Lilac in a container?
We've just picked up a Lilac (Syringa V. 'Monique Lemoine') at a garden center, to keep on our half-sun patio. (It gets light from about 6 AM to half past noon.)
It's just under 5 feet now (including the pot), and is in a 12" plastic nursery pot. Our intention is to keep it pruned back (Only prune immediately after blooming, I read) to about this size until we have a more permanent situation, and then to give it a permanent place in the ground.
How big a pot should it be in, if we annually prune it back to 5-7 feet?
How much root pruning should I do? Should that be done at the same time as the foliage?
Is the plant still cold-hardy in a container? We can see temperatures down to -10 F here in Montreal, although those days are rare.
What should I be doing for it's nutritional requirements? I'm typically a veggie guy, and composting in spring is about as complex as I get with ferts. I know it'll need frequent watering as it warms up, but how often should I feed, and with what?