Unlikely to work, I think. Fungi are quite specific in their requirements. Any that are suitable for your conditions will arrive on their own, just give it time.

Fly Agaric grow with silver birch, so first get your birch trees.

Then, if they don't show up on their own, after a few years, spend some time tramping about private woodlands, with the owner's permission, of course. When you find the kind of toadstool you want, take a few cu. cm of soil--again, with the owner's permission--right near the base of a few of the toadstools, and sprinkle in various moist places near the drip line of the trees. It may take a year or two to get toadstools, then.
One thing...please tell me that you aren't trying to grow magic mushrooms!!

Thanks Landgirl, this seems the way to go and we leave rotting wood around.
Stera, we have about 200 betula already :) So the horse is on front of the cart
Tug, brilliant advice, I wondered about this idea as I've read Buckingham palace have Fly agaric ? growing which came with bark mulch. Haha, no I don't want magic mushrooms just beautiful fungi.
Thanks

You are well set then Dawn. I really hope you find some - such a favourite "fairy" toadstool. They are magic mushrooms though, highly hallucinogenic. Did you know that the Inuit custom is (or was?) to note when their reindeer ate them and then to collect the urine to drink. Apparently you still get the "high" without the nasty side effects. A large group appeared in the birch wood of the college opposite where we used to live but the spoil sport groundsman went round and knocked them all down. Shame, they were so pretty.

Hi Stera, that's really interesting, thank you. What a shame the ones you saw were demolished, maybe the spores will continue long after the nasty groundsman is long gone. I will try and let the leaves build and fallen wood rot and cross my fingers. I will also be on the look out for fungi so I can collect the soil around the bottom.

Yes we were sad about it - but I guess the college authorities felt responsible for the health of any adventurous students on the campus.

Oh yes, never thought of the magic mushroom side of things.

They also form an association with Pine trees. I've seen them in kielder forest and Dalby forest. both heavily coniferous. they are also hallucinogenic but have many unpleasant side effects.

Collecting a soil sample is a good idea.

A form of this species is native to northern Arizona, but ours are not hallucinogenic, they are proteolytic--i.e., if you try to eat them, they will wind up eating you! The toxins in Fly Agaric are highly variable from form to form, making it highly dangerous to harvest or cultivate them.

Aside from my intentional or unintentional ( poor technique) planting of fungi in a petri dish or those who cultivate in enclosures for edible mushrooms, I don't think that there is a garden in the universe whose sole purpose is to display the living beauty of the fruiting bodies of fungus. If there is though, it would be a fascinating place to visit. A recollection just popped into my head where I read somewhere about a gardener who left compost to rot in plastic bags. He died of aspergillosis when he opened the bags and took too many toxic spores into his lungs while breathing. Of course he must have had some bad contributing health factors to succumb to this otherwise one would see the bodies of gardeners piled high by their compost bins everywhere.