This last season I grafted most of my tomato plants to a rootstock called Colossus and had amazing success. As I prepare for next year's crop, I've been looking to buy more rootstock seed but can't seem to find any seed houses selling Colossus. I've found Maxifort, SuperNatural, and a few others that are named after a bunch of numbers and letters. I would prefer to use what I already have experience with but unless I can find a dealer, it would appear that I need use a different rootstock. Maxifort has been advertised as super vigorous while SuperNatural is advertised as being more balanced...whatever that means. I'd like to hear peoples experience with either of these rootstocks or others that are readily available on the market.