How big will my yucca grow if I plant it in the ground?

[TheFarSide]

It's already been living outside in a pot for around 10 years and has survived the harsh recent winters. It's 7ft tall with three massive branches and a thick trunk that almost fills the pot, which has a 2ft diameter. Is it safe to transplant it into the garden, or will it grow to 100ft? It's a tiny London garden, mostly concrete and not much soil space.

Give it a good soak to get it out of the pot and loosen/hack back the roots so you have a smaller rootball. Pop it in a bucket of water and something like Seasol to cheer it up. Dig as deep a hole as you can manage, and wide enough for the rootball. You'll need someone to hold the yucca up while you level it so it doesn't rock, being so heavy. Although they can cope with neglect, they won't say no to bone and meal/chook pellets.

I'd this when the soil warms up a bit.

We had one in our London garden in a west-facing position and it did well.
They grow about 10 feet tall in Melbourne, so will probably manage the same. I'm about to hack off a huge off-shoot of my yucca, which is bullying a frangipani. They're unstoppable here. :o

Many thanks echt - just read your reply. 10ft sounds manageable. Do you know how far the roots spread?

Huge. The trouble is they also spread horizontally. I am a bit scared of mine as I can't really get near it to do anything much to contain it. They are very sharp!

I have inherited a Yukka in my new garden and it is about 10 feet tall. Not particularly wide though. It has grown straight up with 2 heads, one half way up.

I'm still pondering what to do. Based on what you've all said, it probably won't take over too much ... but getting it out of the pot and into the ground is going to be a hassle, more so because it will mean digging up a bay tree to make space.

Now, putting the bay tree in the ground was definitely a mistake. It started off as a small herb on my kitchen window sill and has grown into a monster.

Problems, problems ...

You might have to break the pot to get it out, but, unlike the bay, it won't take over.