|I have four dwarf fruit trees, lemon, lime, orange and grapefruit. At what rate should these trees be watered in the summer months and for how long?
|Citrus watering depends on how long the trees have been in the ground, i.e., newly planted vs. established. Here's some info on watering effectively in the low desert: Desert soil and water both contain salts, which can accumulate in the root zone over time. This salt buildup forms where the water stops penetrating. If you ?sprinkle? plants lightly and frequently, salts will build up in the top layers of soil and damage or kill your plant. Deep watering?or leaching?prevents this by flushing the salts past the root zone.
Roots also need oxygen to survive and soil that is continually wet doesn?t provide it. Use a soil probe (any long, pointed piece of metal or wood to poke into the soil) to check how far water has penetrated. The probe moves easily through moist soil, but stops when it hits hard dry soil. There are numerous variables involved for watering schedules, such as type of soil, how fast or slow it drains, sun and wind exposure at your site, temperature, age and condition of the plants and much more. Use the information above to determine how moist the soil is before automatically applying more water.
As a tree grows, its new roots tips, where nutrients are being absorbed, spread out laterally. If you are watering only within a few-foot area at the base of the tree, it's not really being watered effectively. Expand your watering zone out PAST the tree's canopy. As the tree grows, continue expanding that water zone. If you have an irrigation system, you need to move the emitters out. If you use a hose, just drag it out further. In any case, water slowly and deeply to ensure water penetration and to leach salts below the root zone. There are numerous variables involved for watering schedules, such as type of soil, how fast or slow it drains, sun and wind exposure at your site, temperature, age and condition of the plants and much more. It?s important to learn the specific needs of your landscape, both for its health and your water bill. For newly planted trees, water should reach about 2 feet deep, expanding to 3 feet as it matures. You probably need to water 5-7 days in summer until the root system establishes, or keep the soil consistently moist for a month or so. Then gradually taper off as weather cools to every 2-3 weeks. It's essential that you allow your drip system to run long enough for water to penetrate the appropriate depth. Depending on the size emitters, soil type, etc. this might take several hours.
Desert Landscaping for Beginners, ISBN 0-9651987-3-1, Arizona Master Gardener Press has an excellent chapter on citrus growing, including watering and fertilizing charts based on the tree's age.