tommmy91
Full Member
Posts: 11
Joined: Wed May 17, 2017 10:48 am

Black edges on young tomato plants

Can anyone tell me what this is?
The underside of the leaves are purple. Other than this the plants look healthy. Theyve been in my greenhouse about a week and ive been constantly checking the temperature it hasnt gone below 13
Attachments
1495018218453-1607487465.jpg

User avatar
applestar
Mod
Posts: 28171
Joined: Thu May 01, 2008 11:21 pm
Location: Zone 6, NJ (3/M)4/E ~ 10/M

Re: Black edges on young tomato plants

Have you been using some kind of oil-based spray?
Learning never ends because we can share what we've learned. And in sharing our collective experiences, we gain deeper understanding of what we learned.

tommmy91
Full Member
Posts: 11
Joined: Wed May 17, 2017 10:48 am

Re: Black edges on young tomato plants

No i havent used anything ive just watered the plants but i havent touched or wet the leaves at all. My first thought was thw cold had got to them but it cant be that..

User avatar
rainbowgardener
Super Green Thumb
Posts: 25303
Joined: Sun Feb 15, 2009 11:04 pm
Location: TN/GA 7b

Re: Black edges on young tomato plants

The purple undersides of leaves are quite common in tomato seedlings grown inside under lights or exposed to cool temperatures.
Usually they grow out of it. If older plants still show purple, especially if the leaf veins are also purple, it is a sign of phosphorus deficiency. Add bone meal to the soil to help with that, but understand that the phosphorus doesn't become available until the bone meal breaks down further, so you won't see any instant change. Be careful not to over-water, which will make it worse.
Twitter account I manage for local Sierra Club: https://twitter.com/CherokeeGroupSC Facebook page I manage for them: https://www.facebook.com/groups/65310596576/ Come and find me and lots of great information, inspiration

tommmy91
Full Member
Posts: 11
Joined: Wed May 17, 2017 10:48 am

Re: Black edges on young tomato plants

Thanks i don't think its that though.. i didnt want to mention the purple leaves because i knew someone would pull it up as that. Its the black leaves that are really worrying to me. the leaves themselves feel normal

User avatar
applestar
Mod
Posts: 28171
Joined: Thu May 01, 2008 11:21 pm
Location: Zone 6, NJ (3/M)4/E ~ 10/M

Re: Black edges on young tomato plants

OK, I went around taking some pictures to show you. I have tomato seedlings that are deteriorating from mite infestation. My best guess right now is they are Broad Mites and not TRM's (tomato russet mites). They are microscopically invisible so I just go by the way the plants look rather than trying to see them or ID them.

See what you think. And maybe other folks could weigh in if you see (or NOT see) similarities here, too. I'm afraid I'm in "spot the infested tomato seedling mode" and might be seeing mite damage everywhere I look, regardless. :roll: The faint russeting -- brown-looking hairs, especially from the soil level up and then concentrating on the terminal leaf bud, rather than the pristine white/translucent downy hairs of healthy seedlings -- are the first suspect indication.


If you click/tap on the image, you will open a zoomed 2MP version.

The top LEFT photo shows seedlings that I am treating with home made oil/soap/alcohol mixture. The reason I asked about the oil treatment with yours is that I though I saw similar translucence in the leaves and oily sheen.

The other photos show seedlings at various levels of infestation. Ignore the white blotchy marks -- they are there because these are special, variegated leafed variety. I also have a potato leaf variety here. Focus more on the dark blotchy marks and slow crisping along the edges.

Image

Once the topmost growing leaf bud has been blasted, tomato seedlings that are trying to recover from infestation will grow a new side shoot from a lower leaf node, and if that doesn't get infested and taken down as well, they will recover (or they will try again and again from a lower node until they exhaust themselves). The seedlings that I'm not treating are nestled among pepper plants that recovered from its infestation after releasing predatory mites, and some are trying to grow new shoots. :-()
Learning never ends because we can share what we've learned. And in sharing our collective experiences, we gain deeper understanding of what we learned.

imafan26
Mod
Posts: 11585
Joined: Tue Jan 01, 2013 1:32 pm
Location: hawaii, zone 12a 587 ft elev.

Re: Black edges on young tomato plants

The other reason for young tomato seedlings to turn purple especially on the stem and undersides of the leaves would be that they lack phosphorus. If they have been in the pot too long, planting them out and feeding them should help.
Happy gardening in Hawaii. Gardens are where people grow.

tommmy91
Full Member
Posts: 11
Joined: Wed May 17, 2017 10:48 am

Re: Black edges on young tomato plants

Thank you all for your help ill keep an eye on my plants for mites. At the moment my leaves appear normal apart from the black marks. They are not dry or crispy infact they don't look like they could die at all.. they look really healthy as a whole. I might make up some homemade spray for them just incase thanks for the tip :D ill let you all know how they go on anyway if they end up dead ill blame you guys haha jokes. Ive got two healthy plants if they turn bad i just hope whatever is affecting them doesnt affect my healthy tomato plants which are a month older and have tomatoes on already :D

User avatar
KitchenGardener
Senior Member
Posts: 278
Joined: Tue Apr 26, 2016 12:30 am
Location: Northern California; Hardiness Zone 10a, Climate zone: 17

Re: Black edges on young tomato plants

So this may be coming out of left field, but are all your plants which present with this coloration the same variety? I have some tomato plants that are tinged with purple. I started my various varieties from seed in identical soil and only certain ones are purple tinged. I'm not too worried as I'm assuming its the varietal.

tommmy91
Full Member
Posts: 11
Joined: Wed May 17, 2017 10:48 am

Re: Black edges on young tomato plants

Purple leaves are no issue its just the cold 9 times out of ten i was worried about the black leaves on top. Anyway i believe the reason they went black was either because it got to cold at night or because of sun damage. i bought them from marshalls and i have a feeling theyve been under artificial light and not proper sun light and because ive left them out too long theyve got sun burn on the, top of the leaves. Ive stopped putting them out as much and chopped some of the black leaves off and theyve perked up so im hoping thats all it was :D

tommmy91
Full Member
Posts: 11
Joined: Wed May 17, 2017 10:48 am

Re: Black edges on young tomato plants

My plants look alot better now the blackness has gone pretty much but the leaves seem to be growing rather wierdly now for some reason... Heres some pictures of my progress and the strange leaves lol
Attachments
IMG_20170529_090321.jpg

User avatar
Gary350
Super Green Thumb
Posts: 5377
Joined: Mon Mar 23, 2009 5:59 pm
Location: TN. 50 years of gardening experience.

Re: Black edges on young tomato plants

Temperature 13 must be 13C that = 55F that is not bad for tomatoes but tomatoes do tend to turn a strange dark purple color when they get cold.

Return to “Vegetable Gardening Forum”