Question
Hello, I have bought a house in Santa Monica, CA with 2 mature pink multi petal Camellias about 8-9 feet tall. They both have already bloomed profusely. They are located against a wall facing east sun. Although they both look healthy with shiny leaves but the leaves are slightly dusty looking with a brownish tinge. I am wondering if they are sick. A neighbor told me that I need to feed them. Is there such a thing as camellia food? If so how much and how often they need to be fed?

Answer
It sounds like your plants are lacking two key nutrients; iron and phosphorus.

As with all flowers, you want to use a fertilizer high in phosphorus and low in nitrogen. The ideal NPK ratio is 5-20-10 with the first number representing the percentage of nitrogen; the second number the percentage of phosphorus; and the third number the percentage of potassium.  

Just as a FYI, nitrogen promotes lush foliage at the expense of blooming. Phosphorus is the primary nutrient for flowering and fruit size on trees and vegetable plants. Potassium builds a strong root system and aids the plant in the absorption of nutrients.  

I would stay with a reputable water-soluble brand such as Miracle-Gro or Peter's, but there are many other great varieties that are sold in garden centers and nurseries. These products also have a high concentration of iron, a necessary nutrient for foliage and disease resistance. Avoid generic brands as I have found they lack the potency needed for strong growth and production.

Finally, apply the product according to the prescribed dilution rate on the package, usually once every 10 days starting 2 weeks after transplanting.   

Also, and most importantly, be sure to amend the soil with organic matter such as peat, compost, and aged manure. These materials will provide a constant source of nutrients, balance the ph level of the soil, and improve drainage. I have also found that plants grown in organic soil are much more resistant to disease and pests.  

I hope this answered your question. Please write again if I can ever be of assistance.  

Regards,  

Mike