In 1998, at the San Marcos Growers Field Day, nurseryman and protea specialist Dennis Perry gave a talk on plants in the Protea family that are good for southern California Gardens. His talk, then titled, "Growing Protea in California Gardens" covered the best cultivars and how best to grow them given our climate, soil and water limitations. Dennis made a handout for his talk. Much of the information below is from this handout but in 2003 Dennis edited this document to include additional information he has learned since and new cultivars that have become available in the subsequent 5 years. We have also linked to our database any of the plants that we continue to grow. Click on these plant names for more information and images.

Genera to be discussed and major desirable characteristics

Banksia – Exotic flowers and foliage
Leucadendron – Foliage form and color (i.e. bracts)
Leucospermum – Pincushion flowers
Protea – Exotic flowers

Genera in the Proteaceae that San Marcos Growers lists but was not discussed in this talk

Adenanthos
Grevillea
Hakea
Isopogon
Stenocarpus

Garden Maintenance

            Drainage – MORE IS BETTER
            pH – ACID IS BETTER
            Nutrition – SECONDARY & MICRONUTRIENTS
            Pruning – PRUNE, PRUNE, PRUNE
            Mulch – MULCH, MULCH, MULCH!!!
            Temperatures - Requirements vary:
                        Generally warm days & cool nights best
                        Only a few selections survive below 20 degrees Fahrenheit
            Containers – GREAT!
                        Create Drainage using Perlite & Scoria
                        Use Stable Potting Mix
                        Mineral soils
                        Long Term Organic Components
                                    Peat & Bark
                        pH - 4.5 to 5.5
                                    Add Sulfur to lower pH
                        Nutrition N,K no P! Secondary Nutrients & Micronutrients are most important

Future Trends

            Selections
            Grafting

pH, Total Alkalinity, Lime & How Much Sulfur Should I Use?

1.      Get a soil test!

2.     How much Lime (calcium carbonate & bicarbonate) is there in addition to actual pH of the soil?

3.      Usually some Lime is present, so the acid amendment, Sulfur, must:
a)     overcome the Lime in the soil to lower the pH
b)     act on the soil to lower the pH

Without Lime it takes the following, in pounds of Soil Sulfur, to effect these changes in a loam soil to a depth of 12 inches:

                                   pH                                         Soil Sulfur

                                   8.5>6.5                           11.5     #s/100 ft²
                                   8.0>6.5                             7.0     #s/100 ft²
                                   7.5>6.5                             3.7     #s/100 ft²
                                   7.0>6.5                              .7      #s/100 ft²

Gypsum should be avoided unless Calcium is not present.  Calcium along with Phosphorus can be detrimental at even ‘normal’ levels to proteas.  

Notes on Nutrition