I find Iowa State University as a good source of information on gardening. Several times Google referred to me articles from ISU. https://hortnews.extension.iastate.edu/spring-garden-tasks https://hortnews.extension.iastate.edu/your-complete-guide-pruning-trees-and-shrubs https://hortnews.extension.iastate.edu/2016/01-15/propagation.html

https://cdm21045.contentdm.oclc.org/digital/collection/coll13/search/searchterm/wurzelatlas%20mitteleuropaischer%20waldbaume%20und%20straucher/field/subcol/mode/exact/conn/and?fbclid=IwAR1ObUs1qo8IXx1V4mKpyQTpFeNJiRC3RMibHV3SZ1BGxyaBuzUdjtzLePY

https://www.instagram.com/p/CG8SbbDhgH0/?utm_source=ig_embed

http://www.decodays.ro/post/tuia-smaragd-crestere-plantare-preturi