Sweet Annie Wormwood Planting Poisons?

I have a wormwood plant, sweet annie, and I was recently told by another gardener that this plant poisons the earth around it so nothing else will grow there. Is this true? Also, I cut the plant down to the ground in the fall, and because it grows to 6 ft or more in height, I would like to move it. Do I move it now, or in the spring? Is it actually an annual or perennial?

We have not seen anything to suggest sweet annie (Artemisia annua) exudes poisons around it that would inhibit other plants from growing. We have grown it in our fields mixed with other herbs with no noticeable effect on neighbouring plants.
Sweet annie is an annual so there is no point in moving your plant. If your plant flowered and set seeds you may be able to move seedlings that appear next spring. The seedlings, if they come up, will likely be many and quite tiny at first, almost like a carpet. They can be moved at the stage when the seedlings have 3-5 sets of true leaves.