Planting for the future: A Michigan farm family’s pine nut experiment

Ox Heights Farm and North Star Chestnuts is a diverse 180-acre farm in the northeast corner of Michigan’s lower peninsula, about five miles from Lake Huron and Rogers City. Abby and Nick Johnson and their five children produce tree crops including chestnuts from 1,000 trees and peaches. They also raise Dorper sheep and sell forest products including maple syrup, lumber, holiday greenery and firewood. Always interested in diversification, they planted their first Korean pine nut trees in 2017.

In 2024, the Johnsons substantially increased their pine nut groves when they received a Sustainable Agriculture Research Education (SARE) farmer grant to add 100 Korean and 100 Siberian bare-root pine nut trees.

These are cold hardy trees that produce pine nuts, a nutritious, high-value tree crop. The trees are well-suited to their sandy soil, but their existing plantings from 2017 and information from other growers shows that they are slow growing and can be difficult to establish. In this on-farm trial, the Johnsons were trying to figure out if they could improve the trees’ survival and growth rates.

Some North American pine nut growers hypothesize that soils in North America do not have the mycorrhiza that are symbiotic with the Korean and Siberian pine nut trees – native to northeast Asia – resulting in mortality and slow growth. Another hypothesis is that the young trees need to be kept out of sunlight and wind to maximize survival and growth.

The Johnsons decided to test these assumptions by planting four trial plots of 50 trees each: half Siberian and half Korean pine nut for each trial. Each method gets progressively more time-consuming and expensive. They chose to plant in frost pockets on the farm to take advantage of the crop’s cold tolerance.

“And so picking those spots that are cooler, that are not as well suited for other trees, that’s where we’ve kind of chosen to put them,” said Abby.

In the first plot, they planted the trees as they would native pines. In the second, they planted the trees like a native pine but added pine nut mycorrhiza inoculate purchased from a tree nursery. In the third, they again planted normally but included mycorrhiza inoculate collected from soil around the roots of their 2017 Korean pine nut trees. In the final plot, they planted like normal pines, added mycorrhiza inoculate purchased from a tree nursery and included protective cages to block sun and wind.

They also planted native Balsam firs in the same location to evaluate how the pine nut trees’ survival and growth varied from a native conifer. Native firs perform very well in their soil conditions. Because they had irrigation, they were able to provide a consistent soil moisture, eliminating water as a variable in the trial.

Over the next two years, the family monitored and measured the growth of the trees. Their first result was expected: In the absence of any treatment, the native fir trees had the highest survival rate (98%). The Korean pine nuts had an 88% survival rate and the Siberian 75%.

Abby said, “These still are not great numbers when you’re planting trees, but not too far off from what we had previously experienced with just our limited planting.”

The other results were more surprising. The commercial inoculant was associated with reduced survival in both pine nut species. The shelters mitigated this effect in the Korean pine nut but not the Siberian pine nut. Additionally, the average growth over two growing seasons was one to three inches, with neither treatment explaining the variability in growth.

Overall, the Johnsons reported in their final SARE report, “our experiment provides no evidence that inoculants or shelters are worth the extra work and expense on our farm when planting bare-root Korean and Siberian pine trees.”

Their on-farm science experiment wasn’t for naught. The trees they purchased came from Ontario, Canada, and sat at the border for nearly a week. Abby conjectures this could have impacted mortality and noted that picking up the trees directly from the nursery may have provided more successful survival rates. She suspects the stress from shipping may have contributed to reduced survival, particularly when combined with the negative effects of the commercial inoculant they tested.

In the future, she would like to test this conjecture by purchasing pine nut trees from a local nursery. She said, “I think there’s potential for tree nurseries here in the United States to provide pine nut trees to people who are interested in establishing them.”

The experiment also spurred Abby to try growing seedlings from their own seedstock. In early summer 2026, she stratified pine nut seeds in a refrigerator and then germinated them in pots. By mid-summer, these trees were about four inches tall, and Abby planted them into the orchard to fill the holes where mortality had occurred in 2024 and 2025.

Whatever happens, the Johnson family plans to keep planting food-producing trees.

Abby said, “It’s just a kind of a hopeful activity. You’re planting trees and it’s not for you. It is for you, but at the same time, you’re hopeful that this is something that’s going to stay for a long time. That’s kind of what we started with the chestnut trees and planting those in hopes that it’s something that our children will enjoy and be able to be able to work with.”

by Sonja Heyck-Merlin