How to Grow and Care for White Mulberry Trees

White mulberry is the most common type of mulberry tree that grows in North America. White mulberry can be identified from its blackberry-shaped fruit that starts as white and turns purplish red as the season progresses. White mulberry trees tend to grow and thrive in any conditions within their hardiness growing zone.

White Mulberry Tree Care

Here are the main care requirements for growing the easy-care and hardy white mulberry tree:

• Plant in full sun.
• Provide neutral, well-draining soil.
• Water well for the first two years of the tree's life, then pull back on supplemental watering.
  
• Prune and remove new seedlings consistently.
  

Light

The species performs best if placed in an area that receives an ample amount of full sun but it is incredibly adaptable and will manage in part sun to partial shade as well. Though it can do well in almost all conditions, it's still best to place cultivars of the species in full sun.

Soil

It's rare to find a plant or tree like the white mulberry that grows so well in any soil condition. In urban areas, they are often known for growing in empty lots riddled with construction debris. The only condition it will not survive in is soil that is saturated consistently. Provide a cultivar with rich loamy soil that is well-draining with a neutral pH.

Water

White mulberry trees do not need any supplemental watering once established and at that point, they become very well suited to areas that experience drought conditions regularly. Until then though, it is important to proceed as you normally would with most trees and provide your newly planted mulberry with enough water to allow it to establish a good robust root system. This is easily achieved by watering your tree weekly during its growing season at a rate of 10 gallons per inch of trunk diameter measured by a caliper at chest height. Doing this for the first two years will ensure that your tree is healthy to be able to cope with stress.

Temperature and Humidity

The hardiness of the white mulberry is not an issue. It stands up well to droughts and cold weather in its habitable zone, USDA 4 through 8, quite well, but the main weather concern regarding the species comes from its weak wood. While it stands up to the weather quite well, its wood just does not have the strength to compete with strong winds or heavy build-ups of ice or snow on weak branches.

Fertilizer

You should not add supplemental fertilizer to a white mulberry tree as it grows vigorously on its own in even the most adverse conditions. Adding fertilizer will only speed the growth of this fast-growing tree, weakening the wood further and possibly causing tree damage during storms and poor winter weather. If you consider using supplemental fertilizer, you should test your soil before adding amendments to see what micronutrients are lacking and supply the fertilizer with the right NPK formulation.

Types of White Mulberry Trees

Consider planting a white mulberry tree cultivar that is sterile and bears no fruit (male) to avoid the tree from becoming weedy or messy from fruit drop. Only the female trees produce fruit. Or you can check out another species of mulberry tree native to your area. Here are a few fruitless white mulberry tree cultivars:

• Morus alba ‘Chaparral’ is a fruitless dwarf cultivar with a maximum height of 8 feet and deeply weeping foliage.
• Morus alba 'Pendula' is another fruitless dwarf and a weeping cultivar that grows a bit taller to 13 feet.
• Morus alba ‘Stribling’, 'Urban', and 'Kingan' are all fruitless male varieties with broad irregular leaves with medium green foliage.
• Morus alba 'Hampton' is a fruitless cultivar that grows to 50 feet.
  

Potting and Repotting White Mulberry Trees

White mulberry trees, most specifically dwarf types, can be ideal potted trees. Choose a large plastic container at least 12 inches wide and deep to start. Plastic is best because it will be lightweight and moveable. Make sure the pot has adequate drainage holes. Watch for roots growing out of the bottom of the pot. That means it's time to repot to a large container so the roots don't start aggressively searching for water outside of the pot. Use a good mix of potting soil and perlite. Place the pot in full sunlight (though it can tolerate shade) and water well.

Pruning

The chore of pruning your white mulberry will be done mainly for maintaining the tree to ensure it does not break under the stresses of winter weather or high winds. This should be done by looking for weak, intersecting branches with deep crotches, damaged or dying branches, and wood that is growing inwards towards the leader. This task should be done during the winter to avoid unsightly bleeding that occurs when the genus is pruned, which can in turn allow some diseases to infect the tree.

When pruning and trimming straight species, your second task will be the removal of any newly sprouted seedlings or saplings in the vicinity. Carefully remove from the root all plant material and dispose of the waste properly according to local ordinances.

Propagating White Mulberry Trees

It is very easy to propagate any mulberry tree, including white mulberry and its cultivars, using a cutting. Cuttings are preferred over the more difficult and hit-or-miss method of growing a mulberry tree seedling from seeds. You may even be able to simply take a 6- to 8-inch-cutting of a white mulberry tree any time of year and stick it in the ground and it will take root right there. Or, take these steps:

1. With a sterilized cutting tool, take a 6- to 8-inch cutting (virtually any time of the year) and remove all the leaves except at the top.
2. Stick the bottom of the cutting in rooting hormone.
3. Fill a pot with a well-draining soilless potting mixture, such as peat moss, vermiculite, and perlite in equal amounts.
4. Place the pot in a shaded area for up to 60 days to let the roots take hold.
5. Water to keep moist but not soggy.
6. Before placing the cutting in a permanent home, gradually expose it to the sunlight over a couple of weeks.
   

Common Pests & Plant Diseases

Morus alba does not suffer many issues from insects or diseases. It will occasionally become infected by bacterial leaf scorch, root rot, or cankers, but none of these will be a life-threatening risk.

The insects that might plague your tree are often flies and whiteflies that are likely attracted to the fruit mess. Borers may be an issue in warmer climates but will not pose a serious risk. Ultimately, insects and diseases don't merit chemical intervention and time will usually resolve the issues.

How to Get White Mulberry Trees to Bloom

Bloom Months

The tree flowers from March to April.

What Do White Mulberry Tree Flowers Look and Smell Like?

The tree's unremarkable greenish-yellow flowers do not have petals and appear more spikey. The flowers are droopy clusters called catkins that are about half an inch long (female trees) or 1 inch long (male trees). If the non-fragrant female catkins are fertilized they will give way to berries in June.

How to Encourage More Blooms

You may not want to encourage more blooms to reduce the fruit drop mess. In addition, the flowers aren't showy. But if you do want more fruit, just make sure the tree is in the sun, watered regularly, and fertilized once a year. If you are not seeing flowers on your white mulberry tree, it may mean that a late spring frost has killed the flower buds, but it will likely rebound the next year.

Common Problems With White Mulberry Trees

Besides the mess an invasive, fruited white mulberry tree makes, there are only a couple of other issues with this tree.

Damaging Roots

Birds drop seeds of white mulberry trees all over the place and the aggressive roots can lift and damage sidewalks, foundations, drains, and sewer systems. It's important to remove white mulberry tree shoots from vulnerable areas.

Weak Trunks

Younger white mulberry trees under 10 years of age can have weak, fragile trunks. That means they can easily break or topple over in strong winds and heavy rain, damaging anything that gets in their way.