Citrus Pests & Diseases

Citrus trees are relatively easy to grow and with the proper care, you can have Citrus trees with beautiful blossoms and luscious fruit that will last for decades. Caring for your citrus tree starts as soon as you remove them from your box.
Please remember that if your tree came planted in a pot, you should leave it in the pot for at least 2 weeks to minimize shock. Remove the tree from the plastic bag wrapped around the pot, water it, and place it in a "partially" sunny location for at least a week, before you attempt to place the tree in the full sun.
After one week you can then place the tree in full sun (IF it is not in shock.)


Tree care is based on a 4 point system

1. SUNSHINE
It is essential that your tree gets 6-8 hours of sunshine daily. In the northern regions of the US, this can be a little more problematic, (in the winter months) in this case you can supplement with a plant grow bulb in addition to sunshine. It is critical that your tree is given 6-8 hours of daily sunshine, this is a requirement for a healthy productive tree. A lemon tree dropping leaves or any citrus tree is an issue with lighting.
Citrus trees get their energy to maintain themselves from the sun, if the tree isn't getting adequate direct sun it is detrimental to its health.


2. WATER
It is crucial that you use the deep watering method when watering citrus. The majority of plant demise is due to overwatering, it is detrimental and should be avoided. A simple inexpensive moisture meter can prevent an overzealous gardener.
Moisture meters are around $10.00 and can give peace of mind to the questioning gardener on whether or not to water. Watering your trees for a few minutes every few days is NOT acceptable.
Deep Watering Method
https://lemoncitrustree.com/store/citrus-blog/2018/10/19/deep-watering-method-for-potted-citrus-trees/

3. FERTILIZER
It is crucial that you remember to fertilize your tree. Nitrogen deficiency is one of the leading causes of yellow leaves. Citrus trees are heavy nitrogen feeders. Without nitrogen, your tree CANNOT produce fruit. Fruiting trees remove nitrogen from the soil and convert it into fruit.
We recommend a 2/1/1/ OR 3/1/1 ratio fertilizer. The first number of any fertilizer is nitrogen and it should be double the other two numbers.
Citrus should be fertilized in  Mid- February, through mid-September. If you live in the south and your tree is planted outside do not fertilize after mid-September because that encourages the tree to start new tender growth during the winter when there is a danger of frost.
Feeding Recipe For A Happy Tree
https://lemoncitrustree.com/store/citrus-blog/2015/08/11/feeding-recipe-for-a-happy-tree/

4. PREVENTION
The old saying "an ounce of prevention is worth a pound of cure" is so true when it comes to preventing your trees from fruit and citrus parasites.
It is imperative that you protect your investment, a little prevention goes a long way.
It is vital that you educate yourself on hazards that could cause undue stress or extreme danger to your citrus tree. Regardless if you have Meyer lemon tree problems, lime tree problems or any variety of orange trees like satsuma trees and avocado trees, even the fruit trees,  the pest prevention will be the same.
If you notice ants on an avocado tree or citrus or any fruit tree,  do not ignore ants as they farm insect pests.
An avocado losing leaves in summer or a citrus tree could be due to a pest.
Pest Prevention
https://lemoncitrustree.com/store/citrus-blog/2015/08/21/bath-time-for-your-citrus-tree/


WINTER CARE AND LEAF DROP IN WINTER

After you take your tree inside in the fall before winter you should make sure to only water the tree with WARM WATER ONLY. Water can be frigid in the winter coming out of the tap, so be mindful of the water temperature before watering
The root area of the pot is just as important as the foliage of the tree, and if the root area gets too cold, the tree will begin to drop its leaves.
During the day it helps if the pot is elevated to the window, so the pot also receives warmth from the sunshine.
Also in the summer if you use a garden hose to water your tree DO NOT make the mistake of leaving water in the hose, the water left in a garden hose can get very hot in the summer, cooking in the sun. Make sure you always empty your hose and get fresh water in the hose, before you water the trees. Green leaf drop is a problem when trees are inside for the winter.
Lighting is usually the issue when green leaves drop off an otherwise healthy tree. If your orange citrus or lemon, or lime tree problems include green leaf drop you'll need correct full spectrum high lumen lighting.
Winter Recommendations For Indoor Citrus
https://lemoncitrustree.com/store/citrus-blog/2015/10/05/winter-recommendations-for-inside-citrus/



TIPS ON CARING FOR YOUR INVESTMENT

It is vital for tree care to do a few preventative steps to ensure that your tree stays healthy.
You should be familiar with the graft area of your tree, and not allow growth below the graft area, as this will eventually take over and kill your tree.


GRAFT AREA

BRACKET SHOWS GRAFT AREA
The Red arrow is a sucker and needs to be pruned off. The lighter part of the branch V-shaped is the grafted area.  Any growth below the graft needs to be removed. The whiter branch near the graft is fine, it is only the branch that sprouted BELOW the graft that is a concern. Some of our trees are not grafted.



ROOT CROWN AREA



ROOT CROWN
It is critical when transplanting the tree that the root crown is not buried under the soil, as this could cause the trunk to rot away from the rootball.
Never dig around the area on the topsoil. You can easily break the fine root system by digging in the soil.

