You shouldn't have much difficulty in growing them in zone 7......in fact, your difficulty may be in trying to contain them :-) They are not fussy about planting conditions or soil depth. IME, they will grow ANYWHERE and with great vigor. And I wish they resented root disturbance - I've been attempting to eradicate them from portions of my garden for years but even a small piece of rootlet will result in another, rampant clump. And they seed easily. These are ligtu hybrids as well as a named form that was supposedly more restrained in habit. Not!!

I would consider sinking the potted plant a very viable option - in fact I think I would recommend it over planting these thugs directly in the ground to run amuck.

You did not say, but I will guess these are in one gallon pots. In this one season they will fill the pots with roots and be growing out the holes. I fear if you sink the pot in the garden you will never be able to get it back up as it will be permanently attached. Al

Thanks to both of you for the heads-up about this plant!
It is now in a 5" pot. I will probably repot up to an 8"-10" size and place that in the center of a large sandstone slab!! I already have several thugs running amuck in the garden(3 Ferns, Arum italicum, Polygonatum odoratum 'Variegatum' & Disporum sessile 'Variegatum') and I definitely do not want another one!
Thanks!
Rb

Rb, suggestion to plant them at 8" depth is for the colder zones. Here in 6b they are not invasive at all and even sometimes disappear without the traces if winter mulch was forgotten. I have one clump running for four years and the major width-growth occured in years #1 and 2. In a subsequent years there were no progressions.

I am sure the climate will make a difference on the culture of Alstroemerias. Here in mild winter zone 9 they grow rapidly in January and February and end up with tall blind stems. I pull all the early stems and the plants respond with new growth that will bloom at about two feet high. If I don't do this the early stems will simply fall over and delay the production of new flowering stems. Al

If what you bought are some of the newer hybrids (Aztec Princess et al) then they will grow and flower in a two gallon container - with one proviso: they seem to need annual repotting and thinning out of the roots otherwise they get Grumpy and fail to thrive. Even if you feed them.

The species ones all definitely have Thug tendencies. They dig in deeply - many inches down, and coyly wrap their roots around those of any nearby shrub.

In addition to digging up any piece that shows itself, annual smothering with thick layers of leaves seems to help. They don't seem to do well in rich conditions. (Heh! Heh! Heh!)

How do alstroemerias do up here in zones 4 and 5?

craftygirl, alstroemerias will not be hardy for you. You could try to grow them in containers that can be overwintered in a protected location, but you'd just be tossing your money away if you planted them in the ground. As you might have deteremined from the previous posts, they are not the easiest to dig to remove or relocate :-)