Solutions For The Top Diseases & Pests Of Homegrown Citrus

Growing Citrus trees at home is a rewarding experience. Family and friends will love the fragrance and flavor of fresh, homegrown fruit.

Success requires regular monitoring for signs of pests or disease. The best time to deal with a problem is before it becomes a problem.

Many different pests and diseases can affect Citrus trees in various regions. When in doubt, check with your local Ag Extension Service.

For all product recommendations, always follow label directions for dosage and application to ensure safe and effective results.

• Top 10 Most Common Citrus Diseases and Pest Problems
• First Step For Citrus Health - Planting!
• Care & Maintenance - Keep Citrus Healthy!
• A Zesty Wrap-Up!

Top 10 Most Common Citrus Diseases and Pest Problems

• Phytophthora Root Rot - Often caused by poorly drained soil or overwatering. Dulling, yellowing, and leaf drop are early signs, and roots may become brown and mushy.
  • Solution: Reduce watering and improve drainage. Plant in an elevated berm (mounding soil 18-24 inches higher to raise the root system over soggy soil), amend heavy soils to improve drainage, and keep mulch a few inches away from the trunk.
• Scale - Includes Armored Scale and Soft Scale. Appears as small bumps on leaves and stems, often producing sticky honeydew and black sooty mold.
  • Solution: Wash off with water and wipe smaller trees. For larger trees, prune infested branches and spray with a Neem Oil Concentrate. Encourage Ladybugs to help naturally control them.
• Ants - Ants "farm" Scale and Aphid eggs on Citrus trees; however, their presence doesn't affect the tree directly. Their increased presence is a sign to look for their "flock".
  • Solution: Spray Fruit Tree Spray that contains Neem/Pyrethrin in early morning or late afternoon to keep ants out of the canopy and treat for the pests they're attracted to.
• Mites - Populations can explode in summer heat or indoors during fall. Signs include speckled or stippled leaves.
  • Solution: Keep the soil slightly dry and spray Neem Oil Concentrate at the first sign. Keep product on hand for quick treatment.
• Fungus Gnats - Tiny black insects that thrive in damp soil. This is more of a problem indoors.
  • Solution: Allow the soil to dry slightly and apply gnat soil treatments, a systemic, a diluted vinegar spray over the soil surface, or use RTU Spray for gnats to the soil surface.
• Rats and Squirrels - These pests can strip your crop overnight.
  • Solution: Spray or shake repellent granules around your garden, sheds, and home. Smaller trees can be covered in netting. Use traps or baits if needed.
• Citrus Leaf Miner - Small moth larvae that tunnel inside leaves, leaving silver squiggly trails.
  • Solution: Prune out affected leaves early and apply horticultural or neem oil during new growth flushes to discourage egg laying.
• Sooty Mold - A black, powdery fungus that grows on leaves due to honeydew from Scale, Aphids, or Whiteflies.
  • Solution: Control the pests causing honeydew, then wash leaves with mild soapy water or horticultural oil spray.
• Citrus Greening (HLB) - A serious bacterial disease spread by the Asian Citrus Psyllid. Causes yellow shoots, bitter lopsided fruit, and tree decline.
  • Solution: Prevention is critical! Only buy certified disease-free trees and remove infected trees immediately.
• Nutrient Deficiencies - Yellowing leaves, poor fruit quality, or slow growth often signal low nitrogen, iron, or magnesium.
  • Solution: Apply a Citrus-specific fertilizer with micronutrients. Keep soil pH at 6.0-7.0 and use chelated iron or magnesium sulfate as needed. For more details on how to fix Citrus leaf drop, check out our full guide.

First Step For Citrus Health - Planting!

Getting your Citrus tree off on the right foot is your top priority! This ensures you have a strong foundation, healthy root system, and the best conditions to guarantee the best Citrus health!

Best time: Plant in spring once nights stay above 45 to 50°F. In cooler zones, grow Citrus as a container dwarf fruit tree to move indoors before frost.

1) Choose the right spot or pot

• Sun: Full sun, 6-8 hours daily. A south-facing wall boosts heat and ripening.
• Soil: Well-drained and slightly acidic to neutral. Raised beds help in clay soils.
• Container: Use a pot with drainage holes. Start with 16-20 inches wide for young trees, size up as roots fill.

2) Prep the planting area or mix

• In-ground: Loosen soil 2-3 times the width of the root ball. Add compost, but avoid water-trapping holes.
• Container: Use quality potting mix with perlite or pine bark for drainage.

3) Plant correctly

• Set the tree at the same depth as in the nursery pot with the graft above the soil line.
• Backfill gently, water deeply, and mulch 2-3 inches thick but away from the trunk.

4) Acclimate and position

• Increase sun exposure gradually when moving plants outdoors.
• Indoors for winter: place in a bright south-facing window or use grow lights.

5) First 2 weeks after planting

• Keep soil evenly moist but not soggy using the finger test.
• Avoid fertilizing for 2-4 weeks to protect young roots.

Care & Maintenance - Keep Citrus Healthy!

Light and temperature

• Light: Full sun outdoors. Indoors, 6-8 hours of bright light daily.
• Temperature: Best between 55-85°F. Protect below 40°F with frost cloth.
• Humidity: Indoors, aim for 40-50% with a pebble tray or humidifier.

Watering

• Goal: Keep slightly on the dry side between waterings.
• Containers: Water thoroughly, then allow the top 1-2 inches to dry before rewatering.
• In-ground: Deep soakings with a soaker hose; increase in heat waves.

Feeding

• Fertilizer: Use Citrus-specific or balanced fruit tree fertilizer with micronutrients.
• Schedule: Start 4 weeks after planting. Feed lightly every 6-8 weeks, from spring to midsummer.
• Tip: Yellow leaves with green veins = iron deficiency. Treat with chelated iron.

Pruning and training

• Prune lightly after harvest or in late winter.
• Remove dead wood, suckers, and crossing branches. Thin canopy for airflow.

Flowering, fruit set, and thinning

• Most Citrus are self-fruitful. Indoors, shake branches or brush pollen for a better set.
• Thin excess fruit on young trees to avoid stress and promote larger harvests.

Soil health and repotting

• Maintain soil pH 6.0-7.0 for nutrient uptake.
• Repot containers every 1-2 years into slightly larger pots. Refresh topsoil annually.

Pest and disease prevention

• Inspect weekly for Scale, Mites, or Aphids.
• Maintain airflow and keep leaves dry at night to reduce fungus.
• Avoid overwatering to prevent root rot.

Seasonal checklist

• Spring: Resume feeding, prune lightly, scout for pests.
• Summer: Water evenly, provide shade in extreme heat, watch for mites.
• Fall: Slow feeding, thin fruit, prepare to overwinter containers.
• Winter: Bright indoor light, moderate water, watch for fungus gnats.

A Zesty Wrap-Up!

Citrus trees bring sunshine and fragrance to patios and gardens while rewarding you with juicy fruit. With proper planting, steady care, and quick pest solutions, your Lemon, Lime, Orange, or Kumquat will thrive for years. Add zest to your backyard or container garden and enjoy harvests that are truly homegrown.

Happy Planting!