Tomato Patch: Pinch That Sucker?

Sucker is a point of arrow
Leaf stem is to left of sucker
Main stem is to right of sucker

I am a sometimes sucker pincher. Sometimes I pinch them. Sometimes I don’t. Every year I vow to pinch them, but usually I pinch them early in the season and forget about weekly followup.

You’re reading something that indicates Tomato Patch in the headline, so you know suckers must have something to do with tomato plants. But just what are they?

Here’s how the chapter on vegetables in the University of Maryland Master Gardener Handbook defines them and why you may want to pinch them: “Suckers are shoots that arise from axils (the angle where a plant stem and leaf branch meet). These shoots will eventually produce flowers and fruit. However, moderate pruning will increase fruit size, hasten ripening, and keep your plants more manageable. Prune staked tomatoes to one to three main stems (plant spacing can be reduced in these situations). Remove all other suckers weekly. It is especially important to remove suckers that emerge from the plant base. Pinch shoots off with your fingers.”

Brandywine Red plant before pruning

Johnny’s Selected Seeds gives similar, but slightly different, advice on its website: “Prune your indeterminate tomatoes (but not determinate varieties). Prune to one or two main branches or "leaders" which will ideally be about the same size. This is accomplished by removing side shoots or "suckers" that grow in the leaf axils between leaves and the stem. If you want two leaders, which is often recommended in case the main stem is damaged, leave one sucker directly below the first flower cluster. Prune all other suckers that grow on both stems. After that, prune off all new suckers. The suckers should be snapped off when they are no larger than 2-3" long. Larger suckers may need to be cut off with pruners. Pruning should be done about every week to 10 days to stay ahead of sucker development.”

If you read 10 articles on suckers, you probably will get basically similar information but differing details. Here are several differences and my take:

Suckering is important on indeterminate tomato varieties—the “tall” plants that continue growing until frost kills them. By definition, determinate, or “short,” varieties are limited in their growth, have few suckers, and will not leave you groping for sunlight in an overgrown jungle of tomato leaves.

Brandywine Red plant after pruning

Pinch the suckers when they’re young and tender. Just snap them off with your fingers. The “wounds” will heal quickly. However, the stems of suckers become tougher as they age and may not come off as cleanly with your pinch. That’s when you may need to use your pruners or scissors, though some sources say such tools may introduce pathogens to cut tissue.

Some sources emphasize pinching of lower suckers because they usually are shaded by higher leaves and usually produce little fruit. Another reason is that leaves closer to the ground are at higher risk of diseases that are endemic in local soils that can splash onto lower stems during rain or watering if plants aren’t well mulched.

How many suckers should you pinch from each plant? Intensive growing systems, such as Mel Bartholomew’s “Square Foot Gardening,” recommend that you remove all suckers. For general gardening situations, the consensus seems to be to let one or two suckers grow, so each becomes a leader with leaves, flowers, and fruit of its own.

This year I’ve vowed once again to pinch suckers weekly. I started Friday, perhaps two weeks behind schedule. Some of the suckers already were a foot long, and when I pinched them, sometimes they pulled small strips of tissue from the main stems. That’s a good reason and also a reminder to pinch suckers when they are young and tender.

Photo 1 shows a sucker growing in the axil where tomato stem and leaf join. Photo 2 shows one of my Brandywine Red plants before I pinched suckers. Photo 3 shows the same Brandywine Red after I removed all the extra growth. The difference is remarkable—sort of like when I get a haircut after four or five weeks.

Since I was doing “catch-up pinching,” it took nearly an hour and I carried an armload of pinched suckers from my Tomato Patch. But if I pinch regularly, future maintenance will be both quick and minimal.

Should you pinch your suckers? I like the way John Page puts it in the little booklet “Grow the Best Tomatoes” (Storey Publishing): “Prune them if you are a sucker-pruner. Pinch them if you are a sucker-pincher. Let them go and things will get pretty dense and green, often requiring some topping.”

Here are two short videos that will show you how to pinch suckers. To watch Jon Traunfeld of the University of Maryland Extension in “Pruning Tomato Suckers” (3:17 minutes), CLICK HERE.
To watch Johnny’s Selected Seed video, “How to Prune Tomatoes (2:52 minutes), CLICK HERE.