How to Grow Giant Sunflowers from Seed for Beginners Part 3, Potting up.again, So once your sunflowers get to this kind of size, then depending on what pot size you are using it would be If you'd like to save your California poppy seeds, here's what to do: wait until the pods turn tan and drygreen ones aren't viable. It's great to leave some to self sow, but 15 Cactus Plants to Grow BBC Gardeners World Magazine Strata 32cm Gothic Planter GN567 PEW ST Grey Planter