Disease or deficiency?

[simonh82]

I recently purchased some baby tomato plants with the intention of planting some out and keeping some in the greenhouse.

The selection at the shop was pretty poor and most of them looked like they could do with a good watering. With the long holiday weekend ahead I decided to buy them anyway and thought they would soon perk up when I got them home.

Most of them have indeed perked up fine but I noticed that a few of the plants have white spots on the leaves and in the worst case the leaves are curled and dried up.

Is this a disease or some kind of deficiency? My guess is that it's a disease because they are only young plants but I'm no expert.

Should I just bin them, or is there anything I can do?

[applestar]

I think they are sunburnt. Likely those leaves were drying out from wilting and were unable to withstand exposure to any amount of sun. Lower leaves that start to show distress should just be clipped off — they are disease and pest magnets. The young plant will respond by pushing to grow more at the top.

With the multi-leaflet regular tomato leaves like this, you can just clip off the damaged leaflets and keep the good ones.

[rainbowgardener]

I agree, sunscald. It usually happens when plants, especially younger ones, have been kept in some protected situation and then are put directly out in the sun without being hardened off (gradually acclimatized to it).

[simonh82]

Thanks, I hope that's the case. I always thought hardening off was to acclimatise plants to cold conditions after starting them off in the warm. I didn't realise that it could also apply when putting them out in the sun.

Out back garden where they will be growing is a little more shaded so will hopefully be fine.

[rainbowgardener]

The burned leaves will not recover and should be removed, as applestar suggested. The new leaves that appear should be fine.