Growing position (and growth rate) of Syringa x Laciniata?

Nollie

I have just received this shrub as part of a larger online shrub order. It’s tiny - barely 15cm high in a 2L pot.

As it is allegedly one of the most heat-tolerant lilacs and likes full sun, I had planned to plant it in a large south-facing rockery-style border.  But researching growth rate, couldn’t find much on that, but read that it likes a cool root run. As this bed is a raised one constructed of stone and gets a thorough baking in summer I am now wondering if this is the right place for it...

I have an alternative location for it in the ground, but a bit smaller at around 1.5 x 1.5 metres. Does anyone know how fast it grows and whether I could keep it contained in that space? 

Also, given it’s so tiny, would I be better growing it on for a year first, or would it be ok planted right out, maybe using some annual fillers around until it gets big enough to not look totally lost?

I don’t think it’s a hugely common lilac, but I am hoping someone can offer some advice!

Lizzie27

That's odd @Nollie, my RHS book doesn't list it - has it been renamed recently do you know? Syringa are usually quite vigorous and can take quite a bit of hard pruning so I guess your smaller space might be okay. As it's so tiny, I would be inclined to keep it in a pot (I think you said your winters can be severe?) and then pot it on in the spring if it needs it. I believe you can cut the flowered shoots out completely each year, which would help to keep it compact but of course your particular variety might be different. 
I presume you've already done some internet research on that variety? Obelixx or Dove might know it better.  Sorry I can't help much.

Liriodendron

I grew Syringa protolaciniata 'Kabul' in the sunniest part of my Yorkshire garden - another cut-leaved lilac, maybe closely related to yours - I think it was formerly x laciniata too, and now it seems to be re-named S. afghanica... confusing.  Anyway, it looks very similar to S.x laciniata.  It was very shy flowering for me - just not enough sun in my garden, I think - though the leaves were gorgeous... it was slower growing than my ordinary lilac, and reached around 5 feet in maybe 7 years.  I didn't prune it much.  But I think it was struggling really, and might have grown faster if it liked me more!  It died from waterlogging one particularly wet winter.

So... I'm not much help either, sorry.  But I think I agree with Lizzie about keeping it in its pot over winter while it's so small.

Nollie

Hi @Lizzie27 and @Liriodendron, thanks for your input.

It’s variously described as cut leaf lilac, S. Persica x Laciniata and S. x Laciniata.

I did some initial research, but, as usual, lots of vague and conflicting info on the web. Some say it gets to 8x8ft and suckers, others that it can be kept to a 3ft. Some sites say growth rate is ‘average’ but average for lilac or average in general and what that means in either case...

I guess it does just depend on growing conditions, but probably likely to get big here. I have no idea how controllable or otherwise if I plant in the ground (in a new, mainly rose bed) where it might be happier, but I might be setting myself up for a battle to control it.

I think your both right and I need to keep it in a pot first, given it’s so small at the moment. Winters can get down to -8 here.