RECOMMENDED PRODUCTS
We have recommendations to help with tree care. Fertilizer, Lighting, Pest prevention, etc.
https://lemoncitrustree.com/store/citrus-blog/2019/11/07/recommended-products/


DETAILED TREE CARE
https://lemoncitrustree.com/store/citrus-tree-care-containers


PESTS

CREATE A PEST BARRIER
For Citrus pest control creating a barrier between the soil and foliage is essential.
First, take a wide piece of masking tape or tangle guard, long enough to wrap around the tree.



Tape barrier
Tape the tree with wide masking tape. It is essential to make sure that the tree is completely wrapped. Then you'll need to wrap the support stick separately or remove the stick.
Once the tree trunk and support stick are wrapped, you can add tanglefoot to the tape. 
DO NOT WRAP THE WHOLE TREE TRUNK!
Only the width of wide masking tape is needed, to prevent access.
When changing the tape,  wash the area that had the tape to remove the sticky glue that was on the tape, and then place the tape in a different area of the truck.


This barrier will catch ants and prevent them from gaining access to the foliage of the trees. Since your tree is a good food source of honeydew.
REMEMBER- Check tape when you water your tree, to make sure ants haven't built a bridge across your barrier, and do not push the tree against a wall or railing or other plants, as insects would just climb them to gain access to the foliage of the trees.

Taping the tree will also help prevent spider mites and snails from gaining access to the tree. But it is essential to know spider mites can get blown through the air on a windy day. Other preventives that you could consider using are essential oils, such as tea tree, eucalyptus, peppermint, or wintergreen one dropper mixed with water in a spray bottle. Do not spray these directly on your tree, use these to spray the outside of the pot and surrounding area to deter pests. Neem oil can be sprayed on your tree and is an excellent deterrent against pests.
Essential oils also make great homemade leaf-miner spray.

If your tree is infested with anything you must wash your tree with Dawn dish soap and warm water, scrubbing with a dishcloth.  Make sure the top side and underside of leaves are entirely washed and scrubbed of sooty mold and cleansed of any sticky substance. You can use a toothbrush in hard-to-reach areas, such as a crevice at the Y part of a branch. Treat the tree once it is clean with a horticultural oil or neem oil.
It is IMPORTANT that all insects are removed, so take care to educate yourself on the insect infesting your tree. These will be listed further in this article.


Ants
Ants form symbiotic relationships with a variety of arthropods including scale insects, mealybugs, cottony cushion scales, whiteflies, and aphids. Ants are a lot like humans, they domesticate other insects like humans domesticate cattle. Ants will carry these insects up the tree and drop them onto foliage and branches. These insects use sharp mouthparts to pierce into plants extracting the sugary goodies. Then the ants will walk up and tap the scale or an aphid with a foreleg or antennae and on cue, the scale or aphid will give up a droplet of honeydew. Ants drive off a host of potential predators of the scale and aphids and so for payment for this ants protect their flocks, and for this protection, ants are rewarded with honeydew. Ants move their herds of bugs from "pasture to pasture" as each food source is used up. Ants are like cattle ranchers moving their herd from pasture to pasture. Protecting your tree from ants is essential.

If at any point you notice that your potted tree has become infested with a colony of ants, making themselves at home in the soil of the pot, then it is an emergency. You must kill the colony!

Use a small jar lid and pour in Mountain Dew, mix in 3 pinches of Borax Laundry Detergent. Set the lid with this mixture close to your pot, about 2-3 feet away from your potted tree. If you mix too much of the borax, it will kill the ants immediately, and they will not have a chance to take it back to the colony, killing all the ants in the colony. So be sure you don't mix it too strongly. If you notice a lot of dead ants near your mixture, then the mixture is too strong.

 

Ant getting drop of  honeydew from scale


SCALE
Looks like blisters all over the branch. Included in the photo, is a very faint web (spider-mite) that is attached from thorn to branch
When the scale is attached to the tree, it often appears as crusty or oatmeal-like or waxy bumps on tree, often it is mistaken for parts of the tree’s own growth. The picture clearly shows bumpy beige waxy growth. These are insects that suck sap from plants and produce a sticky substance called honeydew. Honeydew if left on the tree will then turn to black sooty mold.


 
Branch with scale, honeydew dripping off leaves and branches, and Citrus fruits.
The dark brown discoloration in the photo is scale pests.



MEALYBUGS

COTTONY CUSHION SCALE

HONEYDEW
Leaves saturated with honeydew, dripping from a leaf will cause fruit flies to be attracted to your tree and can be a warning sign that the tree is in distress.
Also, spider mites and a web to the right of the main leaf.

 SOOTY MOLD

SOOTY MOLD
As scales suck fluid, they create an environment ripe for the fungal disease called black sooty mold. Honeydew, if not removed will turn to black sooty mold and will become prevalent on leaves, twigs, and branches.
As the branches, twigs, and leaves turn black, the mold will reduce the trees' ability to conduct photosynthesis.
All that applies to the scale also applies to many other insects and how they affect your Citrus trees such as Aphids, Spider mites, Mealybugs, and Citrus Thrips.

