Site Selection (Environmental and Soil Requirements) for Lemon and Citrus Orchards
- Soil Characteristics
Like most citrus trees, lemon trees require deep, well-draining soil, ideally with a sandy loam texture, to prevent root diseases and waterlogging.
- Soil pH: The ideal pH for citrus orchards is between 5.5 and 7.5, as extreme acidity or alkalinity can limit nutrient uptake. However, citrus trees can tolerate a pH ranging from 4 to 8.5.
- Soil Texture: Citrus trees thrive in deep, (light) sandy loams but can tolerate a range of soils if drainage is adequate. Heavy clay soils may need deep tilling and organic amendments to improve aeration and drainage.
- Drainage Testing: To ensure soil is well-drained, you can dig a 30 cm (1 foot) deep hole, fill it with water, and observe drainage. The soil should absorb water within 24 hours.
Adding organic matter such as compost enriches soil structure and helps retain moisture while preventing compaction, which is essential for young citrus trees establishing their root systems.
- Climate and Temperature Requirements
Lemon trees thrive in regions with mild winters and warm summers. More specifically:
- Temperature: Optimal temperatures for lemon growth range from 13 to 38°C (55°F to 100°F). A soil temperature of 25°C (77°F) is considered optimal for root growth, while a temperature of above 20°C (68°F) is necessary for successful transplanting and plant establishment. In frost-prone areas, windbreaks or planting on slightly elevated ground can help protect trees from cold air pockets. Lemon trees are sensitive to frost. More specifically, freezing temperatures of:
- -1.7-2.2°C (29-31°F) can damage the flowers and fruits
- -4.4 to -5.6°C (22–24°F) can lead to defoliation
- -6.7°C (20°F) can cause severe wood damage
- Sunlight: Citrus trees need full sun exposure, ideally 8 hours or more daily. A north-south row orientation maximizes sunlight, which supports photosynthesis, flowering, and fruit development.
- Humidity: Citrus trees prefer semi-arid to subtropical climates. High humidity can increase disease susceptibility, particularly in dense orchards with poor air circulation. Other effects could be the less bright color of the fruit and the the fruit peel texture to be coarser or more puffy. Spacing trees further apart and promoting air circulation can reduce disease risks in areas with high humidity.
- Wind: Strong winds can harm lemon trees. Establishing natural or artificial windbreaks around the orchard helps shield young trees and retain heat in colder months. Windbreaks can be created using hedges, rows of trees, or even fencing.
- Field topography and Slope
Citrus orchards generally perform best on land with a slight slope, which aids water drainage and helps protect against frost by allowing cold air to flow downhill. Ideal slopes range between 2-4%. You shall avoid steep areas (>20° slopes) that may lead to erosion and make maintenance difficult. Sites on south-facing slopes are often preferable, as they capture more sunlight and avoid cold air settling, which is beneficial in frost-prone regions.
- Water Supply and Quality
Quality water is essential for citrus orchards, particularly during dry periods and fruit development stages. Lemon trees can be successfully established in soils with 1,280 ppm. Excess salinity in irrigation water can harm the plants by causing leaf burn and reducing productivity. Regular testing of water quality can help ensure the salinity levels are manageable.
Soil Preparation for Citrus Orchards
Proper soil preparation is a key factor in successful citrus tree establishment. The preparation should focus on creating a nutrient-rich, well-drained environment with deep, loose soil that supports root growth and prevents waterlogging.
The first step a grower should take is to perform a soil analysis to gain more information about the soil. These data will be used to make informed decisions and adjust practices like irrigation and fertilization. If the soil pH is too low (acidic), the farmer is advised to add lime to raise it. On the contrary, if it is too high (alkaline), the grower can add sulfur to lower it to optimum levels. A balanced pH helps ensure the availability of essential nutrients. In case the soil analysis shows nutrient deficiencies, the grower can add the missing nutrients or/and apply balanced fertilizers. Nutrients like nitrogen, phosphorus, and potassium are critical. Phosphorus supports root development, while nitrogen promotes vegetative growth. Incorporating compost or manure can also effectively enrich the soil with the nutrients needed for lemon tree growth while improving soil health (soil fertility, retaining moisture, and supporting beneficial microorganisms).
If the field is contaminated with soil-borne diseases, pests, or nematodes, the growers are advised to apply soil solarization to clean the field before planting the young trees. You should avoid establishing a lemon orchard in areas with known problems such as Armillaria and Bacterial blast (Pseudomonas syringae). Additionally, vegetation, rocks, and debris must be removed from the planting area. Weeds compete with young citrus trees for nutrients and water, so effective weed control (cultural, mechanical or/and chemical) is essential before planting.
When all previous preparations have been made, the farmer can perform deep plowing 30-45 cm (12-18 inches) and subsoiling to help break up compacted soil layers, improving water infiltration and root expansion. This is particularly beneficial in clay soils where compaction can hinder root growth and cause water retention issues. You should also consider installing a drainage system (like ditches) or planting raised beds to prevent waterlogging in areas prone to poor drainage, which can lead to root diseases (remember, lemon trees are sensitive to waterlogging).
Finally, if we choose to have irrigation in our orchard, we can establish an irrigation system (subsurface drip irrigation). This can ensure consistent water availability for young trees, promoting healthy establishment and reducing the risk of foliar fungal diseases and water stress.
Conclusion
Successful citrus orchard establishment depends on selecting the right site, preparing the soil, and maintaining optimal conditions for tree health and productivity. By carefully considering soil characteristics, climate suitability, water quality, and implementing structured soil preparation techniques, growers lay the foundation for a productive citrus orchard. With continued care, regular monitoring, and appropriate orchard management, these trees can yield high-quality fruits for years to come.
References
https://aggie-hort.tamu.edu/citrus/L2306.htm
https://yardandgarden.extension.iastate.edu/article/1996/4-5-1996/plnttree.html
Further reading
15 Interesting Facts about Lemon Trees
Information, Uses, Health Benefits, and Nutritional Value of Lemons
The most Popular Lemon Tree Varieties
How to Cultivate Lemon Trees Commercially
Site Selection and Soil Preparation for Planting a Lemon Orchard
Complete Guide to Planting Lemon Trees
Lemon Tree Propagation and Pollination
Lemon Tree Pruning for Optimal Growth and Yield
Understanding the Water Needs of Lemon and Citrus Trees
Nutrient needs and Fertilization of Lemon trees
Pest and Weed Management in Lemon Orchards
Important Virus Diseases in Citrus trees
Important Citrus Diseases caused by Fungi
