Soil-less all the way. But why are you not planting in the ground. And as Ken has already admonished, these are simply not houseplants. They need to go through normal winter chilling and the whole bit. Maybe you explained that already and I missed it. But by far, the best place for these trees is in the ground somewhere.

+om

arent you in seattle or some such ... where are you ... refresh our memory in each post ...

a cactus mix is just about perfect ... very lose and airy ... perhaps cut 50% with regular media ...

wood chips on top is dressing.. not really relevant ... to your media mix

i found.. when i started calling the stuff in pots... MEDIA ..... then i quit confusing it with soil ... which is mother earth in my vernacular ...

ken

A lot of conifers, pines included are very susceptible to damping off as seedlings, especially when grown in a 'wet' mix. Best success I've had...a soil less seed starting media (2/3) with perlite (1/3).

Growing a conifer in a container, even on a temporary basis, does not necessarily translate into it being treated as a houseplant :-) And it's a pretty practical method for growing on seedlings or small starts before planting out into the landscape.

For best container growth, you want a very durable, fast draining potting mix. Growers typically use a bark based mix, something very textural. The cactus mix Ken referred to could work or look at recipes for Al's gritty mix (found on Container Gardening forum).

If you choose to make your own, look for composted bark fines (also small orchid bark or reptile bedding will work), add in granite or poultry grit, high fired clay (Turface) and pumice or perlite. No vermiculite!! And very little peat - no more than 15-20% of the mix.

Thanks guys for your comments to answer your questions I live in South west Uk and the why don't I plant them in to the growing is because till November 2016 this is my garden