Should I move my trees?

[OhTheSilence]

I have a narrow 2' garden border with a 6' catalpa and 10' fatsia japonica side by side. They've grown quite big and there's only 2' between the trunks of each tree. Is it too late in the year to move one of them? I have a bare patch on the other side of the garden to fill in.
I'm thinking of moving the catalpa but afraid I'll kill it as I can't dig up a big root ball due to the size of the border. Or should I just leave them, prune them back hard, and buy a new plant for the bare patch?

I’d leave them and buy a new one.

Definitely prune them and buy a new plant for the bare patch. Moving bigger plants is risky and it would be a real shame to lose them.

Thank you! Now I need to decide what plant to buy. Any recommendations? It will be next to a forsythia and it needs to grow tall and narrow in a shady spot, with low maintenance. Don't want anything that spreads or has runners.
I'm looking online at dogwood or red robin? No idea!

Dogwood spreads like mad! Hydrangeas do ok in semi shade or acers, but they're slow growing.

I have some lovely black bamboo (phyllostachys nigra) in a shady corner. They have done really well and are very low-maintenance. Unlike most bamboos, they are completely non-invasive.

Depends on the dogwood! The large flowered ones (cornus florida) I don't think run that much?

If you want to try moving trees or shrubs, early autumn is the best time of year to do it, not now.

Deutzia grow tall and thin, if you don't prune them, but possibly won't flower so much depending how shady it is.

Don't plant trees/shrubs now - it will stress them out too much as it's growing season. Fill that space with bedding plants and then plant something in the autumn. If you really want to move one of your existing trees, do it in November when it is pretty much dormant but before the ground is really cold.