the ghost for no good reason. But growing your plants as well as possible – and using your green fingers – will help alleviate many of these problems.

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