Citrus Resouces | UC Master Gardeners of San Diego County

UC IPM Citrus Information

Panel 1 – Identify Pest Damage

Concept: Citrus trees have relatively few pest problems if they receive good care

Common pests: Pests that attack citrus include insects, mites, snails and rodents
Prevention: Check trees regularly to detect pests before serious injury occurs
Snails: Most active at night, use hand cultivation method, removing snails daily
Rust mites: No natural enemies, check UC pest management guidelines for citrus
Citrus leafminer: Healthy, mature trees are capable of combatting infestation.
Diaprepes Root Weevil: Poses a great threat to citrus & other crops; each life stage should be treated with appropriate pesticide. Refer to UC IPM for specifics
Asian Citrus Psyllid: Pest that acts as carrier for spreading ‘huanglongbing’ (HLB) a devastating disease of citrus trees; contact San Diego County Agriculture Department (Pest Detection) if suspected at (858) 614-7770

Panel 2 – Planting Citrus Trees

Concept: Choose healthy young trees and follow planting guidelines for best results

Purchase healthy looking plants from reputable nursery
Consider climate in your area to determine when to plant
Wind free location with full sun is desirable
Citrus can be planted in containers or directly in the ground
Allow enough space for tree to grow to mature size
Dig a hole wider than the root ball of the tree
No soil amendments are needed at planting time for most areas
Upper surface of tree ball should be about 1 inch above surrounding ground.
Gently tap loose soil around the root ball immediately, then fill in the rest of the hole with loose soil
Water the tree immediately after planting and keep the root ball moist until roots grow out into the surrounding soil
Timely irrigation is essential for proper tree growth, development and fruiting
As a rule of thumb, water when the top few inches of soil are dry, but the rest of the root zone is still moist

Panel 3 – Nutritional deficiencies

Concept: Successful fruit production requires an adequate supply of essential nutrients to trees
Primary nutrient is nitrogen; (N) phosphorus and potassium are not needed as often
In some areas other nutrients may be required
Young citrus trees (2 – 3 years old) should be fertilized adequately to encourage maximum early growth
A tablespoon of nitrogenTbearing fertilizer may be sprinkled every 3 or 4 weeks over root area of nonbearing trees.
As trees mature, more fertilizer is required to support healthy growth
For more specific information see: http://ucanr.edu/sites/VCMG/Planting_and_Care_of_Young_Citrus_Trees/
Visible sign of nitrogen deficiency – leaves turn pale green to yellow, especially in winter and spring with no evidence of mites present

Panel 4 – Keeping trees clean and healthy

Concept: Prevention is the most economical method of controlling citrus disease
Whenever possible, use mechanical control methods to combat pests
Remove diseased limbs and clean up any debris which may encourage pests
Dislodge pests with strong blasts of water or with soap or oil sprays
Strong blasts of water usually dislodge aphids
Soaps and oil sprays are effective against softTbodied insects and mites
Biological control methods may also be used; release natural enemies to combat pests
Chemicals should be used as a last resort