Which option is best for alliums?

HouseFinch

I have 72 allium bulbs that I planned to plant in my back border. Problem is a lot needs doing to prepare the area, and I won't be able to get to it until spring.

The following options are available:

• I can either plant them now and mark the area, ensuring it isn't disturbed when the other plants are moved next year. Not ideal, because I will have spots I won't be able to plant in.
  

• I could plant as many as possible in pots and transplant them later into the border when it is ready in spring. If so, will 2 gallon pots be sufficient? Any tips on how to give them their best chance? I presume if I sink the pots into the ground over winter they will do better than above-it worked for my blueberries last year.

• I suppose the third option would be to grow them in a holding bed, and transplant them in the spring when the bed is ready.

OH says the third option, because the others seem like a lot of additional work. I only suggest it because I was able to successfully/accidentally transplant the Chinese onions currently in my back border in early spring.

These are the varieties I am trying to grow.

Obelixx

I would go for option 2 so there is no root and shoot disturbance when you plant them out later.   Make sure you have twice the depth of soil/planting compost above the bulbs compared to the height of each bulb and leave a couple of centimetres between each bulb.   

They are reliably hardy down to -15C or so as long as they are not wet or frozen thru so either keep the pots in a sheltered space that doesn't get colder than that or plunge them in the ground till you're ready to plant them out permanently.  A raised holding bed would be perfect for that.

Here's some general allium care advice from the RHS.  Just folllow the links.  You can also check Purple Sensation on the same site - https://www.rhs.org.uk/plants/popular/allium/growing-guide 

https://www.rhs.org.uk/Plants/57088/i-Allium-hollandicum-i-Purple-Sensation/Details 

https://www.rhs.org.uk/Plants/58292/i-Allium-i-Gladiator/Details

Fairygirl

I'd second doing them in pots. You can pack them quite tightly in there too, as they won't be staying long term.
It's very easy to then plant them out, and you can separate them quite readily if you want them in a drift, rather than planting them as a complete 'pot' into a space. 

WillDB

I planted mine singly in 9cm pots and in threes in 1.5L pots. I just placed them against a fence over winter but in Canada perhaps you might want to take a little more care.

Ceres

I'd go for option 2 but leave them in the pots to flower to avoid root disturbance. You can sink the pots into the ground and plant the bulbs out when the they have finished flowering.

I'm guessing its cold and damp where you are during the winter or are you away from the coast?

HouseFinch

Thank you everyone! Historical average low for winter here is -21 C. I was digging around in the border this morning and now have a lot of space cleared. Perhaps some out, and some potted and stored in a poly tunnel-or greenhouse if we can manage one this year. Then I can tuck them into the bare spots that open up in the spring.

Good to know you can sneak a few into one pot @Fairygirl

Fairygirl

Yes - just keep them a wee bit protected if the temps get down low, just to be on the safe side. If they're planted nice and deep, they should be fine though.Group them together or fleece them, or stick them against a sheltered wall. If they're kept on the dry side it helps.
A good layer of snow, when it arrives, won't harm them