I'll try to be brief. I know I won't. Apologies in advance. I was going to wait to discuss this but I think these early results are worth reporting for some seeking a fall crop. I may not even need to update. I'm almost certain to conduct a similar but expanded experiment next year because of the observations so far. I'm aware the sample size renders results anecdotal. I understand some of the most experienced and successful growers here do not prune and can be good natured but condescending in response. I'm sure its been discussed in detail here, but recently it's been brief anti-pruning comments without explanation. I'm new here and I know what's fresh to me might be stale to others. Maybe a fresh conversation will be helpful. Maybe my experience will encourage some to prune in certain situations. I intend to.

I have to add some background, sorry. For years I grew 6 to 10 tomato plants in big clay pots tied to a 12 foot south facing trellis in a perfect climate. It was easy. I moved to the desert where growing tomatoes is discouraging. I have a friend of nearly 30 years who has made a living growing primarily greenhouse tomatoes. He prunes every plant to one or two stems. He also plants about an acre to some determinate hybrid that isn't pruned, and he has 600' of 6' fence planted to an indeterminate cherry pruned to three stems on the bottom then left to grow out. I never pruned anything in the past except the old parts late in the season.

I mention the friend because I never considered his indoor operation to have anything to do with growing outdoors. They are apples and oranges. We've almost never discussed growing tomatoes. Our time together is limited to pick up basketball and we're getting old. But after the 08 growing disaster, I started reading, and it seems to me that the internet is full of instructions advising outdoor tomato growers to use indoor pruning techniques. In general, I think this is a mistake -- one I intend to keep making for reasons explained below.

18 plants were put into the experiment. From seed I grew a packet each Better Boy and SS100. I chose 8 of each and planted them together on the south side of my house where they would get nearly identical light, water, and fertilizer. I then began pruning two of each to two stems, four stems, or six stems and leaving two alone. One stem seemed ridiculous but maybe I'll try it next year.

The other two plants were Goliath hybrids purchased at Home Depot. One is trimmed to three stems the other is not pruned. In this case, the three stem plant may be the better plant pruned or not. It's way ahead of the unpruned plant. It has 15 fruit set. It has clusters of blossoms on each vine looking to set more. It is a little light in foliage, and I may need to protect the fruit with homemade mini-shades, but it set 6 fruit before the other set one. Since the unpruned plant set one almost a month ago, it has set just two more and that was last week. The pruned plant's lowest fruit is three times the size of anything on the unpruned plant, and it will be eaten two to three weeks earlier. The rest of the fruit on that plant (14 tomatoes) is ahead of all but the first lonely fruit on the other plant. Pruning wins this battle in a first round knockout. I guess it's possible the unpruned plant could rally and end up with a more impressive yield. It does have more blooms this morning, and is seemingly a healthy plant, but I am very doubtful considering the coming summer heatwave.


I've read several times that pruning can decrease disease by allowing air flow. The only plant I'm losing to disease is an SS100 pruned to two stems. Perhaps the constant amputations weakened him making him susceptible to Fusarium the others have resisted. It was also the first to set and ripen fruit, but only by a few days. It has three large trusses ripening, several others starting to set fruit, and I'm going to pull it soon. The other two stem SS100 was the second earliest plant and I am eating off of it daily. The four stem plants are next and a little ahead of the six stem and unpruned plants. But not by much. And btw, trying to keep a vigorous plant like this to six stems is an exercise in futility. I've let those plants grow as they wish as of two weeks ago. They are all loaded up and soon to deliver impressively. While the two stem plants are earlier, cherries are all pretty early and the price of pruning is too steep here. When the senility is kicking in, and I'm puttering around out there chatting with my plants, I apologize to the two and four stem SS100s. It was abusive. They do not look right at all. I think they're embarrassed, naked, and mocked by the bigger relatives. One is dying. They are a little stunted from the abuse and will not produce nearly as much fruit in the end. I'm not cutting on any of them any more. Also as I understand it, sugar comes from foliage. Well, these two stem cherries I have been eating have not been as sweet and tasty as I remember, but one little red dangler on a four stem plant was scrumptious, far superior. Just another observation against pruning cherries.

The Better Boys are similar to Goliath. The two stemmers were a full month ahead of the unpruned plants in setting fruit. From the two two stem plants I have harvested three and have another 8 coming in likely sometime this weekend. The four stem plants are clearly next and they are loaded with fruit, some full sized but green. I'm impressed with how bushy a two stem Better Boy can be. Unlike Goliath the fruit seem well protected from too much direct sun. However, also unlike Goliath there is a better set on the unpruned and six stem plants. I'm eating off the two stem plants first, the four stem plants next, and we'll see how this impressive but still very immature fruit set develops a month behind on the rest.

To summarize with premature conclusions based on one season with strange weather (a 3 week May heatwave causing blossom drop followed by three weeks of tomato bliss). In short seasons, like here in the desert, where long season plants are difficult to see through to fruition, pruning seems to bring the fruit on much earlier (although conditions specific to 09 could be part of this), not a little earlier, but a full month earlier in my case, and that could be the difference in actually munching on perfect Brandywines or Cherokee Purples and being frustrated. If you're impatient **cough containerted cough** for the fruit to ripen, pruning a few here and there will get you a few sooner and might stop you from berating those poor slowpoke plants of yours. If I was back on my sunny hill near the coast, I doubt I would ever prune a tomato plant. Hmmm, I'd have to think about given these results though. I enjoy the rapid landscape transforming growth and deep green foliage more than chopping off healthy suckers. I believe in most reasonable conditions more fruit will be produced on plants left to their own devices in supportive cages.

The Mojave Desert isn't reasonable though, and pruning may serve some surprising purposes. I say surprising because I've read several times that the foliage cover is so crucial out here that you must not prune. Well, I did, and I'm pleased with some of the results.

Another plus for pruning is space. While I spaced everything evenly, it's obvious I could have fit in a few more pruned plants in the space allotted for the two stem plants. Four Cherokee Purples will replace the dying SS100. Fascinated by the wide variety of heirlooms available, I may just grow 20 (greenhouse style) where I would normally grow 6 or 7 hoping an early set brings success like this year, and I get to experience more variety. I won't do that to vigorous cherry plants. I think the benefits may be real with larger fruit though.

I am growing a fall crop of 50 Cherokee Purples and continuing the pruning experiment with them should they somehow survive July and August out here. Fingers crossed for that.