John planted six cherry tomatoes way too close together last year. By mid-July, he ended up with an impenetrable jungle of green vines that produced exactly zero edible tomatoes before a nasty wave of blight took the whole mess out.
Turns out the fix is stupid simple. Five minutes of aggressive cutting early in the season completely changes how the plant behaves and focuses its energy on the fruit.
Here’s the pruning method that works every time for us.
Know What You’re Growing First
Before you grab the scissors, you have to know what kind of tomato you planted. This is the biggest mistake people make.
Determinate tomatoes are bush types that grow to a set height, produce all their fruit at once, and then die. If you prune these heavily, you are literally cutting away your harvest. Leave them alone.
Indeterminate tomatoes are vining types that will grow until frost kills them. These are the ones that turn into uncontrollable monsters. You absolutely must prune indeterminate varieties if you want a decent yield. Honestly, the cheap plastic plant tags from the nursery usually tell you which type you have right on the back.
Hunting Down the Suckers
The first thing you need to target is the suckers. These are the sneaky little shoots that pop up in the “V” joint between the main stem and a mature branch.
- Wait until the sucker is about two inches long.
- Your thumb and index finger are the best tools for this.
- Snap the shoot cleanly to the side until it breaks.
- Thick stems larger than a pencil require sharp bypass pruners so you don’t tear the main vine.
I tested this aggressive pinching method on my balcony tomatoes last summer and the difference in fruit size was obvious within a week. When you remove that extra foliage, the plant stops wasting energy growing leaves and redirects it into making bigger tomatoes. (Trust me, I learned the hard way that letting them grow wild gets you nothing). Not complicated.
The Single Stem vs. Two-Stem Debate
Once you start pinching suckers, you have to decide how many main vines you want to keep. Most commercial greenhouse growers are completely ruthless. They train the plant to one single, massive main stem and violently cut off every single side shoot that appears.
We usually prefer a two-stem approach for our backyard raised beds.
We let the main stem grow, and we allow the very first strong sucker that appears just below the first cluster of flowers to develop into a second main stem. We then prune both of those stems aggressively as they grow upward. This gives you a slightly larger harvest per plant without sacrificing the airflow that prevents disease.
Once you’ve got the suckers under control, the rest is mostly about airflow.
Stripping the Bottom Leaves to Beat Blight
Tomatoes are incredibly susceptible to soil-borne fungal diseases, especially early blight. When it rains heavily, or when you water carelessly, fungal spores in the dirt splash up onto the lowest leaves. Once the fungus gets a foothold, it climbs up the plant and destroys everything.
To stop this, we strip off all the leaves on the bottom ten to twelve inches of the main stem.
Don’t do this immediately after planting. Wait until the plant is at least three feet tall and well-established. Just snap the bottom branches cleanly off at the base. You want bare stem from the dirt all the way up to that first foot mark. If you’re struggling to keep things tidy, this is also the perfect time to review how to grow zucchini vertically like a tomato to save even more ground space.
Supporting the Stems as They Grow
Pruning is useless if the plant just flops over onto the dirt. Because you are forcing the tomato to grow tall rather than wide, it needs serious structural support.
Don’t bother with those flimsy wire tomato cages they sell at hardware stores. They bend and collapse by August. Instead, pound a six-foot wooden stake deep into the ground right next to the root ball. As the main stem grows taller, tie it to the stake every twelve inches using soft garden twine or strips of an old cotton t-shirt. Tie it loosely in a figure-eight pattern so the stem has room to expand as it thickens.
Topping the Plant in Late Summer
This is the one pruning step almost everyone skips, and it costs them dozens of ripe tomatoes at the end of the year.
About thirty to forty days before your first expected autumn frost, your tomato plant is still going to be pushing out new flowers. Those new flowers will never have time to turn into ripe tomatoes before the cold kills them.
Take your shears and cut off the very top growing tip of every main stem.
This signals the plant to stop growing taller. All its remaining energy gets shoved directly into ripening the green fruit that is already hanging on the vine. If you want to pull a brag-worthy pile of tomatoes right before the season ends, this cut is non-negotiable. Worth the effort.
Dealing with Diseased Leaves
Even with perfect airflow, you’ll probably still see some yellowing or spotted leaves as the season drags on. Don’t leave them hanging there.
Grab a pair of clean shears and snip off any leaf that looks sick. Bag those leaves up and throw them in the regular garbage. Do not put them in your compost pile, or you’ll just spread the fungal spores to next year’s garden. (Yes, even in the middle of a hot summer, spores survive). I wipe my pruner blades with rubbing alcohol after every single cut when dealing with sick plants. It feels tedious, but it stops the spread instantly. Same idea as weeding. If you’re dealing with tight quarters, check out our guide on growing juicy tomatoes in small spaces for more tips on managing airflow.
Frequently Asked Questions
1. Should I use scissors or my fingers?
Honestly, I’d skip the fancy snips and just use your thumbs for the small stuff. Pinching young suckers by hand is faster and actually helps seal the wound quicker. Only reach for the bypass pruners when a branch is thicker than a pencil and won’t snap off cleanly.
2. What if I accidentally cut the main stem?
Don’t panic. If you accidentally snip the main leader, the plant isn’t dead. It will simply force a new sucker to become the new main stem. Your harvest might be delayed by a week or two while it recovers, but the plant will absolutely bounce back.
3. Can I plant the suckers I cut off?
Yes, and you should. If you let a sucker grow to about six inches long before you snap it off, you can stick it directly into a glass of water. In about a week, it will push out a dense network of white roots. You can plant that rooted cutting in the dirt for a free, brand-new tomato plant.
Your Tomatoes Just Need a Little Attention
Pruning feels intimidating the first time you do it, mostly because it feels wrong to cut pieces off a healthy plant. But once you see how much bigger and faster your tomatoes grow, you’ll never go back to the untamed jungle method. Give it a season. You’ll wonder why you didn’t start sooner.