CORVALLIS, Ore. – Giving tomato plants a boost can make a difference in the amount of fruit the plant produces, according to Master Gardeners trained by the Oregon State University Extension Service.
"If tomatoes lie on the ground, they can rot," said Master Gardener Bob Woods. "Animals can attack them and disease can ruin the plants. Most tomato plant diseases come from the soil. It's important to use a support structure to keep the leaves and fruit off the ground."
You can buy a tomato cage at garden centers – but they can be costly or flimsy. Or plan ahead to build your own creative and durable support structures out of rolls of mesh, available at most home improvement stores.
Master Gardeners Bob Woods, Sherry Sheng and Sherry Holley teach two workshops through the Extension Service every spring in Clackamas County: "Secrets of the Tomato Masters," open to the general public, and "Tomato Cage Workshop," open only to Master Gardeners – where participants build their own support structures out of concrete reinforcing mesh. Find next year's dates at the OSU Extension Clackamas County Master Gardeners website.
"Gardeners I know have used concrete reinforcing wire for decades," Sheng said. "At the end of the season you can stack three or four together and roll them up for storage. It's a long-lasting solution."
The idea for the workshop came about when the trio of Master Gardeners drew inspiration from a garden by Bob Woods in Oregon City. Woods, 80, a tomato aficionado, grew 82 tomato plants in 2013 – "one for every year of my 80 years and two extra that I couldn't part with," he said.
Early in the season, brainstorm about if you want tomatoes for salads, sandwiches, sauce or canning, then choose varieties by reading seed catalogues or asking local Master Gardeners for suggestions.
Once you have a list of varieties, learn whether they are determinate or indeterminate by reading labels, advised Sheng. This will help you choose an appropriately sized structure. A determinate variety is bred to grow to a compact height of about 3 feet and fruit ripens within a couple of weeks late July to early August. A two-inch by two-inch wooden stake is sufficient to support each main stem of the plant. Old nylon stockings or strips of fabric are ideal ties.
On the other hand, indeterminate or "vining" tomatoes grow about 6-10 feet tall and produce fruit throughout the growing season. They need more room and stronger support to flourish.
For indeterminate tomato varieties, here are some helpful steps to building your own support structure.
- Buy a roll of concrete reinforcing mesh consisting of stiff 9- or 10- gauge wire at a garden center. Get a roll that is about 150 feet wide by 5 feet tall, which costs on average about $100-150. Using 5-foot sections for each cage, a roll can yield 30 cages. The mesh can be used to support other vining plants and for fencing.
- Use a bolt cutter to slice the mesh into the dimensions you want. You will want a panel with a row of straight vertical wire on one end and a set of sharp prongs on the other.
- A 5-foot panel will form an 18-inch diameter cage. A 6-foot panel will form a cage of 23-inch diameter. Cut a longer panel for larger cages.
- With pliers, bend the prongs at 90-degree angles to form hooks. Link the hooks to the straight vertical wires to form a cage.
- Cut and remove horizontal wires, which leaves 6-inch spikes for legs.
Finish these do-it-yourself structures by April before you begin planting. The wire will rust but should survive for years. Prune tomato plants in July and August.