Hello Larry, 

I am glad to hear that after a few years your trees are doing well and adding deer protection is one important step to protect your trees. Unfortunately the American chestnut tree (Castaneda dentate) is still susceptible to the chestnut blight fungus. I found a similar question to yours that was answered by MSU’s chestnut expert Erin Lizotte, regarding the feasibility of growing the American Chestnut tree in northern Michigan. She explains the following:

 "Unfortunately, chestnut blight infects American chestnuts planted in our region. The trees you plant likely would not reach nut bearing maturity before dying back to the ground and then resprouting. This can be a really frustrating experience as trees often grow well for 10-20 years before collapsing. The sandy site conditions you listed are actually excellent for chestnuts, you would want to avoid the wet areas as they lead to root diseases in chestnuts. If you want to plant chestnuts for the cultural and wildlife value (not commercial production), you might consider Chinese chestnut seedlings. These are blight resistant and very affordable. They are more compact in nature so you won't get the majestic American chestnut canopy described in historical documents.

The American Chestnut Foundation continues to make strides towards developing a blight resistant American chestnut tree, but still does not have anything widely available to my knowledge. Efforts to restore the American chestnut to the landscape continue". (Erin Lizotte Replied March 10, 2021, 9:51 AM EST#737888)

According the American Chestnut Foundation (TACF), No species of chestnut is immune to blight, since all of them can get the disease. However, several species are resistant to the blight; they get the disease, but only mild cases. High levels of blight resistance are found in Asian species of chestnut, and the Chinese chestnut, C. mollissima, has the highest levels of resistance that have been measured.( Blight-Resistance.pdf (acf.org)

The best thing you can do to protect your trees is to keep them as healthy as possible. As you have done already, protecting them from wildlife and deer will prolong the life of your tree. Controlling deer early is important since Chestnut trees are often browsed by deer. Other measures you can take is to remove any competition for water and nutrients by eliminating weeds. Routinely monitor for pests and other diseases and water during drought conditions. All of these tasks will help with the success and life of your Chestnut trees.

For all the up to date information regarding care and the advancements in chestnut blight go to the website of the American Chestnut Foundation. The have a lot of resources and valuable information. I have included some articles that you may find beneficial. You may also want to sign up to receive their newsletters.

https://acf.org/

Growing-Chestnuts_Guide-to-Basics_FINAL1.pdf (acf.org)

Factsheet_HowToGrowChestnuts_2019.pdf (acf.org)

Identifying-Blight-Cankers.pdf (acf.org)

planting_manual.pub (acf.org)

MSU has a Chestnut website that is geared towards commercial growers but has valuable insect scouting reports that homeowners will find helpful on what/when pests are active and how to look for them .

MSU articles

Chestnuts (msu.edu)

Chestnut growing requirements factsheet.pub (msu.edu)

Michigan chestnut scouting report – June 10, 2020 - Chestnuts (msu.edu)

https://www.canr.msu.edu/uploads/234/70810/Chestnut_growing_requirements_factsheet.pdf

I hope all this information helps you out!  Thank you for contacting Ask Extension.