Most people are better at weeding and watering than they are at pruning. It can be confusing, for sure, but this post should clear things up for you. Beefsteak tomato plants are “indeterminate,” which means they require staking and pruning to grow properly. By contrast, many cherry and grape tomato plants are determinate and grow shorter, more like bushes, and do not require staking and pruning.
You’ll need to stake your plants once they look like they’re starting to bend toward the ground. And keep a close eye on them… tomato plants can grow really quickly. I use fairly heavy-duty 2×2″ stakes, sharpened at one end. Hammer them into the ground fairly close to the main stem. First, try to lean the tomato plant on the stake in a way that it’s standing up or leaning on it without being tied. Then use pieces of soft material to secure the plant to the steak in 2 or 3 places along the main stem. Don’t use wire or anything that will cut into the stem. I use soft twine or old socks or T-shirts torn into strips. Also, consider where on the plant you’re tying. Left unattended, a plant can grow quite a bit in just a few days and a misplaced tie can snap off a good branch as the plant grows. And don’t tie the stem tight to the stake, leave some room for it to expand and grow upward.
Now that your plant has started to grow, clip off all the suckers, stems and leaves below the first branch that has flower/fruit clusters. Keeping leaves off the ground will discourage disease and pests.
Check your plant every few days. When you see suckers growing out of the crevices between the main stem and leaf-bearing branches, pinch them off. Use clippers if they’re too thick to pinch with your fingers.
Never prune your tomato plants after it rains or while they’re still wet from watering. Humidity and water droplets can allow fungal spores and disease remnants to enter through the open plant wounds.
The tomato plant will continually try to grow new main stems out of the crevices between the existing stem and leaf-bearing branches. If you let them grow you’ll soon find that you need multiple stakes to keep the plant growing upward, and you’ll have a near-unmanageable mess on your hands. Keep a close eye on your garden and try to prune your tomato plants every few days. Leaving them for too long will make it difficult to know which stem is the true main stem and which needs to be pruned away. We maintain a plot at a community garden a few blocks from our house and I’ve learned the hard way that a week of neglect can be difficult to come back from.
Getting bigger tomatoes
Once the clusters of tomatoes start to grow, pinch off some of the smaller duds. Meaning, if you’ve got a cluster with 5 tomatoes growing, pinch off the 2 smallest ones, or the two that look the least promising. This will help the remaining fruit to grow bigger and faster. The same applies for diseased fruit or tomatoes that have been attacked by pests – pinch them off. Why waste your water and sunlight resources on fruit you’re never going to eat.
If you maintain your beefsteak tomato plants by adjusting the stake ties and pruning off new attempted main stem suckers, along with regular watering, weeding and fertilizing, they should grow to be 5 or 6 feet tall and produce some fairly large fruit.