Probably mildew, caused by excess moisture. If it's not too much try scooping a thin layer off and discard. I would not worry too much if the plants look healthy and they do. Nice to see curry leaf sprouts!

I wonder if its epsom salts; which many growers use on curry leaf.

Remy101: Congratulations, those plants do look healthy. And that white stuff is likely to be mildew, especially if your soil is rich in compost/manure and moisture.

As others mentioned, let the soil dry to get rid of it.

farm96744, what exactly does Epsom Salt do to grow curry plants? I'd love to hear more!

this is what the epsom marketing people have to say about it:
http://www.epsomsaltcouncil.org/news/articles/expert_growers_recommend_epsom_salt_for_gardening.php

it's just mag sulfate; which is missing in some fertilizers. maybe the rationale is that curry leaf trees have higher requirements. I had gotten a large bottle of foliage pro which has it so I don't plan on supplementing.

This post was edited by farm96744 on Fri, Mar 7, 14 at 1:48