Any idea what's up with these plants? I have eight tomatoes growing in the greenhouse, all in the same soil. Five of them are doing very well, but I have three with leaves that look like this, to varying degrees. All of the plants have been watered and fertilised in the same way.

These three problem plants are all next to each other. They were all very healthy when planted, and this colouration has only come on in the last few weeks. The varieties are Bountiful, Burlesque and Pink Honeymoon (all hybrids).

I am considering ripping them out and planting some spares, as I really don't want to lose the productivity from almost half of the greenhouse tomatoes. Assuming it was a nutrient deficiency, I fed them with some soluble 3-1-2 the other day to see if they would perk up, but it hasn't made much of a difference.

Looks like a basic nitrogen deficiency. Maybe your fertilizer is not complete? Of course, plants to react differently when grown in containers......

All of the leaves? or only the bottom leaves?

It can take days to SEE results of water soluble fertilizer, even though the plant uptakes it very quickly.

Yeah that is definitely nutrient deficiency in my books. The leaves are evenly discolored/yellowed without a sign of 'spots' or necrosis or patterning.. Feed em up is what I would do.
And fwiw, I had a few lower leaves like that on plants that were transplanted in a fairly mature state, I just pick em off and let the plant make new ones. Sometimes it takes a bit for them to get roots adequate for the whole plant supply, and they go ahead and drop the lower leaf that isn't getting as much light.
Lack of light on lower leaves, often a factor in the plant decision to pull their nitrogen and use it up top.
If I don't see telltale spots, an evenly pale or yellowed leaf at the bottom is a sign of good disease resistance in the plant.

https://www.haifa-group.com/online-expe ... deficiency

I don’t know how useful this is, but the link has photos of about a dozen deficiencies in tomato foliage.

I’ve had my tomato plants look somewhat like the photos in the OP early in the season when I let them get too chilled, that combination of purple with the sickly yellow green. This would be mostly prior to transplant and the plants always snap out of it once things warm up and they get the appropriate care. Doesn’t cool soil lead to phosphorus deficiency in tomato foliage.


https://www.accuweather.com/en/gb/londo ... her/328328

London weather looks to have been quite cool recently, at least as far as tomatoes might enjoy. Don’t know the situation in your greenhouse, but I would rather expect my tomatoes to have the look I see in the OP if grown in weather like London has had in June.

Cool and wet weather can contribute to root rot, which displays as nutrient deficiencies.

Cole_Robbie wrote: ↑Tue Jun 18, 2024 4:37 pm Cool and wet weather can contribute to root rot, which displays as nutrient deficiencies.

I don’t know the specifics about the OP’s greenhouse or exact location in the UK, but look at these temperatures recorded in London for June 2024 and see if you think they are sufficiently cool to cause nutrient deficiencies.

karstopography wrote: ↑Tue Jun 18, 2024 4:40 pm

Cole_Robbie wrote: ↑Tue Jun 18, 2024 4:37 pm Cool and wet weather can contribute to root rot, which displays as nutrient deficiencies.

I don’t know the specifics about the OP’s greenhouse or exact location in the UK, but look at these temperatures recorded in London for June 2024 and see if you think they are sufficiently cool to cause nutrient deficiencies. IMG_6806.jpeg

Yeah, certainly possible. A lot depends on the soil or media. Organic mixes are less tolerant of cold temps, as they rely on microbial activity, a lack of which could be the problem in cold weather regardless. The bacteria and fungi that are responsible for nutrient uptake can't multiply fast enough, and get out competed by anaerobic counterparts like pythium.

It looks like a phosphorous deficiency. When temps are cold, the plants have a hard time absorbing it. Remove those leaves and as soon as it warms up, it should correct itself.

Thank you all for your input.

I do think it is a nutrient deficiency, but am confused as to why only these three plants are this colour when the other five in the same greenhouse border are much more dark green.

Here's a better photo which shows some of the pale three's neighbours:
I am further north than London, closer to Liverpool. We haven't had much sun recently, it's been very overcast, windy and wet and the the nights have been quite cool (I don't think I've had to wear two jumpers in June before!).

The drip irrigation is new for this year, so perhaps I have been giving them too much water for the scant sun and cool temperatures. I have about 27 plants outdoors which look better than these three, though, and they've been battered by the wind and rain.

I will stop watering for a week or two, and foliar feed instead. Fingers crossed they green back up!

Overly moist for the cool weather is a really good bet.
IDK what varieties you are growing, but I often see reactions that are variety-specific. Some tomatoes tolerate cool conditions much better than others. So that might explain the differences. Seed source can make a difference too - seed from plants grown in your environment have a head start due to epigenetic changes to adapt to your climate.
Another possibility is that the yellowing plants are not draining as well. Due to whatever accidents of subsoil/ whatever's beneath the bed.

sometimes I dig up and start over same plants different soil
I had to do that with my wispy plants and banana legs.
Banana legs were the same size as weeks ago even indoors under lights.

Well, today was the last straw for the three poorly plants (Burlesque, Bountiful and Rose Crush). I think I got 3 fruit in total from them. They were very easy to pull out and had the smallest root systems I've ever seen on a tomato plant. You can see how skinny the stems are on some of the remaining non-grafted plants.

Luckily the grafted Polaris and Big Daddy are romping away and I've got three stems on each to make up for the plants which haven't done well.

I think there's something wrong with the soil on this side of the greenhouse, since the chillies have also grown poorly and barely set any fruit. Last year I had some jalapenos get some sort of root rot, and half of the tomatoes grew poorly. It's strange because the sweet peppers are doing great, probably the best I've ever grown, in the same soil 2 ft away on the other side (the two borders are separated by a 2x2ft paving slab, but the soil continues underneath), and I've grown tomatoes in that side too before with great success.

This is the second poor year in a row in this soil so I will not be growing tomatoes in it again.

Short plant, my size 8 foot for reference:
Small root systems:
Close up of the roots:
Skinny stem #1:
Skinny stem #2:
Polaris on Estamino rootstock:

I wonder if pH might be the problem? That's another factor for phosphorus uptake, besides other causes mentioned.

I don't understand how the pH of the soil on that side would be so different to the pH of the soil 2 ft away, though? It's a perplexing situation, it's essentially the same soil that all of these plants are growing in, but only the two grafted tomatoes are growing well and the sweet peppers on the other side are flourishing. Both sides have been fertilised and watered in exactly the same way.

We only used to grow in containers in the greenhouse, so both sides were previously covered in weed membrane and pebbles until a few years ago. The tomatoes grew so well in the good side the first year that I uncovered the second (poor) side too. I switched from growing tomatoes in the good side to the poor side because they would shade the sweet peppers too much.

I grow leafy brassicas, chard, lettuce, claytonia and alliums in this soil through autumn, winter and spring with no issues, and both sides perform equally well.

The only difference I can think of is that I have raspberries growing outside the greenhouse on the poor growth side, and their roots may have got under the concrete footings and into the greenhouse soil.

I was thinking pH changes could creep in if for example there was a bit of cement on the downward side of that paving slab, leaching into the soil in that one patch.
Raspberry roots is a definite possibility... one of the worst and rootiest weeds, in my experience.

I'm still not really sure what caused the problems with these plants. Here's a picture of part of the room system of my Big Daddy plant which was on Estamino rootstock. Both the Big Daddy and Polaris eventually put out a ton of tomatoes, even though a lot of them didn't ripen on the plant due to our poor summer. The grafted plants doing well would suggest a disease in the soil, but I still can't explain why the peppers on the other side of the greenhouse have done so well.