A Kratky tomato has no soil to anchor it, so a tall plant loaded with fruit can tip the container or snap its stem. Pruning keeps the plant a manageable size, and support keeps it upright. How much of each you need depends on the type of tomato.
Know Your Tomato's Growth Habit
| Type | How it grows | Pruning | Support |
|---|---|---|---|
| Micro and dwarf | Stays compact | Little or none | A small stake, or none |
| Determinate (bush), such as Roma | Grows to a set height, then fruits mostly at once | Light: remove suckers below the first flowers only | A cage or a stake |
| Indeterminate (vining), such as cherry and beefsteak | Keeps growing and fruiting all season | Regular: remove most suckers | A tall stake, trellis or overhead string |
Heavy pruning of a determinate tomato cuts its harvest, because its fruit forms on the side shoots.
Removing Suckers
A sucker is a side shoot that grows in the joint (leaf axil) between the main stem and a leaf branch. Left alone, each sucker becomes another stem with its own flowers and fruit, and an indeterminate tomato becomes a tangle.
- Find the sucker in the V between the stem and a leaf branch.
- Pinch it off while it is small, under a few inches, with clean fingers or snips.
- Keep one or two main stems on an indeterminate tomato.
- Remove yellowing lower leaves as the plant grows, so air moves around the base.
Rooted in water, a healthy sucker can grow into a new tomato plant.
Supports That Work Without Soil
- Overhead string. Tie a string to a hook or bar above the plant and loosely wind the main stem around it as it grows. This is how greenhouse growers support tall tomatoes, and it puts no weight on the container.
- A cage fixed to the container. Zip-tie or bolt a tomato cage to a sturdy tote's lid or handles.
- A stake beside the container. Drive a stake into the ground or a heavy pot next to the container and tie the stem to it.
- A wide, heavy base. A wide tote is harder to tip than a tall bucket. Set tall plants against a wall or fence.
Choose the container with support in mind: see Kratky tomato container size.
Back to the Kratky method for tomatoes.
Frequently Asked Questions
Should you prune Kratky tomatoes?
Prune indeterminate (vining) tomatoes regularly by removing suckers. Prune determinate tomatoes lightly, and micro or dwarf tomatoes hardly at all.
How do you support a tomato with no soil?
Use an overhead string the stem winds around, a cage fixed to the container, or a stake set beside the container. Don't rely on the net cup to hold a tall plant.
What is a tomato sucker?
A side shoot that grows in the joint between the main stem and a leaf branch. On vining tomatoes most growers pinch suckers off while they are small.