Right now I am working at the client side, to allow 'baby objects'. basically, a baby object will have the same shape of a big object, however we'll use scalef() to make it look smaller.
I didn't try it yet, but the results should be satisfactory, I hope. In order to save some bandwidth, a baby object will be transmited to the server without any additional field. Instead, it's size will be encoded in the object id field.
The object id is an unsigned int 16. We will never have more than 8192 different objects (curently we have a little more than 1K), so we can use the last 3 bites for the object size. This way, we will have 8 different sizes for each object, at no cost in bandwidth or disk size.
Right now it's snowing a lot outside, so if the roads will be bad in the morning I'll stay home and finish the baby objects. If the roads will be good, we'll go to work, and if I am not too tired when I come home, I hope to almost finish them tomorrow.
The plant-growing system sounds really neat; I'd love to have a little house where I can cultivate weird varieties of game plants.