Too much of a good thing destroys tomato crop


Help! My tomato plants have turned into compost junkies and I cannot get them off the good stuff.

Though the plants exist in a nice warm place against the house and are living in super rich soil, the blasted things don’t have any fruit. These plants truly are lushes, living off the nitrogen in the soil without any useful production.

The yearning for a fresh vine-ripened tomato starts in March for me. That’s when the seeds were carefully selected and planted. They were covered with plastic wrap until they sprouted on top of the fridge, where it is warm.

In late May I took four of the best plants and put them in compost-filled holes dug next to the west wall of my house. The remaining plants went to my son’s garden. He has little green tomatoes. I have none. Why?

My plants, grown so lovingly from seed for the past five months, look spectacular. They are almost a meter tall.

To find out why my plants look so healthy but have produced no fruit, I took a container filled with garden soil to Jim Hole of Hole’s Greenhouses and Gardens. A simple soil test takes about an hour and costs $20, which is redeemable at the greenhouse till if you buy plants or other merchandise in the store.

My problem, Hole said, was too much compost and therefore too much nitrogen. My garden soil is too rich for three types of plants: tomatoes, radishes and potatoes and rather than produce fruit, they produced leaves.

“It’s like you’ve given your tomatoes junk food and they keep re-reproducing leaves,” Hole said, adding that compost is desirable for growing most plants because it helps add nutrients to the soil at the same time as it loosens the soil and allows for more oxygen and water.

“By and large, we would suggest adding compost to your soil, but radishes, potatoes and tomatoes take the nitrogen and add more leaves. It’s as if the tomatoes say, “Conditions are great. We don’t need to produce fruit,” he said.

Hole also cautioned against using immature, unstable compost or manure. The compost or manure should be stable and should no longer be warm and actively decaying, or smelly.

“This week a lady brought in three samples of dying plants grown in manure-rich soil. When we tested it, we found the manure had an herbicide in it for killing weeds. The manure had not been composted. You have to watch where you get your compost from and find out what is in it,” he said.

Organic material should be worked into the soil.

“When you planted your tomatoes, you probably would have had good success if you had worked the compost into the soil instead of just putting it on top or in the hole when you planted,” he said.

It’s possible tomatoes grown in the same spot next year will do better, Hole added.

“Eventually the organic material gets used up and put into the air as carbon dioxide. Dig it in better and you should have a more dilute, even balance of compost and soil next year,” he said.

Susan Jones is a long-time local resident and reporter for the St. Albert Gazette.


About Author

Susan Jones has been a freelance writer for the St. Albert Gazette since 2009, following a 20-year career at the St. Albert Gazette. Susan writes about homes, gardens, community events and people.