Aphids crawling on a branch


 

 Aphids on the underside of a leaf, with larvae and eggs

APHID

SPIDER MITE

SPIDER MITES
Infestation of mites will usually infest the tree or plant in large numbers, and they damage leaves and plants. They suck the nutrients of the plants and leave them to die.
Webs on your citrus will indicate a spider-mite infestation.

FUNGUS GNAT
The majority of Citrus Tree death is over-watering. It is imperative that you DO NOT OVER-WATER your tree. Over-watering can create a perfect environment for Fungus Gnats that eat at the root system of the tree and will eventually kill your Citrus tree.  A moisture meter will prevent this from happening.

LEAF MINER
Although leaf miner is unsightly, it's typically not too damaging to Citrus Trees. Leaf miner is identified by squiggly lines in the leaves.
Treatment: spinosad to treat the adult insects

CITRUS THRIPS



Damage caused by Citrus Thrips.
Small orange-yellow insects whose feeding activities scar and damage the surface of the fruit.
The insects feed on the fruit buds and puncture the epidermal cells, leaving scabby, grayish, or silvery scars on the rind.

SNAILS
Snails will eat citrus fruit so it is essential to keep a proper sanitation program around the citrus tree. Do not allow dead foliage to build up inside the pot as this could fill up pretty quickly with snails and slugs. It is essential to have a barrier between the soil and the foliage to prevent slugs from climbing up the tree and eating the foliage and fruit.

WHITEFLY
It is crucial that you inspect your tree at least once a month to ensure that you have no infestation. Egg clusters or whitefly larvae will be present on the undersides of infested leaves. Remove larvae or nymph-infested leaves from your citrus tree by hand and treat the tree with neem oil.

 SWALLOWTAIL BUTTERFLY

SWALLOWTAIL BUTTERFLY LARVAE (Orange-Dog)
The swallowtail butterfly will lay her eggs on the leaves of citrus trees the larvae are the Orange dog caterpillars, which eat the leaves of citrus.
They usually are not harmful to the tree unless the tree is young. The dots on the head are horns that will pop out when he is warning you to back off. He looks pretty scary when he does it.


DISEASES


FUNGUS AND MOLD

 MELANOSE FUNGUS

MOLDY FRUIT
A fungicide can prevent many fungal infections.

GREASY-SPOT

CITRUS-SCAB
It is vital that you check your tree regularly to prevent fungus and treat the tree with Liquid Copper Fungicide.
One of the first signs that a citrus tree may be suffering from root rot is that the fruit has blemishes or decaying or yellowish-brown spots.
A fungus or root rot can cause citrus leaves to become moldy or have blackened veins or black lesions. Root rot causes a slow decline of the tree so it is imperative you have adequate soil drainage and avoid overwatering. As root rot advances, the bark cracks and dies leaving dark sunken cankers on the tree trunk. Prevent any problems before they start, use Copper fungicide which is effective if used regularly to prevent many of the common fungus problems known to citrus.


CITRUS DEFICIENCY




 
NITROGEN DEFICIENCY
Nitrogen deficiency will limit tree growth and fruit production and is expressed by light green to yellow foliage.
Overwatering your tree will cause yellow leaves if your Citrus has yellow leaves but you know you are not overwatering then your tree has a Nitrogen deficiency.

PHOSPHORUS DEFICIENCY
Phosphorus is essential for raising healthy citrus trees, but no matter the variety, they need only modest amounts of it. Growth is reduced when the supply of Phosphorus is too low and the symptoms appear first on older leaves. Symptoms: Small leaves that may take on a reddish-purple tint. Leaf tips can look burnt and older leaves become almost black. A research project has found phosphorus deficiency to be a contributor to citrus greening disease symptoms. By applying phosphorus, growers could potentially eliminate greening symptoms and improve fruit yield.

MANGANESE DEFICIENCY
Manganese deficiency symptoms are a light yellowing or whitening of green plant tissue because of a decreased amount of chlorophyll.
As the stress increases, the leaves take on a gray metallic sheen.

 
SULFUR DEFICIENCY
Veins and petioles show a very distinct reddish color. Similar to nitrogen deficiency with yellowing leaves but sulfur deficiency is much more uniform over the entire plant. Brown lesions often develop along the edges, and the leaves tend to become more erect and often twisted and brittle.

POTASSIUM DEFICIENCY
Potassium deficiency causes fruit to become smoother, with thinner rinds, and causes smaller fruit to develop. Leaves become yellowish with edges bent downward.

IRON DEFICIENCY
Leaves appear as dark green veins, with yellowing between.

ZINC DEFICIENCY
Extensive yellowing develops between veins when zinc is deficient.


TRANSPLANTING-
 https://lemoncitrustree.com/store/citrus-blog/2023/04/26/planting-trees-in-pots/


Please contact us at support@lemoncitrustree.com or call if you need assistance

 Lemon Citrus Tree
 866-216-TREE (8733)