Yes - repot if you're not planting them in the ground. When roots are showing at the base of any plant, it means they're outgrowing their space, so they need moved on
It's a place where beautiful isn't enough of a word....
I live in west central Scotland - not where that photo is...
I bought some giant alliums and they were expensive but looking forward to them flowering. Ideally they would be better in the ground, personally I would sink them in the ground when the weather gets better.
I think a east facing wall would be best for now good sun light but sheltered from to much rain so they don't rot.
I like christophii mass flowers and the dead flower heads last for ages. I have far to many alliums I barred myself from buying anymore the year
I be digging mine up if I was moving as well. I bought 15 for £40 I only wanted 3 Giganteum then I wanted another variety, I ended up with a collection 3 each of giganteum - globemaster - round and purple - white giant - mount everest . I probably planted 50ish allium last November already had about 70, not an incredible amount but probably to many for my limted space.
This a pic from last year of my small front border, purple senation - gladitor - mount everest.
aym - as your alliums are in pots, it's easy to have the right mix for them to do well, so you don't need to worry too much about them getting wet. They'd never grow at all up here if that was the case!
Most alliums prefer a decent bit of sun, so find a spot that gives them that. As they're in pots, they can get top heavy, so a site out of the prevailing wind is best, or somewhere that they can get support from other planting if you want to put them in a border in their pots.
Lovely pic Perki
It's a place where beautiful isn't enough of a word....
I live in west central Scotland - not where that photo is...
Thanks just another 5/half month to the next showing . That my pastel border I got another border in the front which is the hot border. The aquilegia are self seeded I spend more time removing them.
Aym280 your post got me thinking about my alliums, they were still in the pots I bought them in last March, I never did get round to planting them in the ground! I found on checking today they too are putting roots out through the base of the pots. The tops too were smothered in weed seedlings. I've tidied up the tops and will need to source some pots to pot them on since I have no tall ones to hand. Timely post I think.
I'm slightly confused. There's no benefit to a plant in putting it inside a bigger pot, while keeping it in the pot it's in, other than if you were concerned about it freezing.
Potting on won't disturb the roots to any great extent. I often pot on after cutting excess roots off the bottom of plants in order to get them out the pot to begin with. I've done it at lots of different times of the year, although a benign, mild spell of weather is always best.
Alliums are pretty tough - if they were mine, I'd get them into bigger pots now and give them a bit more depth. It helps with their stability too.
It's a place where beautiful isn't enough of a word....
I live in west central Scotland - not where that photo is...
Posts
Yes - repot if you're not planting them in the ground. When roots are showing at the base of any plant, it means they're outgrowing their space, so they need moved on
I live in west central Scotland - not where that photo is...
I bought some giant alliums and they were expensive but looking forward to them flowering. Ideally they would be better in the ground, personally I would sink them in the ground when the weather gets better.
I think a east facing wall would be best for now good sun light but sheltered from to much rain so they don't rot.
I like christophii mass flowers and the dead flower heads last for ages. I have far to many alliums
I barred myself from buying anymore the year 
I be digging mine up if I was moving as well. I bought 15 for £40 I only wanted 3 Giganteum then I wanted another variety, I ended up with a collection 3 each of giganteum - globemaster - round and purple - white giant - mount everest
. I probably planted 50ish allium last November already had about 70, not an incredible amount but probably to many for my limted space.
This a pic from last year of my small front border, purple senation - gladitor - mount everest.
Perki - lovely mix with the pink aquilegia.
aym - as your alliums are in pots, it's easy to have the right mix for them to do well, so you don't need to worry too much about them getting wet. They'd never grow at all up here if that was the case!
Most alliums prefer a decent bit of sun, so find a spot that gives them that. As they're in pots, they can get top heavy, so a site out of the prevailing wind is best, or somewhere that they can get support from other planting if you want to put them in a border in their pots.
Lovely pic Perki
I live in west central Scotland - not where that photo is...
Perki That is a lovely mixture of plants and colour.
It is good to see some real flowers even if its in photographs .
'You must have some bread with it me duck!'
Thanks
just another 5/half month to the next showing 
. That my pastel border I got another border in the front which is the hot border. The aquilegia are self seeded I spend more time removing them.
Last edited: 08 January 2017 17:18:24
Aym280 your post got me thinking about my alliums, they were still in the pots I bought them in last March, I never did get round to planting them in the ground! I found on checking today they too are putting roots out through the base of the pots. The tops too were smothered in weed seedlings. I've tidied up the tops and will need to source some pots to pot them on since I have no tall ones to hand. Timely post I think.
I'm slightly confused. There's no benefit to a plant in putting it inside a bigger pot, while keeping it in the pot it's in, other than if you were concerned about it freezing.
Potting on won't disturb the roots to any great extent. I often pot on after cutting excess roots off the bottom of plants in order to get them out the pot to begin with. I've done it at lots of different times of the year, although a benign, mild spell of weather is always best.
Alliums are pretty tough - if they were mine, I'd get them into bigger pots now and give them a bit more depth. It helps with their stability too.
I live in west central Scotland - not where that photo is...
Beautiful pic Perki, made me feel all summery