Re: Propagating arborvitae under lights The peat/perlite mix is very commonly used for many items. Has a nice balance of moisture and air, and the biggy is the light weight compared to anything with sand. I used straight sand myself, and it does work great for conifers. The drawback is the aforementioned weight...I have sturdy wooden trays made specially for this, but the plastic materials used in most nursery situations have a terrible time when being moved about with that heavy moist sand in them. So whichever should work fine, depending on what you have handy and works for your situation and equipment...again, arborvitae root very easily anyway so nothing to lose sleep over.
Re: Propagating arborvitae under lights If you use peat/perlite, the most common blends used for rooting cuttings are 50:50 or 65 percent perlite 35 percent peat. Sphagnum is the best type of peat to use. - Millet (1,425-)