Any Walnut Tree Experts here?

I want to ask when the best time to graft English to black root stock is. Can I do it now. There are some donor English trees not far from me with suckers the appropriate size diam. Can I root from suckers?
This is old Santa Clara County, ie Silicon Valley orchard stock that is so rare to see I'd like to start some as a restoration/saving project. This valley used to be nothing but orchards. Pear, bing cherry, walnut, apricot. I drove by the donor trees, one of the four was cut down, fruit still in their husks... Arghhhh.
Jeff back to work before it goes to India.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
Add image file
Upload is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.