Choose the Right Mandarin Variety for Your Region
The most important decision you’ll make when growing mandarins is choosing a variety suitable for your climate. The three main types are Satsuma, Clementine, and Orlando. Satsuma mandarins, also known as Citrus unshiu, thrive in cold climates and are one of the most frost-tolerant citrus fruits, enduring temperatures as low as 15 to 20°F without damageWikipedia. Clementinesare a hybrid of tangerines and sweet oranges that grow best in Mediterranean climates with warm summers and mild winters. Orlando tangelos, a cross between tangerines and grapefruit, require long, hot summers and do well in the citrus belt of central Florida.
For home gardeners in cooler regions, Satsuma mandarins are usually the best choice, as Clementine and Orlando mandarins typically yield poor results and the fruit fails to develop its characteristic sweetness. In warmer regions, Clementines and Orlandos will produce an abundance of deliciously sweet fruit. With the wide variety of mandarins available today, there is likely one well-suited to your area that will reward you with a successful harvest.
Provide Optimal Growing Conditions
Mandarins require specific conditions to produce sweet, juicy fruit. The key factors for successful mandarin growth are:
Sunlight: Mandarins need full sun for at least 6 to 8 hours per day. Plant trees in an area clear of shade and tall buildings that could block the sun.
Temperature: Mandarins grow in tropical and subtropical climates. Most varieties can tolerate temperatures as low as 25 to 30°F.
• During the growing season, daytime temperatures should range from 65 to 95°F and nighttime temps should not drop below 50°F.
• For fruit development, daytime highs of 80 to 95°F and nighttime lows above 60°F are ideal.
Humidity: Mandarins prefer humid conditions, around 60 to 70% relative humidity. Low humidity can cause leaf and fruit drop. Mist trees during dry weather or use a humidifier.
Soil: Mandarins require fertile, well-drained, sandy loam soil with a slightly acidic pH between 6 and 7.
• Soil should be at least 2 to 3 feet deep to allow proper root development.
• Add compost or manure to provide nutrients, especially nitrogen for foliage growth.
Drainage: Mandarins cannot tolerate standing water and will suffer from root rot. Plant on a slope or raised bed and install drains if necessary.
Nutrients: Fertilize mandarins during the growing season. Use a balanced, citrus-specific fertilizer with equal parts nitrogen, phosphorus, and potassium, such as 8-8-8.
• For mature trees, apply 1/2 to 1 pound per inch of trunk diameter, split into 3 or 4 applications.
• Increase nitrogen in the first spring application to promote new shoot growth. Reduce nitrogen in late summer fertilizer to harden growth before dormancy.
Mandarins grown under optimal conditions will produce abundant, flavorful fruit for many years. Be diligent in providing the necessities to keep your tree happy and healthy.
Plant Your Mandarin Tree in the Right Spot
Choosing an optimal location is one of the most critical factors when planting a mandarin tree. The best spot has:
Full sun: Select an area that receives direct sunlight for at least 6 hours per day, preferably 8 hours or more. Partial shade will result in poor fruit production.
Protection from wind: Plant mandarins in a sheltered area away from strong winds which can damage branches, blow fruit from the tree, and dry leaves and soil. Use windbreaks such as fences or hedges if necessary.
Well-drained soil: Mandarins cannot tolerate standing water and will suffer from root rot if overwatered. Choose a site with sandy, loamy soil and plant on a slope or raised mound if drainage is poor.
Enough space: Mandarin trees can reach 15 to 20 feet tall at maturity, so space trees at least 15 to 20 feet apart. Closer spacing will reduce productivity due to competition for sunlight and soil nutrients.
Easy access: Select a spot that allows easy access to the tree for pollination, pruning, pest control, harvesting, and more. Do not plant mandarins in inaccessible corners of the garden or yard.
Once you have chosen a suitable location, prepare the site before planting:
• Dig a hole at least 2 to 3 times the size of the root ball.
• Mix the removed soil with compost or peat moss and fill in around the roots when planting. Do not add fertilizer at this time.
• Water thoroughly after planting and apply mulch 3 to 4 inches deep in a ring around the base of the trunk.
• Allow the soil to dry slightly between waterings, then water regularly for the first few years as the tree establishes. Never let the soil dry out completely.
By carefully selecting an optimal site and properly preparing the location, you will set your mandarin tree up for healthy growth and successful harvests. With the right planting spot and conditions, mandarins can become long-lived, productive trees in the garden.
Watering and Fertilizing Your Mandarin Tree
Mandarins require consistent moisture and regular feeding to produce high yields of sweet fruit.
Watering: Water newly planted mandarins thoroughly until the soil is saturated. For mature trees, follow this general guide:
• During fruit development and the growing season, water when the top inch of soil is dry, applying about 1 inch of water per week including rain. Soak the entire root zone.
