Plant Exchange Blog

Welcome to Plant Exchange Blog. This week’s post is longer but it’s worth it to find out how a couple are living their dream about nut trees.

For Darrell and Martha Ausborn, an idea germinated and grew into possibility by the time they settled in Yankton County nine years ago. They live on ten acres of rolling hills about 1.5 miles northwest of the dam at Lewis & Clark Lake.

Darrell is a retired forester who trained at Iowa State University. He spent most of his 33-year professional life managing forests for timber production. His idea for growing pecan trees started in Alabama.

“In the 1970’s and 80’s we saw pecan orchards all over, many of them abandoned,” Darrell said. “Maybe they were planted in the 1930’s. Markets may have changed…I always wanted to work with a pecan orchard. The opportunity to manage an orchard did not present itself during my career. But now we have a chance to grow a few pecan trees– maybe 10 instead of a 100.”

Their Yankton acreage used to be horse pasture. Darrell found many scattered fieldstones on the ground, so he thinks maybe the land hasn’t been under plow. Since the horses were removed, native grasses and wildflowers have appeared.

He says that soil on the acreage is of high quality. Topsoil is 8-12 inches deep, with natural organic matter; deeper in protected draws than hilltops. He has noticed a “microclimate “on his land that softens the first and last frosts of the season.

Nut trees he grows here are rated for USDA Zone 5. The zone 5 trees may be considered “edge-of-zone” for this region in some difficult weather years or in open and less sheltered areas.

“What I’ve seen on vegetative maps, I gear us for USDA Zone 5 plants. If we don’t want to be disappointed, we put in Zone 4 plants,” Darrell said. Other trees he plants for timber, cover, native replacement trees, or beauty. They include hackberry, ash, oak, locust, ponderosa pines, lindens, and maples.

The nut trees he is trial growing so far are hazelnuts (filberts), heartnuts, black walnuts, pecans, English walnuts, Chinese chestnuts, hickory, butternuts, and one fruit tree species, pawpaw. Here are some butternut clusters developing.

“We thought we’d give these a try,” he said. “We’re on the extreme edge of the eastern hardwood forest.”

“It’s a joy to be outside and try new plants,” Martha said. “Because no one has tried plants, doesn’t mean it can’t be done. We might make enough mistakes that someone can take what we have done and do something better.”

Grow the Trees

Darrell took master gardener classes in Yankton to find out more how to grow and care for trees. In his forestry experience he managed large tracts of native hardwood and softwood trees. The activities being done now are more horticultural. He works with individual trees instead of a stand of trees. Martha had master gardener training from Iowa. They also grow vegetables and fruits on their land.

They find some grower resources from the Internet. Most helpful to them have been two organizations in which northern plains nut growers compare notes. One they have found helpful is the Nebraska Nut Growers Association from Valparaiso, Nebraska. The other is the national Northern Nut Growers Association. Nearby states that have nut grower organizations include Iowa and Missouri.

Through networking in the organizations, Ausborns find information about recommended or newly developed cultivars, growing tips, and current disease and pest information. They interact with nut growers from other states who are in business or hobby farming nut trees.

“We find a lot of people just like us with not too many acres. Some want a business. Others grow a bit of this and a bit of that with similar challenges,” Martha said.

They choose cultivars that look promising for the area and grow these trees by best practice methods with lots of record keeping. Darrell’s spreadsheets show when trees were planted, seasonal growth and comments, soil amendments, new grafts and production.

“I tell Darrell that God can’t take him home quite yet because I don’t understand these spreadsheets,” she said.

Learning Curve

Ausborns are somewhat like other growers trialing new crops that haven’t been grown in this area. They are concerned with climate, soil acidity or pH, adequate water, disease resistance, and cultivars suitable to the location.

Darrell tested their soil pH and found it to be about 6.8, which is less alkaline than some sites in the area. (7.0 is neutral.) He chooses tree cultivars that can tolerate neutral to slightly basic to slightly alkaline soils.

They water trees with a 200-gallon water tank behind a tractor. Trees are planted in full sun. One orchard is inter-planted in a redcedar-ash cover with full to partial sunlight.  Mowing and weed whacking around trees are among many tasks that fill a day and keep them both busy. Protecting trees from deer is necessary.

“We put up steel fence posts around the tree with the bumps facing out. Deer like to rub their antlers on the smooth bark of young trees. This discourages deer from rubbing. One inch hex wire (chicken wire) and bird netting are inexpensive materials that we put (around the posts).” There is space at the bottom to allow weed whacking. It keeps deer from rubbing but they still nibble leaves. They prune whatever is 4-5 ft. high,” he said.

Ausborns established a “nursery” or place where you keep small plants tended with extra care as they adjust to new area.  Confined space makes tree maintenance easier. They converted fenced garden space by a water tap for the nursery.

“It’s the way to go. Some of the tree stock we get is very small. It doesn’t survive well unless you put it in a nursery for a year or two and water it and weed it.”

