Maintaining your Backyard Tomatoes

July is Tomato Month. Actually Bill 179, Tomato Act is a recent piece of Ontario legislation that declares July 15th as Tomato Day and the tomato the province’s official vegetable of Ontario (even though it is technically a fruit) for its substantial economic contribution.

Tomatoes are prolific and they grow fast in the heat and humidity of Ontario summers. That’s why tomatoes are one of the go-to plant choices for vegetable gardens. But to really maximize the potential yields of tomato plant, you need to do some minimizing. Simple maintenance will go a long way. Pruned and staked plants can produce larger fruit two or three weeks earlier than non-maintained plants.

In their first month of growth or so, all of the sugars produced by a tomato are used for more leaf growth which can double the plant size every 12 to 15 days according to agricultural experts. The more leaves, the more sugar produced, and eventually there is a surplus of sugar. This sends a signal that it’s time to produce tomatoes; but, if you have not maintained your tomato plant by this time, it might be so gangly and huge that production is stunted.

There are three simple rules to keep in mind when taking care of your tomato plants
1. Make sure tomato plants are off the ground.
2. Make sure tomato plants have enough room.
3. Don’t prune or stake tomato plants when they are wet

Tomatoes need to be supported and pruned so that each leaf is off the ground and has enough room to catch the sunlight. It’s best if tomatoes have one main stem so that the leaves have a chance of catching the sun’s rays. It might seem like cutting away big stems is taking away from the potential of your tomato plant, but less is more. If you let too many stems to keep growing, more of the sugar production from the leaves is put into new growth rather than the fruit.


Photo courtesy of Cheryl

Pruning your tomato is easy. One main stem with single branching stems growing from it is best. You can have more than one stem, but fewer stems result in larger fruits. Smaller stems, called suckers, can grow in the axils where the leave stems branch out of the main stem. These are called suckers because they suck the energy out of potential fruit production. Simply pick them off as soon as you see them. It is actually better to use your thumb than a knife or a pruner because the clean cut of a pruner can become more easily infected. If you let suckers get too big, you might need to use pruners. Large gaping wounds left behind will leave your tomato plant vulnerable to infection so its best to keep vigilant and put those suckers to rest.

Suckers take away from the strength of the main stem. The main stem is the backbone and lifeline of your plant. If a sucker is left to grow on its own, it will divert the sugars and nutrients away from any stems above it. Pruning suckers has wider benefits as well. Less shade on lower leaves means leaves dry faster and are less vulnerable to fungal disease.

There are three ways you can support your tomato: Cages, tomato fences/trellis, and stakes. The type of support you choose depends on the type of tomatoes you are growing of which there are two: indeterminate and determinate. Indeterminate tomatoes are the vining type of tomatoes and can keep growing until frost if they are properly taken care of. Determinate tomatoes, also known as the bush type, have been bred and selected overtime to grow more compactly and die after they produce the fruits.

Back to supports. Cages are good for determinate tomatoes which have a very predictable growing pattern. Indeterminate tomatoes, which are more prevalent are better supported by tomato fences/trellises and stakes. Cages don’t work well for indeterminate tomatoes because the plants will out grow them. Once they start growing, their weight will bend over the top of the cage and affect nutrient flow through the stem.

Tomatoes are the most popular backyard vegetable grown by far, and for good reason. To make that reason even better, take a few minutes to follow these simple tips. To learn more about how to select and prune specific varieties, make your own trellises/stakes/supports, and recipes for your homegrown tomatoes check out this Vegetable Gardener and Fine Gardening Pruning Tomatoes.

By Nate Van Beilen