Spring Home and Garden Show All About Citrus Fertilizing Citrus Nitrogen - Ammonium nitrate or urea Non-Bearing 1 to 2-year old trees 1 Tbsp. once every 3-4 weeks 2 Tbsp. 4 x yearly Total: 1/10 lb. per year Older Trees 3-yr old tree 1/4 lb. per year 4-year old tree 1/2 lb. per year mature tree 1 lb. actual nitrogen per year To calculate the amount of nitrogen in a fertilizer: example: 21:5:10 21% nitrogen, 5 % phosphorus, 10 % potassium Internet Resources For answers to all pest management gardening questions, Google UC Davis IPM and you'll get to their website: http://www.ipm.ucdavis.edu/ For descriptions of over one hundred varieties of citrus, Google UC Riverside Citrus Varieties to get to their website: http://www.citrusvariety.ucr.edu/citrus/index.html Recommended Citrus Varieties SUNSET MAGAZINE (web article) LANCE WALHEIM Blood Orange (citrus author & contributor to Sunset Publications) Freemont Tangerine Kishu, Page, Pixie and Gold Nugget Mandarins Japanese Yuzu Owari Satsuma Improved Meyer Lemon Mexican (Key) Lime Oro Blanco Grapefruit FRESNO COUNTY MASTER GARDENERS Oro Blanco Grapefruit Eureka Lemon, Improved Meyer Lemons Bearss, Kafir Limes Clementine, Satsuma, Tango Mandarin Oranges Cara Cara Navel, Moro Blood, Torocco Blood, Valencia, Washington Navel Oranges Page 1 MY FAVORITES ROCK CHRISTIANO Kishu Mandarin (citrus expert at Lindcove Research and Extension Cent Okitsu Wase Satsuma Sarawak Pumello Indio Mandarinquat Mato Buntan Pumello Cocktail Hybrid Pummelo Improved Seedless Meyer Lemon Key, Finger, Kieffer Lime Thornless Mexican Lime Improved Meyer Lemon Kishu Mandarin Torocco Blood, Cara Cara Navel Oranges Cara Cara Navel Orange Bearss Lime Bream Torocco Blood Orange Page 2 .