Mulberry (red and black)

About Mulberry (red and black)

Mulberries are fast-growing trees with sweet, blackberry-like fruit that ripens in early summer. Red mulberry is a native eastern tree; black mulberry is an Asian species that is less cold-hardy. Skip white mulberry (Morus alba): USDA PLANTS flags it as invasive, Wisconsin restricts it as an invasive plant, and it crosses readily with native red mulberry, so many 'mulberry' cultivars sold are white mulberry or white-red hybrids; check the species before you buy.

Red mulberry is listed for zones 4-9 (NC State); black mulberry is hardy only to about zone 7 (UW-Madison CIAS).

When to plant

Timing is counted from your average last spring frost (and first fall frost). Sow & Tell works out the actual dates for your ZIP code.

Transplants usually start bearing in 3 to 4 years (UW-Madison CIAS). Red mulberry trees are usually either male or female, so a tree that never fruits may be a male (NC State; USDA Forest Service). Unpruned trees can grow very tall (up to 80 feet), so prune to keep the fruit within reach (UW-Madison CIAS).

Soil

Deep, rich, well-drained loam; red mulberry grows on clay, sand or loam over a wide pH range and does best on moist, well-drained sites (NC State; UW-Madison CIAS; USDA Forest Service).

Plant in deep, well-drained loam in full sun (UW-Madison CIAS; NC State).

Feeding

Poor soil gives weak growth (NC State); prune to keep the tree a manageable size for picking (UW-Madison CIAS).

Harvest

Fruits turn from red to dark purple and drop when fully ripe, from late spring into summer (NC State; USDA Forest Service). Ripe fruit can be gathered by shaking the branches over a sheet (UW-Madison CIAS).

Mulberries give one crop a year, maturing in late spring to summer (about May-June in North Carolina). Red mulberry trees are usually male or female, so only female trees fruit.

Varieties (7)

Only 7 named mulberries could be sourced, and details are thin. Sources rate the red mulberry species, not cultivars (NC State: Zones 4a-9b). No black mulberry (Morus nigra) cultivars were documented in the sources that could be opened. White mulberry hybridizes with red mulberry and the two are often confused (US Forest Service), so many named 'red' mulberries likely carry white mulberry genes; pure white mulberry cultivars are left out because white mulberry is invasive in several states (Wisconsin lists it as noxious and invasive).

Pests to watch for

Birds, Scale insects, Whiteflies, Twospotted spider mite

Diseases and problems

Bacterial leaf scorch, Leaf spot, Powdery mildew, Root rot

In the kitchen

Eaten fresh or frozen, dried, juiced, baked into pies and tarts, or made into wine (UW-Madison CIAS).

Keeping it: Ripe mulberries are fragile and don't keep: refrigerate them unwashed and eat them within 2 to 3 days, or freeze them.

Safety: Eat only ripe fruit: unripe berries and the milky sap can cause stomach upset and, rarely, hallucinations, and the sap can irritate skin (NC State). We found no research-based guidance on pregnancy or drug interactions for the fruit.

Pets: Not toxic to dogs, cats or horses (ASPCA lists mulberry tree, Morus sp., as non-toxic)