(How) does the home gardener tithe?
This past year I grew some vegetables for the first time. I don't live in Eretz Yisrael, so I know I don't have to tithe my produce, but it made me wonder: what if I did? How would I go about that, practically speaking? Or is there a minimum amount below which tithing laws don't apply, and my couple of tomato plants and similar wouldn't count?
If you need to tithe from your vegetable garden, how do you go about it, practically speaking? How do you establish valuation -- compare to what's for sale in the grocery store?
I know that when shopping for produce in Israel I need to look for the certification that it's already been tithed, so I can meet my obligations without doing anything myself other than buying approved goods. Because of this, I'm not aware of how somebody would tithe in general, for example if one bought produce that hasn't been tithed. Maybe that's the same whether you bought or grew the food, but I don't want to assume that.