Depending upon who you ask (and they’ll often tell you that it further depends upon what variety you are growing and how you are supporting them) tomatoes either don’t need or do need pruning.
Let’s get down to what I think works according to the general consensus of whatever science there is.
- Pruning will reduce your total fruit yield, but what is yielded will be larger.
- Pruning is not required, but it in many cases and in many zones will improve the plant’s odds of avoiding fungus invasions and other disease. Overcrowded plants can create little humidor environments with moist air stuck inside and limited air circulation! Keep in mind that removing too many suckers etc. can actually hurt your fruit. The leaves create little sun umbrellas that help eliminate sunscald. The more sun and heat that your zone gets, the better it is to leave more leaves.
- Focus your real pruning on your indeterminate tomatoes. Smaller determinate (bush) tomatoes will have their burst yields reduced if you prune them. From time to time, I prune away smaller lower branches or suckers from determinate plants like Roma, but it’s just to keep things off of the soil. For semi determinate varieties like Celebrity, prune just a little – wait for flowers to emerge and prune off the suckers (we’ll define that in a second) below the first flower cluster, but not the sucker just below it – skip one in other words.
- Wait until the plants have settled nicely and have grown a bit. For my bigger indeterminates I’ll wait until the first few suckers (seriously.. we’re going to define that in a second) have developed into branches/vines and my plant is filling in the cage or the stake.
- I’m gonna get you sucka! Prune the suckers. Okay, so moving on… Alright, alright. The definition of suckers. You’ll see it defined something like – “the little shoots that form in the crotch (yes.. crotch) of a branch and main stem”. Run your finger up a tomato plant, starting at the base of the stem – the main vine. You’ll hit a branch soon. Look right where the main vine and branch join and you may see a sucker – a new branch shooting up at about a 45 degree angle. Left to its own devices, it will soon turn into another vine and will even grow fruit. Leave a few on to grow and “pinch” off the others. That’s pruning.
Experimentation is probably the key here. Some people swear by pruning others swear while pruning (like me.. man that’s a lot bending over) and others swear that pruning is a waste of time. See what works for you. Do it all the way! Do it half way (a little thing called “missouri” pruning where you only pinch off the tip of the sucker), but do something for goodness sake!