Citrus

Care & Maintenance

Citrus in desert climates needs deep, infrequent watering on a basin or drip system rather than frequent shallow irrigation. Water every 7 to 14 days in summer depending on tree size, and pull back significantly in winter. Fertilize three times a year in January, May, and August with a fertilizer that includes iron, manganese, and zinc, because the alkaline soils throughout the Southwest lock out these micronutrients and cause yellowing even when the tree is otherwise healthy.

Common Issues & Threats

• Iron chlorosis: New leaves turn yellow while the veins stay green, a classic sign that your alkaline soil is blocking iron uptake. Foliar sprays of chelated iron provide a quick fix, but soil acidification with sulfur is the longer-term solution.
• Citrus leafminer (Phyllocnistis citrella): A tiny moth whose larvae tunnel through new leaves, leaving silvery, squiggly trails and causing leaves to curl. It looks alarming but rarely kills the tree. Spinosad-based sprays on new flush growth are the most effective control.
• Asian citrus psyllid (Diaphorina citri): Small, brownish insects that feed on new growth and leave waxy white tubes of secretion. More importantly, they can carry citrus greening disease (HLB), which is fatal and has no cure. If you see psyllids, report them to your county extension office immediately because this is a regulated pest in many states.

Pruning Guide

The most important thing to know about citrus pruning is that the tree does most of its own structural work, and heavy pruning usually causes more problems than it solves. Remove any shoots that emerge below the graft union, which is the swollen knob near the base of the trunk, because those are rootstock suckers that will not produce edible fruit. Do any corrective pruning in late February after your last freeze risk but before the spring flush, and always leave enough canopy to shade the trunk, because exposed citrus bark sunburns easily.

Did You Know?

Here is what most people get wrong: they assume more water means more fruit, but citrus actually sets better crops when the tree experiences mild stress in late fall. Cutting back irrigation in October and November triggers the flowering response you see in late winter. Also, most residential citrus trees are grafted onto a different rootstock variety, which means if your tree ever dies back to the ground and resprouts, what grows back is not your Valencia orange, it is the rootstock, usually a thorny, bitter-fruited trifoliate orange.

Where Citrus Is Found

Citrus is common in 94 of the US communities we cover, across 1 climate regions.

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