From Ground: Start by liberally watering the yellow thistle plant a few hours before the transplant to dampen the soil, which makes extraction easier and less stressful for the plant. Using a shovel or garden spade, dig a generous circle around the plant, careful not to get too close to the main root system. Gradually work the spade under the plant, ensuring the root ball remains intact, and gently lift the plant out of the hole.
From Pot: For pot-grown yellow thistle, first water the plant and let it drain completely. Place your hand over the top of the pot, fingers spread around the plant's base, and turn the pot upside down. With your other hand, gently tap or squeeze it until the plant slides out, along with its roots and the soil attached.
From Seedling Tray: If the yellow thistle is coming from a seedling tray, again start by watering. Then, simply use your fingers or a small tool to gently push up from the bottom of the cell or pinch the stem-base to lift the seedling out, trying not to tug or damage the stem or roots.