Master Gardener: Can or should I prune my tomato plants?

This question seems to come up a lot. The answer is, “Yes, you can; whether you should is up to you.”

The evidence is mixed about whether pruning tomatoes increases yield and whether it creates larger and better tomatoes. If your space is limited and you are growing indeterminate type tomatoes, you may decide to try tomato plant pruning to avoid overcrowding the plants. If you grow determinate types, you may be trying for larger and fewer tomatoes ripening at one time. You just need to make sure that you do it in a way that reduces the chances of disease but allows you to get the amount of fruit you want.

Here are some suggestions:

• Don’t start pruning plants until they get to be about 1-2 feet tall. Any smaller than this, and the plant may not recover from the shock of being pruned.

• Stake your tomatoes when you plant them to allow for a lot of heavy growth. Driving in stakes after they’ve grown large gives the plants an unneeded shock.

• Prune early to take out the tomato suckers. Where the branches meet the main stem there is an additional branch growing. This is the tomato sucker.

• Using a sharp, clean pair of pruning shears, snip these small sucker branches off. You can continue to prune out these extra branches for the rest of the season.

• Prune away any leaves touching the soil. You can also remove leaves on the interior of the plant to increase air flow and light. However, don’t prune too much. You want to leave branches that shade the fruit so that you avoid sunscald in July and August. By mid-September you can begin cutting back vines because any fruit that is setting might not ripen before frost.

• Prune in the early morning on a dry day. There is less chance of infection through the cuts.

• The best watering methods for pruned plants are soil-level (like using soaker hoses) rather than overhead watering which is more likely to invite the diseases that plague tomatoes.

For gardening questions contact the WSU Grant-Adams Master Gardeners at the WSU Grant County Extension office at 754-2011 ext. 4313 or Email ga.mgvolunteers@wsu.edu. Online reference services are available at https://extension.wsu.edu/grant. Sealed samples may be brought for identification Monday-Friday, 8-5 p.m. at the WSU Extension Office, 1525 E. Wheeler Road, Moses Lake.

For gardening questions contact the WSU Grant-Adams Master Gardeners at the WSU Grant County Extension office at 754-2011 ext. 4313 or Email ga.mgvolunteers@wsu.edu. Online reference services are available at https://extension.wsu.edu/grant. Sealed samples may be brought for identification Monday-Friday, 8-5 p.m. at the WSU Extension Office, 1525 E. Wheeler Road, Moses Lake.