Purple spots on tomato leaves

[Eeilee]

Never seen this before. The lower leaves are getting these purple spots and some are curling.
Any ideas what’s causing this?
This is the first time I’ve grown them in grow bags.
I’m using 20 gallon bags with quality organic soil and have fertilized them once so far with tomato tone.

 

[Chuck]

I think you have the beginning of a potassium deficiency. When did you last fertilize them? Tomatoes should be well fertilized at least once per month, preferably every two weeks during their main growth period such as now. Also, this is what I believe is happening because of the color of the plant. It is not a dark green, it has a yellowish tint to the leaves. Also, it appears that some of the leaves may have a leathery texture to them, another sign of nutrient deficiency.

 

[Eeilee]

I think you have the beginning of a potassium deficiency. When did you last fertilize them? Tomatoes should be well fertilized at least once per month, preferably every two weeks during their main growth period such as now. Also, this is what I believe is happening because of the color of the plant. It is not a dark green, it has a yellowish tint to the leaves. Also, it appears that some of the leaves may have a leathery texture to them, another sign of nutrient deficiency.

I fertilized them about 3 weeks ago.
I’ll fertilize them again next time I water them. And you are right - I noticed the ones in the grow bags are not as green as the ones in the ground.
I have a bag of dr earth for tomatoes. I’ll dig some of that down into the soil and see if that helps.
Despite deep watering I’ve also noticed the grow bag tomatoes roots are very close to the surface.

 

[Chuck]

I fertilized them about 3 weeks ago.
I’ll fertilize them again next time I water them. And you are right - I noticed the ones in the grow bags are not as green as the ones in the ground.
I have a bag of dr earth for tomatoes. I’ll dig some of that down into the soil and see if that helps.
Despite deep watering I’ve also noticed the grow bag tomatoes roots are very close to the surface.

This is the first year that I have grown all of my tomatoes and peppers in grow bags. I am growing 8 varieties of tomatoes, four of each variety, all of them with the exact same soil, same fertilization, .same everything and yet 2 varieties are showing the yellowness in all 8 of the plants. I am using 10 gallon bags. The transplants were all at least 16 inches tall and I buried them all very deep, at least 8 inches, just shy of the first set of true leaves and well above the cotyledon leaves. I am not showing any shallow roots except on one variety and they are the most vigorous and productive of the 8 varieties but surface roots are common for tomato plants. I am not showing any nutrient deficiencies but the yellowness disturbs me. I am out of Chelated Iron and am waiting for it to arrive on Wednesday when I am going to treat for the yellow with it. I suppose it is possible that the yellowness could be a varietal issue. In my case and possibly yours, it very well could be a micro-nutrient issue and not a fertilization issue. I will know for sure when I use the Chelated Iron.

 

[Eeilee]

It’s strange because my grow bag cucumbers look better than the ones in the ground and my tomatoes are the other way around.
I suspect you’re right though - in the ground our plant roots can find those micro nutrients ( assuming we have good ground soil)
I knew I’d have to water and fertilize more often in grow bags but I may have to step up my game.
I actually enjoy fussing over them so I don’t mind the added work.
I’m running out of space in my garden and wanted to double my produce this year; hence the addition of grow bags.
I think your 10 gallon is a better idea than these hefty 20 gallon. They are a bit unwieldy.
My cukes are growing beautifully in 15 gallon.

 

[Chuck]

It’s strange because my grow bag cucumbers look better than the ones in the ground and my tomatoes are the other way around.
I suspect you’re right though - in the ground our plant roots can find those micro nutrients ( assuming we have good ground soil)
I knew I’d have to water and fertilize more often in grow bags but I may have to step up my game.
I actually enjoy fussing over them so I don’t mind the added work.
I’m running out of space in my garden and wanted to double my produce this year; hence the addition of grow bags.
I think your 10 gallon is a better idea than these hefty 20 gallon. They are a bit unwieldy.
My cukes are growing beautifully in 15 gallon.

I just pickled 16 pints of dill pickles. I grow mine in 2 gallon pots and they do fine but I don't know how that small of a container would work in your climate where it is a lot cooler than it gets here and you have a longer growing season. Another month and it will be too hot for good cuc production here.

 

[Eeilee]

What are the 8 varieties of tomatoes you’re growing Chuck?
I’m just doing 4 types : Roma, beefsteak, better boy and cherry.
The Romas and San marzino ( really just Romas as well) I use for sauce and salsa making.
This is my first time growing better boys and they are the ones being the fussiest.
For pickling cukes I grow National pickling and Boston.
For succession planting this year I’m trying out some Sumters.

 

[Chuck]

What are the 8 varieties of tomatoes you’re growing Chuck?
I’m just doing 4 types : Roma, beefsteak, better boy and cherry.
The Romas and San marzino ( really just Romas as well) I use for sauce and salsa making.
This is my first time growing better boys and they are the ones being the fussiest.
For pickling cukes I grow National pickling and Boston.
For succession planting this year I’m trying out some Sumters.

Cherokee Purple, Carbon, Celebrity, Sungold, Arkansas Traveler, Costoluto Genevese, Super Sioux, Valley Cat. The cucs I am growing this year are 2 Straight 8 and 8 Triple Crop. I grew Sumters 3 years ago and they did great, very productive.