50 Multi-Varieties Iris Seeds, Heirloom Iris Some of the small ones can be sprinkled right on the soil surface. Larger seeds will need to be buried. After planting seeds, you have to moisten the newly planted seeds. To speed up germination, cover the pots with wet paper or a plastic dome. This helps keep the seeds moist before they germinate. When you see the first signs of green, you have to remove the cover.