How much nitrogen are you giving it?

How much nitrogen are you giving it?

I just bought it. it's fresh from the nursery. so my q is - could this be a mutation? there were only 2 pots with this variegation out of a dozen. in the same pot the one on the left only got a few small 1/4" green blotches here 'n there. on the marbled one the green is very prominent.

so nobody seen this before? no ideas?

That's no uncommon. More likely as a potted plant than in the ground

but what causes is? some kind of nutrient imbalance in potted plant? just curious if i can make the 2nd one look like that. it only has a few dark green spots about a nickel size. i really like the marbling effect. my previous miss muffets did not have it.