Ans: Though it is legal to grow both medical and recreational cannabis in Massachusetts, You can grow at most six cannabis seeds simultaneously. Further, check out the following points to have clarity. You can have up to 10 ounces of cannabis at home. However, if you don't have a medical marijuana card, you can have upto an ounce of cannabis. The good news is that with a medical marijuana license, you can have upto a 60-day supply of cannabis.