Modern Farmer – includes zone info
Small Footprint Family – good background and info, (n. america)
If you’re already growing perennial vegetables and want to take your garden or homestead to the next level, consider Permaculture gardening.
By imitating nature’s ecosystems, this approach promotes greater partnerships between plants, soil, insects and wildlife. In Permaculture designs, edible vegetables, herbs, fruiting shrubs and vines grow as an understory to taller fruit and nut trees. This technique is sometimes called “layering” or building a “guild.”
Layers or Guilds need to be built over a couple of years. In the first year, plant fruit trees as the outposts around your property. That same year and over the next several years, use sheet mulching to prepare planting areas beneath the trees for the understory plants. Sheet mulch a 2- to 3-foot-radius around each fruit tree the first year and gradually increase the mulched area as the trees grow.
Global inventory – info based
The Spruce.com – good roundup
Hardiness zone 6-10.
Mulching around fruit trees.