The double stem technique for growing tall tomato varieties is when a side shoot is allowed to grow (on a cordon/indeterminate variety) and become a second main stem. This has the advantage of growing more trusses and at a lower height.
It’s a method of training tomato plants that is frequently used in greenhouses to maximize the production from each plant. You get more tomatoes without the plants growing through the roof – they will if you let them!
Choose Hybrid & Grafted Cherry Plants
Hybrid tomato plants (F1’s) and plants that have been grafted, are usually more vigorous and ideal for this method of growing tomatoes.
Allowing more than one stem to grow on a tall variety is most successful on cherry varieties, where plants find it easier to bring tomatoes to maturity early.
It’s possible to grow more than two main stems …
This photo shows a Sungold (tall variety) that had an accident and lost its main stem – I dropped a sheet of plastic on it!
I’ve allowed three side shoots to grow – one either side (as marked) and one behind. Each new side shoot stem, can then grow more trusses.
For example, if I have one main stem and allow a side shoots to develop, I will end up with two stems.
I can grow trusses from each stem, making a total of as many trusses as I want.
A Longer Season Is Better For This Technique
In a good summer, I’ll end up with more tomatoes, than when growing just one stem with three trusses!
You may ask … how many trusses is it possible to grow?
If you live in an area where the growing season is short, and summers are often disappointing, then the fewer trusses you grow, the more chance there is of success.
In a greenhouse, where the growing season is extended, I sometimes grow more than four trusses on each stem.
Timing
It is best to do this in the first part of the season (during June) as side shoots can take a while to grow and produce trusses.
On a vigorous cherry variety like Sweet Aperitif (above), trusses will just do their thing. However, if growing a medium or large fruiting variety, trusses have to be pruned and managed correctly, to produce a good crop.
Dave Micle Galas
How do you move/drop them? I work in a greenhouse and started growing 2 stem method but stuck on how to drop them. We grow them on lines however we dont let them grow so much. We drop some of the strings where they are clipped on and move them to keep them on ideal height.
Nick
I move the lines at the top to the side, so that the stems are growing at an angle.
Nick
The main stem is left to grow as normal – the side shoot or shoots are allowed to grow from above the first or second leaf joint. Pinch out the main stem before the end of the season to encourage the other stem or stems to catch up.
David pro
Which sucker should I keep to create a two stem tomato
Nick
Keep the lowest or next lowest sucker if it’s healthy.
Anonymous
Do you increase the spacing you plant out the tomato plants at to allow more space for each plant, or do you just plant at the same spacing you would if growing one stem per plant? Either way what is the spacing you plant your tomato plants at?
Nick
I grow most of my plants in containers, so those that are fixed together such as, Oasesbox, Quadgrow Planter and the Autopot system are between around 15 to 24 inches apart.
In garden border I would space around 24 inches apart.
The above applies to tall, indeterminate varieties.
c
why is it that we don’t normally allow side shoots to grow?
Nick
Side shoots are usually removed from tall varieties to encourage the plant’s energy into the trusses which grow out of the main stem. The more side shoots you have, the slower the trusses will grow.
However, if you have a long growing season (unlike the UK) it won’t matter if it takes longer for the toms to mature because the growing conditions will still be good when they do.
Rhys Jaggar
My Alicante is a bit like this. I’ve just kept growing what I bought from the garden centre and now have 10 trusses on a plant which is only about 70cm high. I already have about 25 tomatoes set and growing and hopes for quite a lot more.
Can verify that this is a very good tip!