Using a medium to large sized outdoor plant container located in a shady location, scoop out an area deep and wide enough to fit your colonized substrate that you are going to use. Save the dirt that you scoop out of the plant. You will later use this to put on top of the substrate. Crumble the colonized substrate and fill up the hole you just scooped out of the plant. Remember to watch out for plant roots! You don't need to make the hole very deep. After you've filled up the hole with your crumbled colonized substrate, cover it up with the dirt that you scooped out. Cover the substrate completely about 1/4' to 1 inch.
Next, cover the innoculated area with saran wrap to help retain moisture and allow for mycelium to grow. You will leave this in place while the plant's substrate colonizes. When the mycelium has colonized through the top layer of soil, you will proceed to the next step. Pencils were used to hold down the saran wrap at the edges.
Now what you need to do is tape some pencils to the outside of the plant container. You can also use something of similar length and width of a pencil if you don't have any pencils. You'll also need to stick some pencils into the plant's dirt around your covered up colonized substrate. After you've taped enough pencils on the side as well as in the dirt, you're going to take some saran wrap and cover the tops of the pencils and the sides of the plant container. This will create a tent for your outdoor bed which will hold in humidity. You can use several sheets of saran wrap to make sure that there are no holes.
Mushrooms fruiting in the saran wrapped tent.
Mature Mushrooms of a different strain.
Sometimes mycelium will grow far into the plant soil deepwards and sideways allowing for a farther area to be covered as long as it is watered often and never allowed to dry and has plenty of shade. This will allow for flushes to appear later in the center of the plant(s) where humidity is the highest. Mycelium in plants can last years if never allowed to dry and if nutrients like worm casting broths are added at least once every season (4 times a year) or more.
(here's one kind of mushroom fungus that could invade and rival your plant patch)