Hello....I am growing several in my greenhouse which I keep at 40 degrees or above in the winter both for the proteas and for some vireyas (tropical rhodies). I put them outside in their pots last summer and have had them out again as so as the nights didn't go below 45 although I did protect them from heavy rain until we got to really warm weather. I have 4 proteas: P. cynaroides, P.burchelli, Leucospermum cordifolium, Leucadendron uliginosum all started from seed from a starter pack from Finebushpeople.co.za I have a couple of books on growing proteas and they say that P.cynaroides (King Protea) is the best suited for greenhouse growing because it tolerates a wider range of moisture. I would think they could be grown indoors but they do get very large. Here in the pacific northwest there are a few leucodedrons which are grown outdoors in some of the more protected microclimates around Portland and probably also around Puget Sound. Happy protea growing. jwww

I don't know anything about King Proteas but many plants in the Proteaceae family are susceptible to Phytophthora pathogens. This could explain why one plant is thriving in the same conditions that the other isn't. This soil borne pathogen might have got in around one plant but not the other. It could have been from soil or mulch brought in. That could include soil from another plant that was planted nearby. This is only a guess, but worth looking into. One of your local nurseries might have more information about this.

There are some good books on Protea, to which Leucadendron belongs, but these are pretty expensive books. Does anyone know of a good plant book with a more general coverage that has extensive photographic coverage of Leucadendron? In general, how fast will Leucadendron's grow? Most references online say it needs a fast-draining soil. If I plant in California native clay soil, but in mounds above the water line, should that be sufficient for drainage? Some sample Leucadendron photos are below. This video on a Protea garden in Australia also shows the remarkable flowers and diversity of Protea.

For a successful, long-term container planting, you need to use a proper container/potting soil. "sandy loam" or any other garden soil will not provide adequate drainage or porosity in a container. I grow grevillea, which also shares a phosphorus sensitivity common to Australia native plants, in the same bark-based 5-1-1 mix I use on almost all of my containerized plants. A friend who owns a local, mostly mail order nursery that focuses on hardy plants originating from the Southern Hemisphere and includes many P sensitive species uses a similar mix.