Curling tomato leaves? Here's what your plant is telling you

Leaves rolling up and becoming brittle on stunted plants is a disorder called, aptly enough, tomato leaf roll.

Article content We independently select everything we recommend. Buying through us may earn us a commission, which supports our work. Q.

As in recent years, my tomato plants grew in fine health until early July, when the leaves on some of the plants begin curling up. In previous years, stunted growth followed. I cannot change the planting site for tomatoes from year to year.

On my property there is only one good growing space for them. Recommended Videos A. Leaves rolling up and becoming brittle on stunted plants is a disorder called, aptly enough, tomato leaf roll. It’s not a disease, but rather an affliction involving tomato variety choice, weather, and growing conditions.

You say that only some of the plants display symptoms. Check the variety or varieties of the affected plants and consider eliminating them from your roster of tomatoes next year. Varieties prone to leaf rolling are most likely to begin deteriorating in hot, dry weather, especially in stressful growing conditions.

The rolling can often be reduced by ensuring soil fertility as well as consistently even and adequate moisture levels. Mulching with a nourishing compost at the onset of hot weather, after a deep watering, is helpful. To retain moisture further, add a layer of dried leaves or/and chopped straw.

Try to renew the soil as much as possible each spring by removing some of the old and adding compost, fresh soil, or/and planting mix. Q. I’ve heard and read varying opinions on using wood ashes in the garden. I’d appreciate knowing yours.

A. I advise caution in using wood ashes. They are calcium-rich and highly alkaline. One of my friends turned her beautiful blue (preferring an acidic soil) hydrangea into a producer of muddy pink flowers by emptying a bucket of wood ashes around the bush.

Still, where a reduction in soil acidity is appropriate, wood ashes used in moderation can be useful. Wood ashes are also fairly high in potassium, which in excess can cause stunting in plants by overpowering a soil’s nitrogen, which promotes green growth.