The leaves and unripe fruit of mulberry contain a latex that is mildly toxic to humans. It is important to keep in mind that mulberry trees have very prolific, fast-growing roots. Plant your tree away from important structures such as your foundation, driveway, or garage, and features such as utility, septic, or sewage lines, so you don’t risk the roots damaging vital elements of your property. You should also take the tree’s mature height into consideration and pick a spot where it can be kept relatively free of pruning (which causes it stress) and let it do its job of producing berries and enjoy the many fruits it will offer you.
Light
Mulberry trees can thrive in both full sun and partial shade conditions, though as with many fruiting trees, more light equals more fruit.
Soil
Mulberry trees are somewhat adaptable and can deal with clay, loam, and sandy soil with ease, as long as the mixture can maintain sufficient drainage. The trees can thrive in a range of pH levels varying from neutral to mildly acidic.
Water
Water your mulberry tree deeply and regularly after initially planting it in order to help it establish a strong root system—two to three gallons per week for the first year is recommended. Once established, mulberry trees are fairly drought tolerant, though prolonged dry weather can lead to a reduction in fruiting or early dropping of the unripe berries.
Temperature and Humidity
Depending on the species, most mulberry trees are cold-hardy and can handle temperatures as low as minus 25 degrees Fahrenheit during dormancy. They produce the optimal amount of fruit in regions where growing-season temperatures are between 68 and 86 degrees Fahrenheit.
Fertilizer
Mulberry trees often do quite well with no fertilization, though they can benefit from a yearly application. Feed your tree once in late winter, using a balanced 10-10-10 mixture and measuring out 1 pound of fertilizer for each inch in the trunk’s diameter.
Types of Mulberry Tree
There are five species of mulberry trees, three of which are likely to be seen in North America:
Morus alba: Also known as a white mulberry tree, this is the most common mulberry species found in North America. This native of China can be easily distinguished from other trees in the genus thanks to its blackberry-shaped fruit, which begins white but darkens to purplish red. It is available in the nursery trade in several cultivars that are ornamental and sterile, making them more suitable for landscape use. Morus rubra: The native North American red mulberry tree has rough leaves that are twice as long as Morus alba and feature a coarse hairy underside. The fruit starts light green then turns to red or dark purple when ripe. Red mulberry trees are often difficult to find in the nursery trade but they can be found growing wild in eastern Canada and the U.S. Morus nigra: Black mulberry trees average 40 feet tall and feature dark purple (almost black) berries that are quite large when ripe. This native of Asia is not commonly found in North America. Morus australis: Also known as Korean mulberry, this species is a small tree, reaching only 20 to 30 feet at maturity. It features light green foliage that is slightly glossed and fruit that ranges in color from almost white to deep red and purple. It is not a common landscape tree in North America. Morus celtidifolia: Texas mulberry trees are native to the Southwest and appear more shrub-like, growing to a maximum height of just 25 feet. The edible fruits are red, purple, or nearly black and are fantastic for drawing wildlife to your landscape, especially birds.
Pruning
Routine pruning is not necessary with this tree, but damaged or crossing shoots should be pruned away in late fall or winter while the tree is dormant, which helps avoid sap loss.
Propagating Mulberry
Mulberry trees are easily propagated by rooting semi-hardwood branch cuttings. Here’s how to do it: Not every cutting will successfully root, so it’s a good idea to take at least four or five cuttings to increase your odds.
Growing Mulberry From Seed
Mulberry trees are incredibly easy to grow from seed, as evidenced by the rampant self-seeding they produce. Fruits collected from the tree can be dried to collect seeds for planting, or you can simply wait for volunteers to spring up and carefully transplant them to new locations.
Potting and Repotting Mulberry
Container culture is not common for these plants, since they are fast-growing and can quickly achieve a size that’s too large for most containers. That said, if you are willing to prune often and willing to sacrifice the tree when it becomes too large after a few years, it’s entirely possible to grow mulberry in a large container for a sunny deck or patio, though the messy fruit can be a hindrance in these locations. Use ordinary commercial potting soil amended with plenty of compost, in the largest, widest container that’s practical. It’s better to start with a large pot rather than repotting as the plant grows larger, as repotting is not very practical. Be prepared to water and feed more often with a container-grown mulberry tree. For winter, try to move the potted tree to a slightly sheltered location.
Overwintering
Protecting the trunks of young trees with metal shields or hardware cloth for the first few years will shield them from rabbits, deer, and other browsing animals that gnaw on the bark. After three years or so, the trees are usually large enough to resist animal damage. Routine fall cleanup of fallen fruit is a good idea to reduce the rampant self-seeding that occurs with mulberry trees. These hardy trees require no protection against winter cold if they are being grown within their accepted hardiness range.
Common Pests & Plant Diseases
Mulberry trees may have to contend with a variety of pest issues, including whitefly, scale, and mealybugs. The good news is that these bugs won’t really cause much damage to mature trees—they’re tough enough to withstand it, which is good because treating a large 50-foot tree is no easy feat. If you notice signs of an infestation on a more vulnerable young sapling, you can apply a horticultural oil such as neem oil. These trees are relatively free of disease problems, though bacterial blights and fungal leaf spot diseases may sometimes occur. Diseased plant parts should be removed as they are noticed. Fungal diseases are rarely fatal and usually require no treatment. Mulberry trees are more likely to incur pest and disease problems in warmer climates.
How to Get Mulberry to Bloom
Generally speaking, homeowners don’t want to encourage mulberry trees to bloom, since the flowers aren’t showy and they lead to messy fruits that are of no use unless you want to harvest them for jams, jellies, or other recipes. But if you want to encourage blooming and fruit production, simply make sure the tree’s basic cultural needs are being met—plenty of sunlight, regular water, and annual fertilizing. The most common reason for bloom/fruit failure on a mulberry tree is lack of soil nutrients and late spring frost that kills the flower buds.
Common Problems With Mulberry
The most often mentioned issues with mulberry trees involve their messiness and invasive spread.
Stains From Fruit
The fertile, fruiting varieties of this tree are often considered nuisance plants in urban environments, since the fallen fruit will stain pavement and cars, and the stains can easily be tracked indoors. To avoid this, it’s best to plant one of the sterile cultivars that don’t produce fruit. If you do want the fruit for the benefit of feeding birds or making jams, try to position the tree in an area of your yard where the fruit will not create a mess.
Rampant Spread
Mulberry trees can spread very easily through self-seeding. Garden areas immediately around a tree may see hundreds of volunteer seedlings, which, if not immediately plucked, can quickly develop root systems that make the saplings hard to eradicate. If you have a fruiting mulberry tree, learn to recognize the seedlings and pluck them out as soon as they appear.
The two methods of picking mulberries are handpicking, which can be very tedious, or placing a tarp or old sheet under the tree and giving it a good shake. You can then collect the unbruised fruit and carefully prepare the berries as part of jelly or jam, or freeze the berries to use them periodically as desired.
And keep an eye out for volunteer plants sprouting up; any mulberry tree in the neighborhood will spread itself by seeds in the droppings of birds that consume the fruit.
If you wish to use mulberry as a small shade tree in more heavily trafficked areas, it’s best to choose a sterile cultivar that produces neither fertile seeds nor fruit.
