So, you saw a cracked bark on a mango tree.
Is it dangerous? Will it kill your tree? What to do about it? In this article, you will find out everything about this problem.
Why are Mango Tree Barks Cracking?
Mango tree barks are cracking, for a few reasons, but the most common one is sharp temperature change between day and night. Other reasons are fluctuating growth conditions, improper application of fertilizers, or disease.
A cracking bark on a mango tree is a common problem. Kwanzan cherry, maple, and fruit trees, including mango, are among the trees that are susceptible to this type of injury. It usually happens in an early tree’s life. Trees with thinner bark will typically have more splits and cracks naturally occurring.
Here are the most common reasons behind cracking mango tree barks.
Sharp Temperature Changes
Sharp temperature changes between day and night, especially in the late winter, or early spring might cause a mango tree bark to crack. Frozen water within the phloem, xylem, wood, and inner bark expands and contracts while repeatedly freezing and thawing with fluctuating temperatures, causing the trunk to explode or split open.
Frost cracks often start from a wound inflicted earlier in the tree’s development. Frost cracking is more likely when there are high temperatures in the fall, high humidity, and high nitrogen levels. The crack might reach 5 feet (180 cm) or more in length.
Fluctuating Growth Conditions
When growth conditions of a mango tree are contrasting, it might also be the reason for bark cracking. Dry weather slows the growth of the tree. When it’s followed by wet, growth conditions may cause an excessive amount of growth, leading to splits in the bark.
The longer the mango tree suffers scarce water conditions, the less flexible it will become. When that dry period is followed by excessively wet conditions, young trees will over-satiate their hydraulic systems, often resulting in bloating. As the tree bloats, pressure builds against the hardened inner bark and may split the bark if that pressure becomes too high.
Sunscald
When the bark is exposed to the sun, it heats up substantially on warm winter days and is then exposed to freezing temperatures. Constant heating, and causes the death of the inner-bark. Usually, the south and southwest sides of young trees are prone to sunscald.
Suscald is visible in the spring growing season and appears as sunken or discolored bark, which splits and may fall off in patches. It might also appear on the trunk and branches of mature trees if they were heavily pruned in the fall.
Improper Application of Fertilizers
If you fertilize your mango tree the wrong way, at the wrong time, and with the wrong fertilizer, it also promotes bark cracking. Applying fertilizer to the trunk will make the tree more likely to crack. Also, cracks might develop when you fertilize a mango tree after midsummer. A fertilizer applied late in the growing season promotes young growth that’s sensitive to winter temperatures.
Disease
Your mango tree bark might also crack, because of phytophthora gummosis. It’s a disease that symptoms include small cracks oozing sap, giving the tree a bleeding appearance. Heavy rain washes away the sap. When the bark dries, it cracks and falls off, and over time the cracks grow larger, finally encircling the trunk.
Herbicides
Sometimes, you might cause bark cracks when you accidentally apply weed killers, such as glyphosate herbicides. Too frequent application of herbicides in the vicinity of trees, or used in overly high doses on the surrounding landscape, deteriorates the inner bark structure while eliminating the winter hardiness of the young mango trees.
What are the Dangers of a Cracked Mango Tree Bark?
The dangers of a cracked mango tree bark include the appearance of:
- Pests
- Insects
- Diseases
- Fungal infections
- Pathogens
It’s a serious problem. Diseases shouldn’t appear instantly, but they will develop later in the season. In the beginning, they might not seem problematic, but in the long run, will ruin the appearance of your tree, and might potentially stunt the growth of the tree, affect the quality, and quantity of fruits. If not treated properly, in many cases, they might cause your mango tree death within several seasons.
What Should You Do to Save Your Mango Tree with Cracked Bark?
That being said, you need to act fast, and effectively.
To save your mango tree, don’t paint or try to seal a split with paint or tar, because it’s not an effective method. Instead, you need to cut away the bark around a crack.
Therefore, do the following things.
1. Sterilize a sharp knife in a 70-percent alcohol solution.
2. Cut a line in the healthy bark 1 inch (2,5 cm) from one edge of the crack, working from the crack’s top to its bottom.
3. Sterilize the knife again.
4. Cut a line on the crack’s other side to join the top and bottom of the first line.
5. Remove the bark inside the lines.
After the operation, sterilize your knife again. Dip the knife for a few minutes. You can also sterilize your knife with a 1:10 bleach solution+water solution. After some time, the tree will form a callus and heal itself with time.
What Should You Do to Prevent Mango Tree Bark Cracking?
You already know how to heal the tree, but it doesn’t mean that the crack won’t occur on the other side of the tree, or on another tree. Therefore, you need to know how to prevent the cracks.
These are things you need to do:
1. Fertilize your mango tree properly.
2. Use white-colored tree wraps.
3. Plant evergreen shrubs to shade the southwest side of your trees.
4. Pruning the tree in late fall and winter months.
5. Water the tree on a regular basis.
6. Be careful with herbicides.
To prevent tree bark crackings, you need to apply fertilizer as soon as new growth appears on the tree in spring. I’d recommend applying a slow-release, 6-4-6, granular fertilizer (You can buy it here on Amazon) under the tree’s canopy, but avoid the trunk. That way, you ensure that your mango tree will be less sensitive to winter temperatures.
It’s also essential to protect your mango tree with white wraps that give your tree’s bark an extra layer of reinforcement. They reflect sunlight and prevent bark overheating. Moreover, white wraps protect the tree from the hazards of winter. You can buy this one on Amazon, and it will provide great protection, breathability, and water resistance.
You can also plant evergreen shrubs to shade the southwest side of your trees. That way, your mango tree will be less susceptible to weather fluctuations. You can plant for example american arborvitae, yew, creeping juniper, or euonymus, you can find out how fast it grows in this article.
Pruning is also pretty important. It entices a tree to grow. Make sure you do it in late fall, or winter. Spring and summer pruning may result in growth that will not have time to properly harden for winter months and become highly susceptible to frost cracks.
Watering your mango tree, especially in times of drought, is essential. Do it 2-3 times per week. It keeps the tree moist, and when the rain comes, it will not experience water shock.
When using herbicides, be careful. Ideally, use a herbicide that doesn’t contain an adjuvant, and don’t overspray it. Remember to maintain a 30-foot (9 meters) no-spray zone between the weeds you spray and your trees. Also, don’t use herbicides to treat tree suckers.
Sources
ronpaulgardencentre.com, toddsmariettatreeservices.com, homeguides.sfgate.com