Photo by Brenda Durealt
Black Wlanut
Black walnut trees planted at Curly Frog Farm, with trazel nut trees, day lilies and garlic for diversity.
In agriculture, trees themselves aren’t often seen as the crop; it’s the fruits and nuts where the outcome is focused.
Yet, if trees are looked at as an agricultural and business contributor, growers and farmers can expand their options whether they choose to grow trees for others to replant, to improve the land, or for lumber.
Many farmers have land that is unsuitable for their primary crops, and often those lands remain unused.
But that land can become a second source of income by planting some of the less common tree species, according to a presentation at this year’s Pacific Ag Show.
Dave Trotter, chair of BCAGRI offered up the insights and presentation of Michael Carlson, who has conducted years of research on birch, poplar and black walnut trees.
Trotter is a researcher emeritus at the Ministry of Forests, in the department of Lands and Natural Resources Operations.
Brenda Durealt of Kelowna’s Curly Frog Farm added her direct experience with black walnut and pawpaw trees.
Paper birch are common in B.C., creating dense forests of trees that reach up to 35 or 40 metres in just 10 to 15 years. Carlson’s study paired paper birch with the silver birch of Finland.
“We paired them in different trials in British Columbia,” says Trotter. “The silver birch is easy to grow, attractive, ornamental, relatively fast growing and tolerant to different soils.”
Concerns for the silver birch pointed out in Carlson’s work are the bronze birch borer and drought.
Switching to hybrid poplars, Trotter outlined details of a trial that used effluent municipal water.
“There are some very fantastic clones that are available,” Trotter says. “If you need trees in a hurry, this is the one.”
Poplars are great for shade or fence rows and the wood can be used for a wide range of products, but there is a downside.
“The market in B.C. [for poplar wood] has kind of collapsed,” notes Trotter.
He adds however that the wood runs in a 10 to 20 year cycle so there is still potential.
“They have pretty dramatic growth,” he says, but goes on to describe poplars as nutrient pigs that prefer sandy or silty loam soil, need the water table within one metre of the surface (or require irrigation) and need about two to three years of competing vegetation control.
When it comes to nut trees, nothing beats the resources of West Kelowna’s Gellatly Regional Nut Farm. Now a park, the nut farm was originally founded by Scottish pioneers David and Eliza Gellatly in 1910.
“He [Gellatly] was very interested in nut trees and nut tree genetics,” Trotter explains. “He got trees and modified them to meet the region.”
From the site much has been learned about both black and English walnuts.
“They grow here quite nicely,” he says of the black walnut. “They need water and have an incredible straightness.”
Both English and black walnut trees have similar ideal growing conditions like well-drained sandy-loam soils, regular irrigation and considerable growing season heat. Carlson’s notes add that while English walnuts are the ones most commonly eaten, they are grown in China, California and Oregon. There is a slowly growing market for black walnuts.
Durealt has planted thousands of trees and found great success with black walnut on her 26 acres, which flood annually. These conditions have also allowed her to create wetlands and growing areas known as ‘Chinampas’. She uses these for pawpaw trees, the largest tree fruit native to North America.
“The black walnut leaves and the hulls have this citrusy fresh scent,” she explains. “Historically, black walnut has always been a high value wood. It’s good with difficult conditions including flooding. It doesn’t taste like any other nut out there.”
Durealt is aiming for black walnut trees that provide flaw-free logs (about 21” in diameter and eight feet long) ready for harvest at about 30 to 40 years. She planted hers in a 15-by-15 foot grid intermixed with other trees and crops. Already she sees the exceptional straightness of the black walnut trees.
She uses bamboo poles tethered to the trees to encourage straight growth and prunes at the collar to prevent flesh cut holes in the trunk. The seedlings are cheap and hardy, and while cultivars are often found on known root stock this is more expensive and may not work in all conditions.
“The biggest challenge is processing the nuts,” she says.
While waiting for the trees to grow into lumber, she looks to the nut as a source of income. Black walnuts have an exceptionally hard shell making them a difficult sell.
If shelled, they garner about $15 a pound, so Dureault employs a simple but innovative technique; she runs over the nuts in her truck to remove the hulls.
The walnut husk fly is a pest to watch for, but Dureault notes the nut is not damaged other than the potential for a small stain.
The nut shells even find homes as dye, health products and abrasives.
Pawpaw trees were a different story. When Dureault attempted growing pawpaw, the first trees died. She persisted and is glad she eventually figured out the tree’s secrets.
“It’s an ornamental, is relatively insect and disease free,” explains Durealt.
The mango-sized fruit ripens in October and the custardy-soft flesh is used frozen, in baking, ice cream, eaten fresh and is working into the craft beer market as an ingredient.
“The seed source is very hard to find,” she says of the trees, and early growing is challenging.
The early years require shade, then at two years of maturity the trees need full sun with fruit expected at about six years or when the tree reaches about six feet.
Durealt loves tree farming but notes that crops like black walnut and pawpaw are definitely a side business.
“Another income is necessary,” she says.
Tree farming isn’t for everyone, but those willing to put in the time and make use of land not currently in production can reap the benefits of an unexpected crop. ■
