When establishing a new berm, it is imperative to get the bare soil covered as soon as possible to cut down on erosion from the elements. If you do nothing else, making sure that a pioneer species guild, preferably comprised of local species and preferably geared towards root mat growth and soil generation, is planted all over the berm will keep that berm looking bermy, rather than lumpy mud puddley.
I even mulch my berms with woodchips, and tarp them if the rain or wind is heavy. As soon as there is an established ground cover, the berm will be much more structurally stable.
The other concern when planting is ensuring that larger organisms have the footings they need to grow tall and withstand things like wind. That is why it is not recommended to grow trees on the top of a newly made berm, or for that matter, any berm not specifically designed to accomodate trees and their root zones, and incorporate them quickly into their structure.
A tree without sufficiently anchored roots will end up blowing over, likely taking the top of the berm with it.
I would be careful planting even large shrubs at the crown of the berm, but anything herbaceous, or any shrub with a profile unlikely to catch the wind, shouldn't be an issue. I would save larger trees for the feet of the berm, where they can both benefit from the added fertility (if it's anything like a hugelbeet) and water retention capacity of the berm, or even just benefit from it as a windbreak.
A human being should be able to change a diaper, plan an invasion, butcher a hog, conn a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects.
-Robert A. Heinlein
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