• After harvest and through dormancy in winter, reduce watering frequency to allow the top few inches of soil to dry before watering again. Never let the soil dry out completely.
• Monitor your tree for signs of overwatering (leaf drop, root rot) or underwatering (leaf wilt) and adjust the watering schedule.
Fertilizing: Fertilize mandarins regularly during the growing season. Use a balanced, citrus-specific fertilizer with equal parts nitrogen, phosphorus, and potassium, such as 8-8-8.
• For mature trees, apply 1/2 to 1 pound of fertilizer per inch of trunk diameter, split into 3-4 applications from March to September. Increase the amount of nitrogen in early spring applications to promote new growth.
• Never fertilize after September to allow trees to harden off for dormancy. Late feeding can promote new, tender growth that is easily damaged by frost.
• Minor elements such as magnesium and manganese may need to be supplemented in some areas. Have your soil tested and consult an extension service for recommendations.
• Organic fertilizers such as compost, manure, and bone meal are also excellent for mandarins when applied properly. They provide slow-release nutrition and help improve soil structure.
With consistent moisture, regular fertilizer, and close monitoring, your mandarin tree will thrive and produce abundant harvests of sweet, juicy fruit for years to come.
Pruning and Harvesting Your Mandarin Tree
Pruning and harvesting mandarins at the proper time and technique is key to maintaining tree health and producing high quality fruit.
Pruning: Prune mandarins to maintain their shape, improve structure, and promote new productive wood.
• Prune young trees to one central leader and remove any criss-crossing branches. Prune side shoots to about 1/3 their length.
• Mature trees require little pruning. Remove any dead or crossing branches. Thin crowded branches and narrow the canopy to allow sunlight to reach the center.
• Avoid heavy pruning which can reduce yields for several years. Never remove more than 1/4 of the branches at a time.
• The ideal time for pruning is just before significant spring growth and after imminent danger of frost has passed.
Harvesting: Pick mandarins when fully ripe for the best flavor and sweetness. Fruit is generally mature 7-9 months after flowering. Look for these indicators:
• Color: The rind turns completely orange and develops a slightly glossy sheen.
• Softness: Gently squeeze the fruit. It should have slight softness without feeling mushy. Fruit that is still hard will not ripen properly off the tree.
• Ground color: The rind at the base of the stem turns from green to yellow-orange.
• Blemish-free: Check for unblemished, undamaged skin. Injury or rot shortens shelf life.
• Easily detached: Mature fruit slips easily off the branch when gently tugged. It does not require cutting.
• Brix level: Use a refractometer to measure the sugar content, which should be 9 Brix or higher.
Once harvested, mandarins will last 2-3 weeks when stored at room temperature. Enjoy your homegrown mandarins! With regular pruning and proper harvesting techniques, your mandarin tree will continue producing bumper crops of delicious fruit each year.
Preventing and Treating Common Mandarin Tree Diseases
Mandarin trees can be affected by several diseases and disorders that reduce tree health and fruit production. Prevention and early treatment are key.
Citrus greening disease: Spread by the Asian citrus psyllid (ACP), this bacterial disease causes mottled yellow leaves, misshapen bitter fruit and tree decline. Remove and treat ACP. Use certified clean nursery stock.
Alternaria brown spot: This fungal disease causes brown spots on leaves and stems. Leaves drop, weakening the tree. Copper sprays treat and prevent onset.
Citrus canker: Bacterial disease causing corky spots on leaves, fruit and stems. Leads to defoliation and crop loss. Copper and Certain® sprays or removal of diseased plant parts prevent spread.
Spider mites: These tiny spiders suck sap and chlorophyll from leaves, causing stippling and bronzing. Spray with predatory mite predators or organic insecticidal oils. Increase humidity.
Scale insects: Armored or soft scale insects attack leaves and stems. They secret honeydew, attracting ants and sooty mold. Apply horticultural oil or insecticidal soap sprays and increase natural predators like ladybugs.
Nutrient deficiencies: Lack of certain nutrients like nitrogen, iron or manganese cause leaves to turn pale or yellow. Have your soil tested and correct deficiencies with fertilizers or soil amendments.
Sunburn: Mandarin fruit exposed to too much direct sunlight develops a pale, bleached rind. Paint trees or provide shade cloth to protect developing fruit. Pick fruit slightly early in hot climates.
Wind damage: Strong winds can damage branches, blow developing fruit from the tree and dry leaves. Plant in a sheltered location and use windbreaks for protection.
The key to controlling diseases and disorders in mandarin trees is prevention through optimal planting, care, and sanitation. Closely monitor trees for signs of problems. Apply organic or conventional sprays at the first signs, or remove affected plant parts for small outbreaks. An integrated approach using cultural, biological and chemical means will keep damage and losses to a minimum.