What soil deficiency makes Canadian thistles grow?

Question

What does our soil need in the garden? Lots of Canadian thistles are trying to grow, what does that mean? Is there a soil deficiency?

Answer 1

A little research shows that a deficiency of available phosphorus will encourage Canadian thistles.
Here's a good article for you: https://www.gardeningknowhow.com/plant-problems/weeds/canada-thistle-control.htm