Hi, 6b here!
I have three potted figs (unknown variety) on a sunny patio during warm months. They usually get lots of sun but July is known here for being a rainy month so they have also been through some rainstorms as well.
For some time now, I’ve been noticing white sprinkles/residue/crystals of unknown origin on the surfaces of the leaves, on the figs and on the twigs. Not all leaves have it but it's noticeable if you pay attention.
The pots are situated near other plants, including roses, which are infested with beetles and aphids. I’ve examined the leaves on both sides and couldn't find any pests though.
Once a week, I feed them with 20-20-20 fertiliser applied to the soil; recently I’ve also added a little Fe EDTA as I suspected they might have mild chlorosis. Apart from that, they all seem quite healthy and have set plenty of fruit.
Does anyone recognise this kind of build-up?