As you peruse tomato varieties this season, the first question you should ask is “Are these determinate or indeterminate plants?” Each requires different planning.
Determinate (bush) varieties produce fruit on their growing tips, causing the branch to stop production once the fruit has set. They are most often used for container gardening or small spaces and generally do not need to be trellised. Popular examples are Roma, the Mountain series, and Cherry Gold.
Indeterminate plants produce fruit on side branches off a main vine, and are able to produce fruit all summer and fall until they are killed by the first frost. They can grow six to 12 feet tall and require staking or trellising. However, they generally taste better than determinate tomatoes because of the foliage-to-fruit ratio. Some of the most popular heirloom varieties are indeterminate types like Brandywine, Cherokee Purple, and Sweet 100.
Trellising keeps the foliage and fruits off the soil and increases air flow, reducing foliage diseases. An upright plant also makes it easier to spot pests. There is nothing more disappointing than a gorgeous tomato eaten up or rotting because it has been lying on the ground.
Gardeners must make trellising plans at planting or shortly after. Trellising a half-grown tomato is an impossible task without damaging the plant.
Basic tomato cages found at any big box store or garden center are the simplest, most popular, and most affordable method of trellising. However, these tend to topple over once the plant grows large, and they don’t fare well against Illinois winds. These are more effective with smaller determinate varieties, but are insufficient for indeterminate tomatoes.
A second method of trellising tomatoes is homemade wire cages; home gardeners construct these out of rolls of six-inch wire mesh, stacked and zip-tied double high to create an eight-foot tall column. The cages must be reinforced with at least one T-post, at least six foot tall, and set in the ground at least six inches deep. This is the method used by Bill Davison, local food system and small farms educator, because most of the work is done in the beginning of the season, but requires more upfront cost the first year.
A third method, the Florida weave or basket weave, creates a hedge of tomatoes. This method costs less than wire mesh trellising and uses fewer than half as many T-posts, but does require more labor throughout the growing season. Twine is woven between plants as they grow, then pruned back for height once they reach the height of the T-posts.
If you would like to learn more about tomato trellising and get hands-on training, University of Illinois Extension is hosting a tomato trellis demonstration project at the Sunnyside Community Garden in Bloomington at 9:30 a.m. June 7. We will post pictures of progress throughout the season at facebook.com/MidIllinoisMasterGardener. All are welcome to attend. Visit my blog Flowers, Fruits, and Frass for a more detailed how-to.