Dear garden master,
I am growing tomatillos for the first time this year. The plants have been doing well but I recently noticed abnormal leaves: mainly that the new leaves are significantly more yellow, and there are some white drying spots on the older leaves.
The plants are about 3 feet tall and 2 feet wide. They are in a raised bed with full sun but experience a lot of rain recently.
Could you let me know what is the cause and how I should treat them? Thank you very much for your help and time.
Thank you for contacting Toronto Master Gardeners.
I have grown tomatillos, and can attest that they are not difficult to grow. Tomatillos need full sun, and soil that drains well. They are not cold tolerant. If you allow the fruits to mature and fall to the ground, they will likely grow in your garden next year.
Yellowing new plant leaves could be due to a number of factors: under or overwatering, too little or too much fertilizer, insufficient light, or temperature stress, pests and disease.
I suspect that either water or fertilizer factors are causing the yellowing leaves.
These plants prefer well-draining soil. You do not indicate the type of soil in your raised bed. Given the rain levels you mention, it is possible that the soil is not draining adequately. Adding organic matter to soil can improve drainage. In extreme cases of water tends to pool on the soil surface, you may need to replace the soil.
If planted in quality soil for vegetable growing, tomatillos should not need extra fertilizer. If you have fertilized your plants, stop fertilizing them. If you think the soil does not contain adequate nutrients, add compost and a fertilizer suitable for vegetables at a rate specified on the package.
I am not sure about the drying white spots. These could be evidence of some insect visiting. Inspect the leaves of your plants frequently, and pick off or hose off any leaf eating insects you see.
Tomatillos are subject to foliar diseases, especially in rainy and humid weather. While your plant symptoms do not suggest a disease, prevention is always a good idea.
To reduce disease risk, promote good air circulation in your garden. Space plants adequately, stake them and prune crowded branches. Also, avoid wetting the leaves when watering the plants. Mulching the plants will also help reduce the spread of disease.
Tomatillos are susceptible to the same diseases and disorders as tomatoes. Here is a link for more information on these:
I hope your tomatillo harvest is plentiful.