How to Grow Black Mulberries

At a Glance

Quick Facts

Factor	Value
Soil pH	5.5 - 7
Drainage	Deep, moisture-retentive but well-drained (RHS)
Lifecycle	Deciduous tree, dioecious or monoecious depending on source population -- Growables.com notes seeds are rarely found in US-grown fruit. Genuinely slow to establish: RHS states trees take around 8 years to start fruiting from young stock, while Growables.com gives 10+ years specifically for seed-raised trees -- both figures reflect the same real characteristic, just for slightly different starting material.
Edible parts	fruit

Soil & Growing Conditions

Water: Water newly planted trees regularly from spring to autumn for the first few years; established ground trees need little extra water except in prolonged dry spells (RHS). Growables.com adds twice-weekly watering on light soil in year one, weekly on clay.

Soil pH range

5.5 7

Span reflects genuine variation between the cited authorities, not a single agreed figure.

Growth Stages

Stage	BBCH	Notes
Planting and establishment	0	Plant while dormant, autumn to spring, settling in best in spring (RHS). Choose a sunny, sheltered site with plenty of room -- mature trees reach up to 9m tall and wide (RHS); Growables.com recommends spacing at least 15ft apart.
Framework training and pruning	3	Train a bush form by cutting the leader to 70-90cm with a framework of 8-10 branches, or grow as a half-standard (1.2-1.5m) or standard (1.8-2.1m) (RHS). Prune only while fully dormant, between leaf fall and mid-winter -- mulberry bleeds heavily from cuts made at other times (RHS; Growables.com, which also advises avoiding cuts over 2in diameter).
Leafing and flowering	6	Leafs out nearly 2 months later than other mulberry species (Growables.com).
Fruiting and harvest	8	Slow to begin fruiting -- around 8 years from young stock (RHS), or 10+ years from seed (Growables.com), though smaller/compact varieties fruit sooner. Harvest August-September as fruit turns from red to glossy black (RHS); Growables.com gives an earlier May-June season in some warmer regions.

Harvest & Storage

When to pick: Fruit turns from red to glossy black, soft and juicy when ripe (RHS). Pick lower fruit individually by hand wearing gloves; for the rest, spread a sheet beneath the canopy and shake the branches so ripe fruit falls while unripe fruit stays put (RHS; Growables.com). Ripe fruit stains readily and indelibly -- Growables.com notes the juice of green, unripe mulberries can be used to remove the stain from hands.

Storage

Unwashed berries keep several days refrigerated (Growables.com).

Diseases

Mulberry leaf spot

low

Fusicladium/Cercospora spp.

Named directly on RHS's own growing-guide page; RHS does not specify a single named pathogen so this is recorded at genus level rather than inventing a specific species.

Powdery mildew

low

Named directly on RHS's own growing-guide page as "powdery mildews".

Coral spot

low

Named directly on RHS's own growing-guide page.

Pests

Birds (fruit)

low

Aves

Named directly by RHS; the source notes birds will hopefully leave plenty of fruit hidden among the leaves.

Caribbean fruit fly

low

Anastrepha suspensa

Growables.com notes this fly sometimes infests fruit in South Florida.

Sources

1. Growables.com (Julia Morton reference material) - Black Mulberry, Morus nigra

   USDA zones 7-10, some cultivars zone 6. Best in hot dry Southwest or cool wet Northwest coastal US. Soil: tolerant of poor infertile sandy soil, pH slightly acid to highly alkaline, good salt tolerance. Full sun to partial shade. Spacing 15ft+. Propagation: seed (10+yrs to fruit, sow immediately after extraction), sprig-budding grafting (difficult, excessive bleeding), hardwood/softwood/root cuttings. Slowest-growing mulberry species, 30ft x 35ft, gnarly zigzag low canopy, lives 300+ years. Pruning: minimal after framework training, remove dead/overcrowded wood only, avoid cuts over 2in diameter (excessive bleeding), dormant season only. Irrigation: twice-weekly year 1 on light soil, weekly on clay; water during drought to prevent early fruit drop. Fruiting: leafs out ~2 months after other species, season early May-June (later in some regions). Harvest: full ripen on tree, shake over sheet, separate from debris in a pail of water; berries collapse and stain when squeezed -- green (unripe) mulberry juice removes hand stains. Pests: Caribbean fruit fly (South Florida). Dioecious; male trees extremely allergenic pollen, female trees cause few allergies. May need fungal/bacterial sprays in humid regions. Flavour: high sugar/antioxidants/organic acids, grapefruit-like tartness blend.

2. Useful Temperate Plants - Morus nigra

   Mirrors FAO Ecocrop. Fetched and parsed directly for the numeric soil pH range.

These 2 sources are specific to this region. The full list of 3 sources behind this guide (Growables.com (Julia Morton reference material), Royal Horticultural Society, Useful Temperate Plants) is in the references of our UK guide to black mulberries; they describe the plant itself, which is the same wherever it grows.