My potato plants were doing very well, then in the past week, one by one, plants are looking like they are wilting or in desperate need of water, yet potato plants right beside them are thriving. Within one week, half of my plants are, simply put, dead looking. No bugs noted on the leaves, they are being watered twice a week, and earth placed to mound the bases. any ideas? Thanks. (I live in Millbrook (90 min east of Toronto, with half a day of sun.)
It does sound like there is a possibility your potato plants are diseased. It is difficult to diagnose completely without a photo, but since you mention seeing no bugs on the leaves (assuming you’ve also checked the underside of the leaves), we will rule out potato psyllids.
Potato plants sometimes wilt due to extreme heat, under watering, and overwatering.
Given the description that the plants appear dead, it may be that you are seeing the result of Verticillium wilt. This is a fungal disease that begins in the root area and inhibits the transportation of water within the plant. You may notice premature yellowing of the leaves.
Verticillium wilt is a soil-borne disease that can persist in the soil for several years, so recommendations include:
- removing diseased plant material from the garden area to prevent its spread and either burning it or disposing of it completely (do not compost)
- crop rotation to prevent another occurrence of the disease in the following years
- growing potato varieties that are more resistant to wilt
The article below discusses potato wilt in detail.
Thank you for contacting the Toronto Master Gardeners.