Pruning indeterminate tomato plants as fall approaches?

[JerryHaskins]

Sorry if this has already been covered but my indeterminate tomato plants (mostly Better Boy and Jet Star) have about reached their end-of-life due to the summer heat. Many of the branches are turning brown and drying up.

This is standard tomato plant behavior in the South around July and August.

I have continued to water and fertilize them regularly.

Last year about this time I pruned my tomato plants back and began harvesting ripe tomatoes again as soon as the weather cooled a bit.

As I recall, I picked small ripe tomatoes as late as Thanksgiving.

But now I cannot remember if I pruned the main stalk of the plants or just the side branches. And I cannot remember how severely I cut them back.

My Google search was pretty useless.

Anybody got any insight or guidance on pruning indeterminate tomato plants as fall approaches?

Thannks.

[PhilaGardener]

I suspect you will get a wide range of opinions on this.
How about an experiment? Prune some plants and leave others untouched for a side-to-side comparison in your garden. Let us know what you find!

[Father'sDaughter]

I know there are growers who will "top" their plants once it's late enough that any new fruit set will not ripen before frost kills the plants. The theory being that the plant will put all it's energy into ripening the fruit already on the plant.

In the past mine have always died from soil disease before I would have needed to consider topping them. This year I grafted and I have quite a few that will be candidates for trying it within the next week or two. Or, I may just let them go a bit longer and hope for a late frost this year.

[crmauch]

How many days before the last frost would one top a tomato plant (I'm assuming here that the tomato is surviving and you want the youngest tomato flowers to reach 'breaker' stage (ripe enough to ripen inside once picked). I know there is a dependency on how long a tomato variety takes to go from flower to ripe fruit.

I've heard the general range is 45 to 65 days to go from flower to ripe fruit (and towards the end of the season with cooler temperatures and less light I assume this would take longer)

So would a good estimate be to top tomatoes 60 days before the estimated last frost free date?

I've been told in the past our average last frost free date would be between October 10 - 15. Assuming, Oct 10th that would put the date for 'topping' at around August 11th?

Or since the 'goal' is 'breaker' stage would you top at a slightly later date?

What are the arguments for and against topping?

[bower]

I did my high canopy pruning and topping in the greenhouse on Tuesday a couple days ago. Yes I reckon a typical 45-50 days from set to ripe (or more if later in the season) and I don't want my plants to set more tomatoes that I'll be waiting for in October. The light is far gone here by mid October so the only maters worth having are grow-in-the-dark varieties.

Couple of reasons to top them now. Main reason is that as the weather gets cooler there will be more source of disease high on the plant and falling down on the fruit which still have to grow and ripen. That means either high maintenance for a low return, or loss of fruit by neglect. Neither appeals to me. I get tired of scouting for mold once it gets above my reach. Spent flowers in the high canopy are like mold bombs especially as the nights get colder and the weather gets wetter. Then the plants start to rot in earnest, and the daily grind is to hack off and bring out your dead. The smaller the plants are the better, and believe me they are already not small. I'm trying to follow good example and working on the thinning now even before the leaves get funky.

The plants are already loaded with fruit up to the rafters and nothing to do up higher but make trouble. I have way more tomatoes already set than I could possibly eat in a year fresh or frozen. So it is even more pointless to keep the plants going with new blossoms and set.

My only regret is that I might like to do a late cross or two if there was still pollen and mother flowers available. But I can't do that on a ladder anyway - I'm just not ept enough. Meanwhile if all these tomatoes ripened and the plants cut down and put out, I still have a dozen plants outdoors which are not overgrown and haven't been topped, and will very likely have fruit left to ripen that are too cold to do so... I could bring those in and have even more, more tomatoes than I can eat. Crazy and yet likely. Either that or I'll be sponsoring rodent festivities into happy new year.

This is a different situation from the OP obviously where a fall crop is possible after the heat passes. But pruning is any way you like it. If you want the main stem to keep getting longer then don't prune it. If you want some fresh stems, chop it all back. If you have any rotten stems get rid of them. Leave the healthy growth with the best chance of producing some flowers at the time when they can set.

[JerryHaskins]

Thanks everybody for the input.

I went ahead and cut most of my tomato plants way back. They were looking bad anyway.

