Outdoor tomatoes looking yellow at bottom

[TheCyclingProgrammer]

I've got three Gardeners Delight plants, two planted in my raised beds and one in a pot/growbag in the mini greenhouse. Both are growing OK and have their first flower trusses with a second starting to develop.

The one in the mini greenhouse looks a healthy shade of green all over. The two outside are yellowing towards the bottom and the upper leaves are curling inwards a bit.

I'm led to believe that the curling leaves could simply be because of the changes in temperature overnight - we have been getting around 9-12C overnight (although its getting warmer now) and around 20-22C in the day at the moment.

I'm not sure what could be causing the yellowing leaves. There should be plenty of nutrition in the soil - the raised beds were filled last Autumn with a sandy topsoil/compost mix and have had nothing planted in them before. They were topped up with some extra multipurpose compost last month and I also mixed in some Seafeed poultry manure + seaweed pellets before planting out the tomatoes. I'm reluctant to give them more fertiliser as I can't see how they could need more.

They've been kept watered and I've since mulched them with Stretch to help preserve moisture as we have hardly had any rain of late.

Any ideas? If they are still growing ok should I be worried?

Some photos here:

https://www.icloud.com/sharedalbum/#...4-A7D3B18F09C9
https://www.icloud.com/sharedalbum/#...1-558954F2BDC0
https://www.icloud.com/sharedalbum/#...9-23869219F4CB
https://www.icloud.com/sharedalbum/#...9-7E3C02EB8830

[nickdub]

Tops of the plants look to be a good green colour - that's the main thing as it shows they are growing and healthy - the bottom leaves don't look too bad, so probably no need to worry - it wouldn't do any harm to mist the leaves with some foliar feed like seaweed fertiliser, and it might help.

[lottie dolly]

I would not worry about them,they not look that bad at all,i had broad beans yellowing lower down,after the rain we had,i was supprized to see they were looking all green this afternoon,and they had been watered with saved rain water,twice during the hot spell,

[chillithyme]

Your tomatoe plants should be fine, my tomatoe leaves at the bottom sometimes turn yellow, as long as the rest is green it should be ok.you only really have to worry if it's the whole plant that has yellowing leaves.

[TheCyclingProgrammer]

Thanks for the reassurance everyone. It’s my first year growing tomatoes so wasn’t sure.

[chillithyme]

I'm sure you will do greatthe first year that I grew tomatoes I literally spent most of my free time with them, hehe, and I talked to them a lot too, apprantly they like the conversation

[Bluenowhere]

I potted mine on in the polytunnel to their final pots about two weeks ago. The bottom leaves, literally the bottom 6 leaves (rather than the very bottom set like often happen as they age) started turning yellow, very unhappy looking but new growth dark green.

Didn’t panic but memo to self in the week to get some seeweed feed even though they were planted in mpc with mpc mixed with well rotted manure at the bottom of the pot. Went down today and bottom leaves are now back to green. I’m thinking perhaps they got a bit cold and now it’s warmer at night they are happy again. Rather strange tbh as never seen leaves turn from yellow back to green but perhaps it was just strange conditions in our part of the world. So would be interesting to see what happen to yours.

[MarkPelican]

Like others say, the "problem" is probably just temperature variation. The only other possibility is magnesium deficiency (but I don't think it is). When tomatoes lack magnesium, they can take it from lower leaves to use at the growing point which turns the lower leaves yellow. The solution is NOT more nitrogen fertiliser, too much nitrogen can stop the plant taking up magnesium.

What soil have you got in your raised beds?

[TheCyclingProgrammer]

Raised beds were filled with a “vegetable soil mix” which was about a 50/50 mix of compost and a sandy screened topsoil. As ty weren’t quite full they were topped off with some Gromore vegetable compost and I further topped them up about a month ago with some MPC. They were mulched overwinter with Strulch.