Flowerdale Nursery & Landscaping
Citrus

 Citrus are native to areas of Southeast Asia, India & Australia. Citrus have become one of the most popular types of fruit grown widely in subtropical climates worldwide. Most (if not all) citrus trees grown for fruit are grafted. Many are grafted onto a rootstock which is dwarfing. A dwarfing rootstock prevents the canopy of the tree from growing large. Also citrus rootstocks that are resistant to disease or poor soil are frequently chosen. Care must  be taken to quickly remove any foliage or branches that sprout below the graft union (the place where the Upper portion of the plant is grafted onto the lower portion).

What Citrus Like

Exposure:  Citrus demand full sun. In order to produce good quality fruit, citrus need at least four hours of direct sunlight each day. Citrus are tolerant of windy & exposed conditions as long as the temperatures do not fall much below 25*.  Citrus can be grown in coastal areas but they do not tolerate salt laden air well. Citrus grow well in Southern California in USDA zones 9 & 10 as well as Sunset zones 18 through 24.

Soil:  Citrus are remarkably tolerant of many soil types & can be grown in relatively poor soils.  Ideally, citrus grow best in loamy clay soils with adequate drainage, but do poorly in very sandy or saline soils.  As with all fruit trees the addition of organic compost to the soil improves the quantity & quality of the fruit. In containers citrus grow well in a “cactus mix” type potting soil that provides adequate drainage.

Irrigation:  Citrus are remarkably drought tolerant fruit trees. In fact one of the most common problems associated with growing citrus worldwide is caused from too much water. The trees have a deep root system & waxy heat resistant foliage. In most of Orange County established citrus trees need watering only once to three times a month! (March through October).  In the winter, water once a month only if rains fail.  Irrigation must deeply soak the ground. Citrus growing in containers will need much more water than those in the ground.

Diet:  Citrus trees are evergreen & grow year round. Feeding citrus trees once a season (or once every three months) provides evenly spaced feedings that will sustain growth year round. Citrus trees in the ground should be fertilized with organic granular fertilizers.  We recommend Dr. Earth Organic Fruit Tree Fertilizer.  Citrus trees grown in containers require much more fertilizer than those in the ground.  Fertilize citrus in containers once a month with a liquid or water soluble fertilizer. Liquid fertilizers with fish emulsion work well, Black Gold Liquid fertilizer is recommended. Adding a layer of organic compost once a year as mulch (even in containers) helps improve the fertility of the soil. Citrus are prone to iron & nitrogen deficiency in our native soils. Citrus also crave micronutrients so products with Kelp, Fish Emulsion, & Humic Acid work well.

Pruning: Citrus benefit from pruning, when correctly done plants are hardy, less prone to disease, & produce quality fruit. Citrus must be trained so that they conform to an architecture that promotes health & vigor. Only prune citrus when the fruit are present. The window is short extending just several weeks after fruit has ripened. In short you want to prune the plant before it starts to flower again. This will prevent you “pruning away” the next crop of fruit. Two methods of shaping citrus are as follows:

1.       Training as a Small Tree (10’ + high & wide) - This is the method that works best with most citrus. In this strategy we want a small tree with an open branch form with a dense canopy of foliage but an uncluttered crown of branches. Remove all dead & crossing branches whenever noticed. Protect the graft union & remove any suckers that sprout below it. Shape trees with selective pruning once a season (once every three months).

2.      Training as a Shrub (less than 10’ high & wide)-This works well for citrus that have to be grown in small spaces or in containers. In this strategy we choose to make a shrub. Short multiple trunks are optimal, as well as a dense canopy with an open network of branches. Increasing air circulation helps in controlling pest & diseases. 

Always prune with clean cuts & clean tools. To avoid the spread of diseases disinfect tools after working on your plants. Use a simple weak dilution of bleach in water or wipe tools with alcohol.

Harvesting:  Harvest citrus fruit when they are in full color & are just slightly soft. Do not let fruit stay on the plant too long, it causes citrus re-greening & severely decreases the quality of the fruit & limits future production. The fruit should detach easily from the plant when ripe.

Varieties

Oranges:

·         Valencia – makes the best juice

·         Navel (Late Lane Navel is a late harvesting variety) most popular orange

·         Cara Cara Orange – pink flesh super sweet

·         Moro Blood Orange- red flesh berrylike flavor

Lemons:

·         Eureka- good for containers

·         Improved Meyer - very juicy

 

Limes:

·         Bearss- a Californian variety

·         Sweet Lime- makes great juice

·         Mexican (Key) Lime- bartenders lime

Grapefruit:

·         Oroblanco- white flesh

·         Ruby- pink flesh

Tangerines:

·         Dancy- heavy producer

·         Clementine- small choice fruit

·         Algerian- hardy plants

Mandarin:

·         Honey- great flavor

·         Satsuma- high quality

Tangelo:

·         Minneola- (cross between a pummelo & tangerine) great flavor

Pummelos:

·         Chandler-huge fruit with sweet flesh

Kumquat:

·         Nagami- sweet rind tart flesh

·         Meiwa- superior variety