Wilting tomatoes and cukes

(Question)

Good day!

My name is Marcela and I am looking for a place that will test my garden soil. Cole’s Notes – last year my tomatoes and cucumbers were horribly effected by “something” in the soil (that’s my guess) that caused them to grow, but wilt, produce fruit but at a much smaller size and the yield was not nearly as it should have been. My garden is a good size and none of the other vegetables were affected; sweet peppers, hot peppers, zucchini, broccoli, garlic, potatoes. The other thing is this; I had the same problem the year before, again only with the tomatoes and cukes, but to a far lesser degree. Whatever is happening seems to have “spread” to the entire garden, and still only affecting said plants.

I don’t know if y’all usually assist with this sort of thing, but I thought I’d give it a shot. I would greatly appreciate any help you could offer! I want to fix the problem before planting this year. PLEASE HELP!!!!!! Where can I send my soil to be tested?

(Answer)

Thank-you for contacting Toronto Master Gardeners with your question.

Lacking the ability to observe your plant symptoms, it is difficult to determine exactly what is causing them to wilt and become unproductive. Environmental conditions such as drought or water-logging can cause plants to wilt, as can nutritional deficiencies or imbalances, but it is unlikely that these common problems would affect only your cucumbers and tomatoes 2 years in a row. Tomatoes and cucumbers are susceptible to many diseases, though again, few diseases attack both types of plant while leaving other related vegetables untouched, as you have been experiencing.

The most common wilt diseases of tomato are fusarium wilt, caused by a fungal pathogen, Fusarium oxysporum, and verticillium wilt, caused by the fungal pathogen, Verticillium dahliae. Both diseases cause wilting from the bottom upwards in the plants. They are not treatable. The pathogens overwinter in the soil and attack the plants through the roots and stems. Cucumbers are often victims of bacterial wilt, caused by Erwinia tracheiphila. This bacterial disease is spread by cucumber beetles. Some sources I reviewed indicate that cucumbers can also fall victim to fusarium wilt. Since you have not mentioned cucumber beetles and both your tomatoes and cucumbers are affected, this seems the most likely culprit.

It is great that you are making your inquiry now, prior to planting time, because the most effective way to avoid these wilts is to plant disease resistant varieties. Cornell University provides a list of disease resistant vegetables:

https://www.vegetables.cornell.edu/pest-management/disease-factsheets/disease-resistant-vegetable-varieties/

When you are sourcing seeds or reviewing varieties of plants, be sure to check for the codes which indicate disease resistance.

Having your soil tested is always a useful exercise when preparing a vegetable garden. OMAFRA ( Ministry of Agriculture, Food and Rural Affairs ) has a list of accredited soil testing Laboratories in Ontario which can be found here

The University of Guelph Laboratory Services will also preform soil analysis. While some soil testing facilities provide only a breakdown of soil pH and mineral nutrient content, the Guelph Lab also tests for bacteria and other soil pathogens. This could be especially relevant in your situation. The services provided are listed here:

https://afl.uoguelph.ca/soil-testing-services

This link gives step by step instructions on how to submit samples to the Guelph lab.

Because COVID restrictions may be having an impact on these services, it is best to contact them before sending in samples.

I hope you have better success with your cucumbers and tomatoes this season!