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My potted tomatoes are developing a very pale leafs at the start of growing tips - typical of sulphur deficiency.

I am interested in how much sulphur should be added to soil? What are typical concentrations of sulphur in soil?

These are the images. They were taken once the progression already took place. At the start, only the growing tips were pale. The other issue that springed to mind is root space. This plant is huge and was cut down periodically to foster lateral growth instead of one apex.

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  • Do you have a photo. I would not say sulphur deficiency so easily. Sulphur is frequent in soil because air pollution and because many anti-parasites contain it (it is a good fungicide). – Giacomo Catenazzi Jul 25 '17 at 13:21
  • @GiacomoCatenazzi Actually a lecturer told us atmospheric sulphur levels are dropping rapidly as coal power stations get phased out, to the point it is being added as fertiliser to fields. – Nic Jul 25 '17 at 20:57
  • Good question. I don't really have an answer, but you might try adding some ferrous sulfate heptahydrate (or any sulfate fertilizer or soil amendment in recommended amounts for that particular one; e.g. ammonium sulfate, potassium sulfate, etc. It'll probably be enough to correct a sulfur deficiency, I'm guessing) greenwaybiotech.com/collections/raw-chemicals-compounds/… Have you ruled out iron deficiency? – Brōtsyorfuzthrāx Jul 26 '17 at 5:54
  • How large are your plants? – Brōtsyorfuzthrāx Jul 26 '17 at 5:56
  • @nic: nice! (your comment, and that sulphur on air is dropping) – Giacomo Catenazzi Jul 26 '17 at 6:16
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Deficiencies of immobile plant nutrients are common in tomatoes, but are easily solved without actually adding anything to the soil!

Immobile nutrients can only be transported, in solution, in the xylem vessels and not the phloem. This means it cannot relocate sulphur once is in place, ie from older leaves. Sap flow in the xylem is predominantly driven by transpiration. The main factors affecting transpiration are temperature and wind.

If there is insufficient air circulation in your growing area then the transpiration rate is going to be slow, so the tomatoes will struggle to drink up enough dissolved sulphur to their leaves.

If you are growing the plants indoors, then a desktop or computer fan over the plants leaves will be enough.

In a greenhouse, try leaving the doors open during the day and night. This is why commercial polytunnels often have mesh doors instead of solid doors.

I'm not so sure what the solution is they're grown outside, perhaps somebody else has experience of this.

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Sulfur is only needed in small amounts as a micronutrient, and the signs are typically long woody stems and pale yellow-green lower leaves. It is hard to say which nutrient deficiency is affecting your plants without a photo.

I've been watching MIgardner's youtube channel for about two years, and he gives great advice on all kinds of garden fruits and vegetables and tips on growing plants in containers. Above I linked his video on container tomatoes.

This year I purchased some of his fertilizer called Trifecta plus and my tomato plants are enormous, lush and very productive. I have no affiliation with MIgardner, but I wish I did because his products are amazing! You don't need to purchase fertilizer if you have access to compost. Many townships make their own and give it away for free. Tomatoes are very heavy feeders, and especially when grown in containers they need access to nutrients so I would say an addition of compost or fertilizer will certainly help provide whatever nutrients your tomatoes need.

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  • No, sulphur is increasingly considered to be a macronutrient - smart-fertilizer.com/articles/sulfur . secondly, it is immobile in plants so symptoms if deficiencies will always appear on younger leaves. Discoloration on lower leaves is typically a symptom of deficiency of a mobile nutrient – Nic Jul 25 '17 at 20:42
  • Thanks. I am glad you found his channel helpful. Personally I think it takes him WAAAAAAY to long to get to the point. – sanjihan Jul 27 '17 at 13:06
  • Totally agree! His videos are too long for the content provided but I enjoy his gardening style so I usually compromise and watch his videos in fast forward. – MyNameisTK Jul 27 '17 at 13:31

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