If they die as a result or get done in by frost before they make ripe tomatoes, they had a good life . . . and there is always next year.

[zipcode]

Yeah, seems like a good plan. I think they will be fine. End of October I estimate you should have ripe fruits. Not sure when you expect frost, but I think it's later than that.

[taboule]

Bower's advice all makes sense.

Which makes me think, time for me to start topping. I already pulled out a couple of plants last week due to disease.

[Ricky Shaw]

Here's a neat pic of some aggressive regrowth after a stem has been topped for those that worry pruning may stress the plant. Olive Hill

I had some good success this year starting some of the big fruited varieties 4-stem in 10gal bags and after 3 clusters trimming to two stem. The root system and shoot seemed in better balance with less stress to the plant.

[b54red]

Originally Posted by JerryHaskins

Thanks everybody for the input.

I went ahead and cut most of my tomato plants way back. They were looking bad anyway.

If they die as a result or get done in by frost before they make ripe tomatoes, they had a good life . . . and there is always next year.

I don't know where you are in Mississippi but you are probably a bit early for topping down here; but since your plants looked bad it will work. If your plants have stopped producing and setting new fruit then you really needed to do something to get them back before fall. I recommend from past experience to water the heck out of them for a few days after topping in this heat and to give them a good dose of fertilizer. It will surprise you how fast a plant can come back in this heat. You also need to spray them with fungicide and watch closely for mites.

I planted a bed of nearly 20 new tomato plants just this past week in hopes of having more good fall tomatoes. The new plants are suffering some in this near 100 degree heat we are having every day despite forecasts of high 80s or low 90s. Yesterday it was forecast to hit 88 but instead it got to 100 and that is the way it has been for the past week or more. This kind of heat is an invitation to spider mites.

Bill

[JerryHaskins]

Thanks all.

b54red, I'm in Vicksburg. My greatest tomato problem this summer has been too much rain. We have already gotten close to our normal year's rainfall.

And it's supposed to rain every day next week.

My tomatoes were splitting as they got ripe, and lots of little bugs were loving the open tomato skins.

I also have had serious problem with the top of tomatoes staying green. And when that happens, they have a yucky green core inside.

[Emeoba69]

Thought I'd ask here instead of starting a new thread. Ive topped some of my tomatoes and left others alone as a sort of test. Im wondering how people manage the plant late in the season as the plants out grow their support? I made 6' rewire cages and my plants that aren't topped could easily be 9'+ so they are starting to sag with tomatoes set. Some are so large they have started falling over the next row. Ive had blight creeping up the plant at about 4 1/2 feet up the plant now. Wondering if topping them might end up letting the blight overtake the rest of the healthy leaves before the tomatoes and ripen? Let them go to allow for leaf growth?


Since this is my first season having my whole crop planted on time Ive still got a lot of learning on how people typically handle this stuff.

For reference

[Gardeneer]

I think topping is more for when you have a short season. Like in PNW it will get cold and wet in October even though the FFD happen around mid November. Up there I used to top and prune any buds/flowers about this time of the year ( mid August ) Any fruit set after that day wouldn't have a chance to get ripe.
But down south it is different. Most of my plants are not setting bt I just try to keep them alive. Com September , who knows, they might start setting. So then I will have ripe tomatoes in November.

[Spartanburg123]

Originally Posted by Emeoba69

Thought I'd ask here instead of starting a new thread. Ive topped some of my tomatoes and left others alone as a sort of test. Im wondering how people manage the plant late in the season as the plants out grow their support? I made 6' rewire cages and my plants that aren't topped could easily be 9'+ so they are starting to sag with tomatoes set. Some are so large they have started falling over the next row. Ive had blight creeping up the plant at about 4 1/2 feet up the plant now. Wondering if topping them might end up letting the blight overtake the rest of the healthy leaves before the tomatoes and ripen? Let them go to allow for leaf growth?


Since this is my first season having my whole crop planted on time Ive still got a lot of learning on how people typically handle this stuff.

For reference

I had the same problem with most of my plants- they became too tall and heavy near the top, and many of them started to lean and bend over into the next plant. Those heavy tomatoes at the top move the center of mass of the plant all over the place. You have a nice system there, your plants look manageable. You can either top them and let them sucker from down below, or carefully turn the vines and come back down the cage.