AusBonsai

So I dug out this "rock basin"/flower-space in my garden today and was thinking of letting some of my Chinese Elm cuttings live there. (Unsure of level of drainage atm, will test with hose tomorrow.)
Questions:

1. How much worse would this be compared to actual ground growing? (Assuming you would otherwise bury a colander-like pot in the actual ground) The positioning of the pit in the garden is good.

2. With what would you fill this pit?

Thanks in advance!
/Per

Chinese Elms are tough so I wouldn’t worry too much. Good garden soil will do the trick. I assume it drains well into the garden? Not just a concrete slab planter? Just remember once in the garden it will grow very quickly you will need to dig it up seasonally to cut back the roots and then replant if you want it to grow bigger.
Cheers
Kirky

You have one rocky garden there Per!
Any container that is larger than the current pot will give extra growth and this is a larger container than most of our regular pots.
I can see a slab of rock under part of that area but not clear if it continues under the rock wall to the left. I assume it does not so water should be able to drain away OK.
Even though this garden bed will be shallow it will still allow roots to grow provided you can water enough to keep the plants growing. You probably won't get quite as much growth as a really deep fertile garden but should get some increase over pots. I think that water and fertilizer will be the keys to maximizing growth potential in this bed.
The shallow soil will have one advantage that it should be easier to dig the trees out when it is time.

Cheers guys I really appreciate your answers! Since there have been flowers and such there and not just a mud pool after rain it should drain okay, but I'll test it first so I'll get a sense of how effective the drainage is.

@shibui and the rocky garden: It is sort of the problem with our entire neighbourhood, it's just one big rock slab underneath! Parts of our garden only have about 10 cm of dirt before you hit "rock bottom"..