This is a question many people ask but no, you do not need a woodland to do forest school.
Forest School is an ethos, rather than a location. By creating the key elements to a forest school environment such as the fire circle, kitchen area and equipment store, you can create the same sort of environment as you would have in the woods. Teaching to the ethos of Forest School is the important ingredient and children will very quickly become used to a familiar space such as their outdoor area being used in a different context. A bit like using the hall for PE and lunch in the same day.
But what about the lack of trees? Luckily, I have a car with a big boot and no qualms about it getting dirty so I import sticks, fir cones and whatever else we need to make forest school happen. If you don’t like getting the boot dirty, ask the kids to collect some natural goodies. We had a ball foraging for sticks and cones along the edge of the school field; taking them back to the outdoor area and throwing them on the floor to be used whenever we needed them. The teachers thought I had a screw loose but it’s all making sense now because when we needed sticks for our fire today, the children were actually able to collect some!
It’s also a good idea to put out an appeal to parents to donate logs, sticks or cuttings to your cause.