Those growing Purple Punch with standard or feminized seeds should expect to pay $10-15 per seed. Growing Purple Punch with standard or feminized seeds is considered to be easy and produces a medium yield. The healthiest Purple Punch plants will grow to be short to medium in height, especially when grown in soil. Flowering time for Purple Punch is 8-9 weeks. With all of this said, if you’re growing Purple Punch with auto-flowering seeds, you can expect the process to look slightly different. Auto-flowering seeds will flower automatically regardless of the light cycle, and will usually be ready to harvest in 8-9 weeks from seed.