When I cast one of the soil preparation spells on those nice lush lawns of the Tranquil Cottage (bought from the Mooshu castle vendor) no plots of prepared soil appear, so you cannot garden -- unless you want to use pots, which is silly with those big open areas.
I wonder if it's because the grass is a much brighter green than that of the Wooded Cottage and the Royal Playhouse, in both of which I have created plots of soil. Perhaps that grass type wasn't flagged as gardenable. A pity, as I think the preview-lady even mentions a garden as an option.
(After purchasing it, I realized it has the same small 50 item outdoor limit like the Wooded Cottage, so it's not good for a large garden anyway, but that's not a bug per se.)
