Instructions
Plan when and where to plant. Thistle seeds should be planted in the spring after there is no more chance of frost. The plant takes four months to be harvest-ready and typically flowers from August to September and ripens from September and November. Two things to consider when deciding where to plant your thistle are sun and soil. Thistle is often grown in the sunny climate of Africa, and does best in full sun. It should be planted in rich soil, though this is not as big of a concern since the plant can survive in a variety of soil types.
Plant the seeds. To prepare the location you have chosen, fist remove all the weeds and spread a mixture of half peat moss and half garden soil over the area. Then sprinkle your seeds lightly onto the ground. Seeds should be covered with 1/2 inch of soil and 1-2 inches of mulch, which can take the form of peat moss or sawdust.
Water the seeds regularly to avoid postponing germination. Keep the soil moist but be sure not to flood the seeds. Thistle plants can grow up to six feet tall and almost as wide, so once they start sprouting, space the plants out every 6 inches or so and discard extras if necessary to prevent crowding.
Harvest. Once the yellow flower on the thistle transforms into seed pods, these can be harvested and used to feed domestic birds or left where they are for wild birds to eat. To ensure that the thistle comes back the next spring, leave a few seed heads so that the plant can reseed.
How to Grow Thissel for Feeding Birds
Thistle, also known as Niger or Nyjer, produces small black seeds that can be used to feed birds indoors and out. These seeds especially attract small songbirds like finches and redpolls. Because of the additional labor needed to harvest them, thistle seeds can be quite expensive in stores. To avoid cost and the middle man, you can grow and harvest your own thistle at home.