Black walnut update: Surprise!

 A chicken wire cage will protect the black walnut seedling from deer and rabbits.

Look what happens when you're not paying attention.

The background: We sowed 14 black walnuts in fall 2009. Three germinated. They were planted out back on the "nature trail" last fall. This spring, they looked good. We were hopeful. But then, nothing. Did a cold snap kill the buds? Who knows. There were too many other things to think about and we left the sad-looking stems alone. 

A couple of weeks ago we made the discovery. One of the seedling trees has put out a robust show of leaves. It lives!

Save the black walnuts

Someday, these three black walnut seedlings will be state park worthy. We planted them last fall -- they're still safe and snug under snow cover.

So, instead of focusing on issues such as creating jobs or designing a better tax system, some Minnesota legislators are pushing a bill requiring the DNR to cut and sell black walnut trees in two state parks to raise revenue.

What are they thinking? I don't see the point of cutting down trees that may be as old as a century or more for a cash infusion that really won't make much of a difference in the budget. The Austin Daily Herald calls the idea "wacky", and I have to agree.

Update: The Great Black Walnut Experiment

The black walnut seedlings were planted Sept. 7 to give them a chance to put down roots before winter. No soil amendments necessary.

Just barely up.

Last November we planted 14 pots of black walnuts. Having never tried to grow black walnuts before, we kept our expectations realistic. Information from the Extension Service suggested that maybe half (seven) would germinate. Well, we didn't hit the halfway mark, but we still feel pretty darn good that three did germinate.

Starting to flush.

None of the pots were coddled. They were left out in the snow and cold all winter to satisfy their stratification needs. As temperatures warmed in the spring, we checked to make sure the pots didn't dry out, but that was it. By the end of May you could see the seedlings -- hunched over but ready to pop and grow.

The three seedlings.

Black walnut (Juglans nigra) is interesting partly because it is an allelopathic plant. (Definition alert: Allelopathy refers to the ability of some plants to produce toxic substances that can affect other nearby plants. It's one way to beat competition for space, light, etc.) Black walnut produces juglone, a chemical that can be toxic to certain sensitive plants such as tomatoes. The West Virginia University Extension Service has a list of plants that are sensitive to juglone and some that are tolerant.

By July the three seedlings were green and sturdy. In September, they were ready for planting.

We chose sites back along the nature trail, put them in the ground and caged them to give them a better chance at survival. The rest is up to them.

Just planted on Sept. 7.

Now, the leaves have dropped and without the cage, you'd be hard-pressed to locate the seedling.

The great black walnut experiment is under way

Walnuts with their husks (hulls) are at top. They're about the size of a tennis ball. The hulled walnuts are at bottom.

I obviously have a lot to learn about black walnuts. For example, take this passage from the Minnesota State Extension Service: "Take care when hulling or shelling walnuts. The practice of driving over nuts with an automobile can be a dangerous one. Nuts and broken shells may be thrown into the air by the tires, possibly causing bodily injury or property damage."

Huh? Driving over walnuts with a car?!

Apparently, this is a fairly routine procedure for hulling if a quick google search is any indication of how prevalent the practice is. Walnuts deserve a lot more respect than I realized.

Nut trees have always seemed a little mysterious to me. Trees grown for fruit or shade were a part of my childhood, but nuts -- when we had them -- always came in a bag or a can from the grocery.

So I was excited when a package containing black walnut seeds arrived in the mail in October. Chrissy sent us black walnuts harvested in Michigan's Upper Peninsula. And it was a revelation to me that black walnuts had a husk that had to be removed. The husk can be used in making dye and there are lots of warnings to use heavy rubber gloves when handling them or risk stained hands for a long time.

Lucky for us, Chrissy sent us both hulled and unhulled nuts so we didn't have to back the Honda over the nuts and risk "bodily injury."

Checking for damage to the seed. The two floating at left were discarded.

But we did need to check the hulled nuts for insect damage or other injury before planting. That meant plunging them into a bucket of water. Floaters were no good and needed to be tossed (but not in the compost; walnuts contain juglone which can kill or stunt other plants). Those that sank were viable and good for planting.

The good seeds were planted in soilless mix in one-gallon nursery pots.

That gave us 14 nuts to pot and place in the cold frame. Walnuts need stratification (cold treatment) to germinate; we're going the natural route and just leaving them outside all winter.

Even though its nuts have good flavor, black walnut (Juglans nigra) is grown more for its lumber than for its nuts; English walnut (Juglans regia) is the one that's grown for commercial nut production because it's easier to harvest and crack.
 

The walnuts went into their pots Nov. 4. I'll report back in the spring.

The seeds were covered with a couple of inches of soilless mix, tagged and placed in the cold frame. Information from the Extension Service suggests we can expect maybe half to germinate. (These pots since have been covered with snow.) 

Details on growing and harvesting black walnut can be found here and here and here.