The leaves on my callalloo are changing. I am in Mississauga, Ontario. They seem to be dying from the edge. Sometimes they have similar spots in the middle of the leaves. They are planted in full sun in the same position I plant them every year. Can you tell me what is causing the problem and how to correct it please?
Thank you for contacting the Toronto Master Gardeners about the leaves on your callaloo (Amaranthus spp.). Assuming that your callaloo appears to be otherwise healthy, I think what has affected the leaves is leaf scorch, which we have seen quite a bit of this summer.
From a response to a previous question sent to the Toronto Master Gardeners :
‘Prolonged high temperatures, hot and drying winds, and low rainfall are the most common reasons for leaf scorch. With these weather conditions, large amounts of water evaporate from the leaf surfaces, and the plant roots are unable to provide enough water quickly enough to replace what has been lost by this transpiration. Leaf tissue dies as a result. Typically, leaf scorch appears in July and August, first on the side or sides of the plant most exposed to sunlight and prevailing winds. Plants may lose some leaves as a result of leaf scorch, and it can weaken the plant, making it more susceptible to insect infestation and disease, but leaf scorch alone won’t kill a plant.’
Callaloo does best in moist, average and well-drained soil, in full sun. It is a low maintenance plant, but it does need watering in times of severe drought (which we did experience this summer). However, it could develop root rot in poorly drained soil. It also appreciates some shade in hot summer climates, which I would say we don’t typically have, but did at times this summer.
In addition to extra watering during hot, windy, droughty weather, I also suggest that you put a few inches of organic mulch around your callaloo (a few inches away from the base) to conserve soil moisture and reduce watering frequency.