I bought a very nice Adenanthos sericeus (Woolly Bush) that will grow into a large pot. Since this is a plant that, similar to Protea, does not like phosphorus, I want to take care to study the soil mix that I will use. The Protea soil I have seen recommended is the formula:

• 2 parts peat
• 2 parts sand
• 1 part 1/4 inch rock

I have on hand a lot of the succulent soil named gritty mix, which is the formula:

• 1 part 1/4 inch rock
• 1 part turface hard-fired clay
• 1 part redwood compost

That succulent soil is likely much drier. Can Woolly Bush handle a drier soil, or would it prefer a well-drained soil that stays more moist?

In the gritty mix, I occasionally substitute redwood compost with potting soil, which surely does have some phosphorus in it. Is that small amount of added phosphorus enough to traumatize this plant?