Those growing White Runtz with standard or feminized seeds should expect to pay $10-15 per seed. Growing White Runtz with standard or feminized seeds is considered to be hard and produces a medium yield. The healthiest White Runtz plants will grow to be short to medium, especially when grown in soil. Flowering time for White Runtz is 8-9 weeks. With all of this said, if you’re growing White Runtz 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.