a wide divergence between potting media ... and native soil can be very problematic ...

in my sand.. peat based media is sucked so dry.. that it will never re-wetten .. causing dry rot in the plant...

that said.. i never really recommend amending soil.. other than hard core clay ....

that and the fact .. that 25 gallons of media is way too expensive ... so i would reuse it for a while.. after a few years.. . it might need to be replaced ...

i had always had a hard time with soil in a pot.. you can not 'control' the variables ... like how water moves thru it ... air pockets for the roots.. etc ... also ... if you have many pots.. its good to have similar media thru all of them.. so they dry at nearly the same rates ....

with media.. you are paying for the engineering that went into how it moves things thru the pot.. and well worth it.. IMHO ....

ken

ps: ... i hope you mean you will be unpotting adn planting the hydrenga at proper planting time in a month or so ...

I use native soil in all my pots. I lighten it - mix in some peat-based potting mix, about 50/50 ratio.

If I'm potting up something temporarily (i.e. won't have a permanent home in the pot), I use all native soil.

I never use native soil or a combination containing native soil in a pot. You're on the right track with your bark based mix and you say the shrub is happy...why change. One suggestion for the approximate timeline for repotting/replacing the bark based type media for hydrangea in large containers is roughly every three years (Hinkley, former Heronswood).

I only use bagged potting soil for pots.

Those posters that refer to the differences involved in growing plants in containers versus inground and the need for different considerations are right on the money! What works well inground fails rapidly in a closed and biologically inactive environment like a container. Most of it has to do with the movement/retention of water and adequate porosity or airspace but a good portion also has to do with reduced or missing soil biology and therefore nutrient delivery. Most acceptable potting 'soils' are not soil at all but mixes that include bark, peat, coir and other textural, non-organic components. Virtually any container gardening resource will tell you to avoid using any garden soil in containers and even to minimize any compost as an ingredient - too heavy, too uniform, too able to compact and too slow to drain.

It may help to take a peruse through the attached link, which is a fixture on the container gardening forum. Extremely well-written by one of the most knowledgeable GW members I've encountered (also one of the most generous and helpful). It is now in its eleventh posting, indicating how much activity (several thousand responses) this particular thread has generated. You can't get better container gardening info out of any book.

Here is a link that might be useful: Container soils - all you need to know :-)

Well, yea, I know - but using native soil works for me, what can I say?

Case in point: This Rodgersia has been in this pot in part native soil (somewhere around 50:50 mix) for something like 8 or so years already, have never changed out the soil (because I *dread* having to re-pot that monster). How can anyone tell me using native soil isn't working in my case?

{{gwi:194282}}

Posted some pics of potted annuals and a standard-form hydrangea today in another thread - I think they look pretty darn good, but one can take a look and judge the results for oneself.

Two issues I have with soil-less medium: (a) dries out at the drop of a hat - not only do I very, very strongly dislike watering chores, I don't have time to be out there watering all my potted plants every day; mixing native soil in with it retains moisture longer, and (b) it gets expensive if one has a lot of potted plantings that are re-planted every year (e.g. annuals).

The point I'm trying to make is while, yes, conventional advice is to use 100% soil-less potting material, it may be worthwhile to try the unconventional route and see if it works - hey, why not? :0)