Young trees die for many reasons. Cost of replacing them is an issue, besides the lost time until the tree is ready to pollinate. Grafting and layering are two techniques Darrell applies for obtaining new trees and restoring damaged ones. In this example the English walnut scion is grafted to hardy black walnut rootstock.

He finds a hardy compatible rootstock and picks a young pecan cultivar (scion), for example, to attach to it. He gives this grafted tree extra care in the nursery until it is transplanted. With this method he can grow new trees on established rootstock and restore some damaged trees. Shortening time to productivity is a goal. By using established rootstock, the tree should pollinate sooner than on its own roots.

He found a way to make more hazelnut trees from a parent tree by “layering.”

“Replacement hazelnut trees cost $10 – $20 a piece. On the Internet I saw where you layer it. You take a year old shoot, bend it and score it to the cambium and apply rooting compound and bury this branch. Next spring when I come back, the branch should be rooted,” he said. He puts the new plant in the nursery and if all goes well, he’ll have a second tree with the same genetic material.

Mature black walnut trees produced when Ausborns moved here. They’re in enough production that Darrell wanted to find a way to get nutmeats more easily.

“This corn sheller cost $15 at a farm auction. You put the black walnuts in here and turn the hand crank. It breaks up the husks. We rub the walnuts with rubber gloves to clean them and put them into this cage where we wash them with a hose. We dry them in a burlap bag and use a drill cracker to break them apart,” he said about their first nuts in ample harvest.

Prospects

Hazelnuts look promising for Ausborns. Shrubs were planted in 2008 and this is their first year to bear nuts. A big gamble for nut growers is the length of time it takes to choose viable options and then grow the promising plants until they fruit to see productivity at this site.

“I have counted these clusters (early August) and provided a squirrel doesn’t make off with them, we could get about 200. For us, it’s a joy to get 20,” she said.

”We’re doing trial planting. If it works, it will be someone else that takes it to an agricultural state,” he said. Hazelnuts come in shrub and tree forms. Some of their shrubs come from University of Nebraska-Lincoln, Arbor Day nursery, Minnesota, and some from Ontario, Canada.

“I read in the literature that deer don’t bother hazelnuts. I took the fence down. In ten days, I put it back up,” Darrell said. He installs a 6 ft. fence with chicken wire at the bottom to exclude rabbits who eat young shoots.

At their last regional nut growers meeting in La Crosse, Wisconsin, Ausborns saw small operation growers such as themselves with mechanical pickers. Hand picking becomes difficult. Seeing ingenuity for specialty nut harvest encourages them.

Chinese chestnut trees have also produced nuts on site. “We have been getting about two dozen nuts a year. With the burr they are about the size of a tennis ball,” he said. “We planted five nuts last fall and got five new plants.” Some are growing here.

Chinese chestnuts require 5.5 – 6.5 soil pH. He amends the soil with sulfur around the Chinese chestnut trees and has achieved 5.5 pH after several years. “I amend with sulfur and when I fertilize, I use a nitrogen fertilizer with high sulfur content,” he said.

Darrell picks up incidental information about nut trees. He’s aware of American chestnut blight and insects that will feed on Chinese chestnuts.  Once the nuts drop, they need to be refrigerated. Some grocery stores carry Chinese chestnuts for roasting in winter. Ausborns have roasted some too.

Pecans trees have grown here since 2008. Darrell plants northern varieties in clusters of a kind for cross-pollination. Pecans require about 6.5 pH soil, close to their land’s natural pH of soil.

He plans to bark graft poorly growing pecan trees to a different cultivar. If a graft can take, it offsets some costs and the established roots help shorten the time to production.

“To change a pecan cultivar, I put scions on either side, then will pick the one that grows the best,” he said.

“Some varieties are prone to leaf scab,” he said. Darrell has learned a lot about possible tree pests, tree life cycles, how varieties pollinate and produce nuts. This is part of his dream to learn about trees he grows.

“Forestry is the only thing I know,” he said. “A lot of my career, I worked with Native Americans who have a “Seven Generation” philosophy. Three generations before you, your generation, and three generations after you. I don’t know what will happen here when we can no longer work. Maybe it will go on in the family. I think people have to look into the future and present something that will be beneficial to our grandchildren and great grandchildren. In my work you have to think ahead 15 or 20 years.”

Trees don’t grow fast. It’s all about finding the right trees that will grow here, produce, and tolerate diseases and pests. If Ausborns thought of a specialty nut tree business at first, then this long process could wear them down. But when they compare notes at regional meetings, they see others with a small acreage and similar dreams. In the meantime, Darrell has learned a lot. His father thinks this work fits with his career.

“I might still be at it if there were more forestry possibilities in the area. But this has kept us busy. You have only so much time. I enjoy this, “ Darrell said.

Darrell mentioned that he has noticed other edge-of-zone trees growing around Yankton. He wonders if the years of Gurney Seed & Nursery had an influence on local people trying out plants that are not known to grow here. He’s interested in visiting with others that want to talk about dreams like his.