To prune or not to prune suckers on tomatoes – the age old debate continues – until now!
There are two distinct camps here. Some people prune suckers on tomatoes so that they end up with a single stem and they claim that is best. Others don’t prune suckers at all and they claim their method is best. And then there are the ones that sit on fence and sucker to two or three stems. In this blog I’ll tell you the best way to prune tomatoes.
What are Tomato Suckers?
Suckers are the side branches that form at the point leaves join the main stem. If left on the plant, they will become secondary stems and start making fruit. This is mostly an issue with indeterminate tomatoes since they just keep growing taller and make more and more stems. In longer seasons they can make huge plants.
Suckers do not need to be removed. A tomato plant will grow and produce well if you leave all the suckers on the plant, but there are some reasons why you might want to remove all or some of them.
Now that I have described suckers, I have to tell you that everything I just told you is wrong. A sucker is actually a new growth originating from roots, below ground. So clearly a tomato sucker is not a true sucker. But for some reason everybody calls it that, so I’ll continue the tradition in this post.
Different Ways to Grow Tomatoes
There are three basic ways to grow tomatoes.
- Simply plant and let nature do its own thing. They will form side branches and tend to sprawl along the ground.
- The second option is to let it do its own thing but keep it maintained inside a wire cage. This keeps the fruit off the ground and makes them easier to pick.
- The third option is to prune the plants to a single main stem and tie that to a stake.
Each of these methods offers some advantages as shown in the following table.
Suckering will reduce the overall production (i.e., total weight of fruit) of a single plant. On the other hand, more energy is put into fewer fruits, resulting in larger fruits. The other benefit of suckering is that tomatoes mature earlier, and this can be a big help when growing in colder climates.
Suckering Increases Productivity
The above statement about productivity is only true for a single plant. Plants pruned to single canes can be planted closer together so that there are more plants per square yard. If you measure productivity on an area basis and you plant closer together, productivity is about the same for suckered and unsuckered plants.
Suckering Can Reduce Diseases
The disease potential is higher for unsuckered plants since their leaves tend to be crowded. This reduces air circulation and makes it easy for diseases to spread. The single-stem method also keeps leaves off the ground, making it harder for pests like slugs to find the plants.
Un-suckered plants are less likely to have problems with BER (blossom end rot) and cracking, but this can usually be prevented in the single-stem method with proper watering.
Other Ways to Grow Tomatoes
So far I have described three methods for growing tomatoes, but of course you can use hybrids of these. With both the cage and stake method, you can leave the first couple of suckers to make side branches and then prune all of the remaining suckers. In climates with longer seasons, you can also take off the early suckers, root them and then plant them to increase the number of plants.
Hybrid methods produce hybrid results.
Best Way to Grow Tomatoes
- In short season climates, the most valuable goal is early fruit, so grow them as pruned single stems. This is also a good method in disease-prone areas. Remove suckers by hand, with a quick snap, before they are three inches long. Prune on a sunny, dry day so the wound dries quickly.
- Pruning suckers will result in larger fruit, which, for the homeowner may be more desirable than overall productivity.
- The cage method, with some suckering later in the season, works well for many growers.
- The issue of suckering is less important than selecting the right variety and watering properly.
- Do not remove suckers on determinate tomatoes.
- Fertilize tomatoes correctly for best results.
More Posts About Tomatoes
What Causes Blossom Drop in Tomatoes
Growing Tomatoes – Should You Remove Bottom Leaves
In the southern California climate, single staking leads to sun burned tomatoes and unless heavily mulched, quicker drying out of the plant.
I grew tomatoes in containers this summer and one of my tomato plants in the biggest container grew huge but produced no flowers and no fruit! What happened and what caused it?
The plant is extremely healthy looking and was planted in the same soil as my other container tomatoes (A combination of native backyard soil and compost.
Could be too much nitrogen.
I use the suckers from my heirloom tomatoes as cuttings. They are placed in water until roots appear. Then, they are placed in soil in cup for further root development. These steps take about 3 weeks. Then, they are planted in the garden. I have found they serve as insurance against losing the “parent” plant because of disease or predation from gophers. I have also gifted these clone/cuttings to other gardens to add variety to their crop and introduce a gardening idea of cuttings.
I don’t bother pruning suckers, but I cut off a couple of the lowest branches so all foliage is off the ground. i get NO slugs this way. I have noticed I seem to get fewer diseases this way, too.
It’s hard for me to picture growing indeterminate tomatoes with a single stem. In my garden I would need a fairly large step ladder to pick them. I’ve read that commercially grown Green House tomatoes are grown this way. They appear to use a method that as the plant grows and the tomatoes get higher, they pull the vines down and wrap them in a circle at the bottom. It would be quite interesting to see how they accomplish this. It may have use for gardeners.
This is a timely read. My tomatoes are staked and this year not pruned early on because of busyness of the season Later, I pruned a bit because of such heavy leaf growth. My results match your chart exactly. The determinate Winter Keeper variety are big, bushy and producing lots just as they should. Thanks for your encapsulation of this process.
Thanks – makes perfect sense. By the way, your fourth heading reads ‘Sucking Increases Productivity’!
Thanks for the correction.
I had a closer look at your bullet points and don’t agree with several points.
1) cause a dependency – not really. Farmers always have the option to use organic fertilizer, but a) there is not enough for all the crops we try to grow, and b) they are not cost effective. This is not a dependency – just good business. Farmers can stop using fertilizer any time they want.
2) Both types of fertilizer cause runoff and pollution – it is the amount added that is the real problem. Excess manure is just as bad as excess synthetic fertilizer.
3) Application of synthetic fertilizer does not deplete organic matter. Cultivation does. Applying too much nitrogen can increase microbial action which uses up organic matter, but it also creates organic matter.
4) “Harmful synthetic fertilizers damage human vascular and respiratory systems” – since both forms of fertilizer release the same nutrient ions – both will also cause this problem. This problem is mostly due to the high levels being used, not the fact that the nitrogen is synthetic.
5) “Synthetic fertilizers deplete the soil of nutrients” – how can that possibly be true? They are adding nutrients.
6) “produce malnourished crops of poor nutritional quality” – show me the science that this is true. https://www.gardenmyths.com/soil-fertility-decreasing/
You can’t blame all bad agricultural practices on synthetic fertilizer. In order to prove the problem is due to the fertilizer you have to separate out all of the other practices. For example, In a no-till condition does synthetic fertilizer reduce organic matter? Or is the tilling the problem? Or is it the high levels of nutrients?
I would have thought the opposite Alan 😉