I’m looking to get something edible on a black walnut and a Arizona walnut seedling. I’m not super familiar with walnuts. Our extension agency did some research on the Carpathian walnuts in the 1990s or 1980s and never got a harvest due to walnut blight. So I suspect I’m looking for something with resistance to that disease.
I’d also like something with edible, not too terribly difficult to crack nuts. The Arizona walnut is a small tree that makes pretty fall foliage in my part of Texas, but I’d like to grow something that has nuts that are worth the effort. The two varieties would need to pollinate each other.
It needs to be obtainable too. I found references to Howe walnuts, but haven’t seen a source.
Perhaps you’re aware that some walnut species are not graft compatible? It’s something to consider in your selection.
Walnut blight is a serious problem with some species as well. European walnut will not survive it without a spray regime – regardless of “resistance”. I use copper + manzate. The spray period is between harvest and Spring catkin fall.
Easy to crack walnuts make it easy for pests too. Consider your local population of squirrels, crows, etc.
Black walnuts are graft compatible but don’t tend to grow very well when on top of Juglans Microcarpa or Juglans Major. Most of the time, graft incompatibility is from cherry leaf roll virus infecting the graft where the rootstock gives a hypervirulent response which kills the graft.
IMO, if you want a walnut tree, start with a vigorous rootstock. Black walnut selections over the last 150 years amount to a few hundred varieties. For your area, Thomas, Neel #1, and Farrington would be good choices. I don’t have any Carpathian walnuts adapted to your region. John Brittain used to have several selections such as Allegheny.
Here is a list from nolinnursery 17 years ago. You might find some ideas from the varieties.
Juglans micropyla is graft compatible, but I forgot Arizona walnut isn’t microphyla. I will look into that.
Squirrels mysteriously disappear around here. Crows aren’t a major concern.
I’ll probably leave the Arizona walnut alone then, but I might still graft the black walnut seedling. Can black walnuts self pollinate? The tree I got the nuts from had no other black walnut nearby. I’d never seen a black walnut in the county before. It honestly didn’t look that healthy, but was large enough to be producing.
Walnut has the same reproductive system as pecan meaning protandrous and protogynous trees with some overlap between male/female flowers. So yes, it is possible to self-pollinate. It is most likely you have either Juglans Microcarpa or Juglans Major. Walnuts are all compatible for grafting, but some grafts may fail due to cherry leaf roll virus. Juglans Regia on Juglans Hindsii is an example where CLRV can kill the graft leaving the rootstock alive. It is also inadvisable to graft a large forest tree on smaller species. For example, using Juglans Major as a rootstock could cause problems because Juglans Regia scion over-grows the rootstock.
You could plant some seed nuts of a good variety and in 5 or 6 years it would start producing walnuts.
Nah, there is a definite foliage and walnut size difference between the two. The one I think is black walnut was in a yard too. The Arizona one isn’t microphyla either, the nut was too big, but not as big as the other.
…Pecans can self pollinate?
Microphyla is not a walnut species. Microcarpa is and is common in Texas. Black walnuts are a group of species in Juglans, see section Rhysocaryon. Juglans - Wikipedia
Yes, some pecan varieties can self-pollinate. It is usually protandrous varieties though a few protogynous varieties such as Mahan have been known to self-pollinate. See the pecan pollination spreadsheet for varieties that overlap. Pecan pollination chart If you can’t open the sheet, try pasting the URL direct into your browser. Filesize should be @1.3 MB. http://www.selectedplants.com/miscan/PecanPollination.xlsm
Creek, Jackson, Jubilee, and Davis are varieties noted for overlap.
Huh. We don’t grow those varieties here, so that’s probably why I had not heard of such a thing. That’s neat though.
Here is a list of all pecan varieties I know with at least 50% overlap of pollen shed with pistillate flower receptivity. Many others have a few days of overlap. I only have pollination data for about half of the varieties in my list. Western Schley is probably one grown in your area.
Baby B, Barton, Cape Fear, Cherokee, Cheyenne, Creek, Davis, Dooley, F. W. Anderson, Harris Super, Hastings, Jackson, Jubilee, Moore, Riverside, San Saba, Starking Hardy Giant, Summers, Syrup Mill, Western Schley, Williamson, Woodard