Canopy Layer
Black Walnut, Juglans Nigra

Black Walnut, Juglans Nigra

You’d be nuts not to get one. This tree walnut disappoint you.


  • Cold hardiness zones: 4 – 9 (can withstand cold to -30° F)
  • Soil PH: 6.8-7.2, but it will survive in a wider range of soils
  • Watering needs: Average, though they prefer more in summer
  • Blooming Season: Mid-spring
  • Harvest season: September-October
  • Fruiting age: As early as 4 – 6 years for initial nuts, but 20 years for full crop.
  • Pollination for Fruit: Walnuts will produce nuts on their own, but they will produce significantly more with an additional variety of walnut, or another walnut grown from seed.
  • Size at maturity: 50-100 feet tall and wide
  • Sun needs: Full sun
  • Preferred habitat: A moderately moist mature forest.
  • Growth rate (vigor): Medium, about 1 – 3 feet per year.i
  • Reproductive rate (and methods): High once mature, mostly by seed dispersal (squirrels, other animals)
  • Average life span: 130 years, but sometimes up to 200.
  • Plant family: Juglandaceae


Though generally used for flavor and texture in cooking, its high levels of protein, starch, unsaturated fat, and fiber give it some potential as a staple food. It’s also a good source of vitamin B6, iron, vitamin E, manganese, magnesium, phosphorus, copper, zinc, potassium, and a dozen or so other vitamins, minerals, and vital amino acids.ii

Though a bit smaller than walnuts you might find in the grocery store at Christmastime, black walnut nuts are just as tasty, and far hardier to cool climates. Though the uniquely dark color of their shells make them look a little different than other types of walnuts, they can be used for any recipe calling for walnuts.

Aside from the nut, the tree itself also yields a sweet sap that can be boiled down like maple syrup. This is done at the same time and in the same way as maple.

There are several medicinal uses for black walnut bark and leaves, such as for headaches, skin problems, and toothache, which should be researched thoroughly before attempting.

Even at the end of its long life, black walnut continues to give, providing a beautiful wood that is highly valued for it’s quality and natural artistic patterns.

Clearly, black walnuts are a true food forest species.


Black walnut produces a chemical in its leaves and roots called juglone, which is harmless to humans and animals, but it can prevent the growth of many other plants. For this reason, it is advisable that any time you’re considering planting something near your black walnut tree you to do a quick Internet search for, “juglone sensitivity of _____” with the species you’re considering planting near your walnut. About half of the fruits and plants I search are just fine with walnuts around, but the other half are not. Just be aware that once it grows to maturity, your walnut will make a thick shade over a 50-100 foot area around it. So plants surrounding walnuts should be both juglone tolerant and shade tolerant.