Native Plant Potting Mixes

[Pisgah]

For those of us on the other side of the planet who want to mimic australian commercial native potting mixes, what's in them?

I have a general idea, but specifics would be great.

Cheers...

[Alice]

AFAIK the common bagged ones are just like a normal general purpose potting mix (ie composted barkchip with little to no inorganic matter), but the fertiliser (usually slow release pellets like osmocote) is low P, and less or no synthetic wetting agent granules (such as polymethacrylate, "jelly blobs").

the soil over here is generally pretty poor quality, if you're planting acacias etc the from my experience they'll grow in just about anything, as long as its not too high in P. having said that, acacias are nowhere near as P intolerant as proteaceous natives, tho i wouldn't go dumping a heap of superphosphate on them just yet

[hairyplant]

I use a mix that has no added fertiliser for my natives, and if needed I add a native specific (low P) slow release later. Probably though, most potting mixes would be fine, except for, as is mentioned above, plants such as those in the proteaceae family. If your making your own, maybe just add less compost than you normally would for drought tolerant plants. Avoid mushroom compost.

[Pisgah]

Thanks everybody.

I live in an area with clay soils, so I'm thinking about mixing my dirt with composted pine bark for bedding areas. It seems I can keep using my regular potting soil, cut with coarse sand for my acacias in containers.

[Benzito]

I live in the Blue Mountains, NSW, which are filled with Acacias with goodness in them.

The soil around my area is pretty heavy clay-based, filled with sandstone-type rocks only one foot down. So, it's impossible to dig in, but does have a fair bit of sandy sh*t for drainage.

As Alice said, most Aussie soil is pretty poor quality.

[Pisgah]

Although my climate does not match Australian climactic zones, the soil here is acidic, old, clay-like and compacted. I think by breaking up the compacted nature of the soil with composted pine bark, I will create a reasonable bedding substrate for obtusifolia. In order to buffer temperatures, I am going to grow them under a cold frame with a block heater for the coldest nights.

I have been looking around for good organic, low phosphorous ferts here in the USA and have found kelp meal to be a reasonable candidate for acacia. I think it is 4-0-2, with lots of micronutes.

Another thing I am playing around with is crumbled charcoal (like is used in epiphytic orchid seedling substrate). Since many alpine acacias germinate post-fire, I would think charred vegetable matter would be present to some degree.

It's cold here right now, but I am juiced to figure out this acacia thing in my climate this growing season.

Cheers for the input!