your location.. big city name ...

Toronto

If by black gum you mean Nyssa sylvatica, they can grow in swamps so should be fine.

clay is usually very fertile.. and trees have no problem with such.. when they grow into it naturally ...

our problem is transplanting into the bad situation .. and getting it to live long enough to put its roots where it wants them.. and where they can cope ... the usual suspect in failure.. is watering a hole that doesnt drain properly ....

it is usually suggested ... that you plant high in good soil... lets call it a berm .... so the plant can be watered yet excess can drain away ... giving the plant that year or 3 it needs to grow the root mass to survive ..

good work on perking ... thats my usually starting point ... at least you know what you are dealing with below the surface ...

second.. never amend a planting hole .. it does nothing if its basically a ceramic pot that doesnt drain ...

lastly... trees never really stop growing at some magical height or width ... so when you say... something will fit there .. it is really only a question of how long it will take.. to outgrow it ...

perhaps a pic of the situation .. will get you some suggestions besides those you mention ...

ken

There is grass to the right, top and bottom (under deck). The bucket direction is a large stone patio. There won't be any stone against deck and to the right if need be but would like it to stay to give it a cutout look. The space in the picture is 7' x 7' opening.

Best case - a tree that loves water/clay and 30h x 15w.

Ok case - larger tree to try and keep smaller (single trunk river birch) that still tolerates this spot

Worst case - backfill with clay to allow drainage again, build up to a raised/open bottom bed and plant a Japanese lilac tree (or something)

Nightmare - put in a hot tub. :)

Appreciate your thoughts!!

Any help would be appreciated. I have dug down 24" leaving the middle "pedestal" about 18". I've used a 4' drill bit to see what else is below and about 8"-12" below the lowest point and once it penetrates that 8-12", it is quite soft and I can sink my entire bit in seconds. Seems like the heavy machinery that built the house, compacted it about 3 feet. Should I continue to dig around the middle to get to the soft/draining point?

I love that tree but I'm concerned about the size. I don't want this thing getting much bigger than 30' h x 15' w. In a 5b climate, does that sound reasonable? Maybe some light trimming?

Thanks Ken & Sara.
So I've done a lot of work on this hole to help prepare it for a few years of growth until (as you said Ken, establishes itself).

• removed pavers and created shallow channels for water to move away from hole, put surrounding pavers back.
• dug a drainage hole, put a pump, gravel in that part so I can drain on demand
• created a undisturbed pedestal for tree to sit on so that water drains away from its feet
• dug out around it like a sloped donut toward drain hole
• drilled what seemed like 150 mini holes 4 feet deep x 3/4" in every direction. Surprised that after about 8", it easily went through soil

Without pumping, I woke up to a hole full of water after a rain... as expected. Minimal draining. Pumping, I can get it dry (no soil yet).

I think I need a tree that will tolerate constantly damp/wet soil but at this point it won't be a puddle. I've given it 7' of room as a headstart. So...

1. I still think a tree that doesn't mind wet feet or constantly moist soil would be the best. Ideas?

• American Hornbeam, Imperial Honeylocust, Western Catalpa, Black Gum,

2. I want to put compost/biofor in the hole to help work the clay. I also want soil that is draining to limit it holding onto water. What do you recommend backfilling in?

3. Option #2 would be to create a raised bed and put a tree form of a more shrubby species - jap lilac, Eastern redbud, amur maple

Thanks for your knowledge!
Aaron

Go with option #1 or 3. Unless you can amend a very wide area - like the entire projected root spread, not just the planting hole - you will create a bathtub or a planting hole that retains water even longer than the surrounding clay. And option #3 can be modified to just just a bermed or mounded planting area, rather than a complete or structured raised bed.

Hey Gardengal, what do you mean #1 or #3? I have made the hole already and created drainage, etc. So now it's either put a tree in it or build a raised bed above it. If I put a tree in it, what tree would you recommend and, how far above pavers should I put top of rootball? Thanks!!

I mean skip point 2 - amending or backfilling with anything other than the soil you dug out. My personal choice when working with a slow draining, heavy clay soil is to plant high. No dug hole but just set the tree where you want it on scruffed up soil and then mound soil around it.

Gotcha, thanks for clarifying! Would the roots dive deep enough to go under the pavers? That's a great idea to plant on top. Although I might have messed that up by disturbing the soil!

"Would the roots dive deep enough to go under the pavers?"

Yes :-)

Any 5b shade tree that you would recommend that may enjoy dipping its feet in the pool now and then?

Magnolia virginiana. Aesculus pavia, Styrax americanus(shrub). Quercus lyrata. Taxodium. Dawn redwood. Swamp white oak. Red maple.

Thanks Kevin, would a Freemanii Maple "Celebration" or American Hornbeam be ok?

Also thanks for suggestions, my concerns with these are:
Magnolia - can't find the Sweetbay up here
Buckeye, sweetbell - not a fan, not look I want
Cypress, Overcup Oak, Redwood, Swamp Oak - I think may get too big for next to patio
Red Maple - roots would lift pavers?

Freeman maples are crosses of Red Maple and Silver Maple. If you are worried about roots with Red Maples, then same applies to Freeman. American Hornbeam would work great, See if you can get one that has great red fall color. Johnson's Nursery in Wisconsin has bred a red fall color strain, and has a more upright version called 'Firespire'.