Abies balsamea 'Nana', Abies balsamea 'Piccolo' are tiny firs, extremely cold-hardy and VERY slow growing (2-4" per year). Abies lasiacarpa 'Duflon' - again, extremely hardy and less than 1/2" growth per year.

Juniperus communis 'Miniature' - a juniper hardy to at least -20* and growing only 2-4" per year.

Picea abies 'Formanek' - 3-6", hardy to -30*, Picea abies 'Jessy', less than an inch/year and hardy to -30. Picea pungens 'Globe' and Picea pungens 'Lundeby's Dwarf, both hardy to -40* and about an inch per year.

Want more choices? ;o)

Al

Hey Al!
Since you are here leme ask:

This woodenbox is 3ft by 0.5ft wide. Fits in my window which is facing east here in my home in s.e.PA. Planning to put atleast one evergreen in middle , surrounded by annuals. In winter I may add ornamental cabbage, ivy etc.

Pls recommend some evergreen that looks great.. small, mounding/trailing and not pointing up. Green or yellowish is ok too..about less than a foot max in height.
I kinda liked Abies balsamea 'Piccolo' but is there any that is yellowish green?

Tks..

What about Juniperus procumbens 'nana'? Easy to find, genetically vigorous, hardy there w/o protection, mounding/trailing, responds well to pruning.

OH! I have lots of gorgeous Shimpaku junipers (J. chinensis 'Sargentii') I started from cuttings growing on for bonsai in my raised beds. I'd be happy to send you one. They can easily be trained to cascade & are easily pruned to a mound-shape. The procumbens trails/cascades and mounds naturally, though. Procumbens - light green, Shimpaku - dark green.

I have a really big (almost 10') Ficus b. to prune for a lady tonight before the Red Wings beat Chicago (again), but I'll try to get a couple of pics of the plant to share. I know you'll love it. It's probably THE most favored plant for bonsai because of its MANY attributes. It's not fussy, either. You'd just have to be sure you pair almost any evergreen with plants that don't like it too wet & use a fast soil.

Al