BRTs are one of my favorites, I've been working on several for about 20 years , getting two that are in 15 and 25 gallon almost ready to put in a bonsai pot. I've set up a mist system to propagate cuttings on an industrial scale. I've set up a 120 volt 24 hr time clock that controls a 120 volt 10 minute clock that outputs the 120 volt to 24 volt that is connected to a 24 volt 3/4" 24 volt solenoid to the piping to the mist tables. I use 1.5" sixty cell trays, fill each tray with ProMix, 50% Canadian peat-50% perlite with mycorrhiza, $48 per 24" compressed cube. FOR BEST RESULTS, defoliate the branches to be used as cuttings, then wait until the dormant buds just start to swell, Then cut the twigs into about 3" long sections, I like to cut the bottom section just below the internode squarely, then apply 100% liquid Dip-N- Grow rooting hormone. Instead of pouring a small amount of the liquid into a shallow cup, my friend from Hawaii gave me two tiny plastic bottles that you get at a Vape Shop that have a short stainless steel 1/32" pipe with a cap on a plastic lanyard. Put some yellow electrician's tape on the bottle so you don't loose the bottle. Dip- Grow costs about $85.00 for 16 ounces, I can apply hormone to over 300 cuttings on less than a teaspoon, unused hormone in a cup should be discarded. TIMING IS MOST IMPORTANT, wait until Tax Day here in Palm Beach County when nighttime temperatures are between 80f to 85f. I set the timeclocks to operate from dawn to dusk energizing at least twice every ten minutes.
BRTs also can be air layered easily on branches over 3/8" i remove the bark equal minimum to the branch diameter, scrape it to the hard wood, then apply Dip-N-Grow to the top side of the cut, apply sphagnum moss soaked with Supervive and then wrap a double layer of heavy aluminum foil around the branch. I then wrap two pieces of 1mm bonsai wire on the top and bottom side of the aluminum foil. On bigger branches I cut a hole in the bottom of a gallon plastic pot equal to the diameter of the branch , screw 3 drywall screws into the area with the bark removed at a 120 degree spacing. In the heat of Aug and Sept roots will develop in about 3 weeks, these will be white roots, wait until these roots turn a little tan color, the white roots will break off very easily. I like to tease the sphagnum moss to spread out the roots radiating out from the stem. Very large branches can be rooted in summer in partial shade with rooting hormone with fair success. My good friend Allen Carver whose Grandfather Jim Moody operated Jupiter Bonsai gave me one of the original six seedlings from the seed his sister sent him from Brazil when he was liquidating Jupiter Bonsai last year, this tree was field grown. I pressure cleaned most all of its leaves, cut the tallest and widest branches to make it fit onto a 16' trailer. A Bobcat operater lifted it with a heavy sling, it cut several 3" branches to make it fit next to my kitchen window, this was July 2022. It never resprouted and the bark started pealing off. Around Christmas I started cutting off the dead branches- when I reduced it to 36" tall I noticed tiny sprouts on the shady side facing the house. I dug it out and put it in a 25 gallon Lerio using ProMix. It now looks like a Chia Pet, I've approach grafted a first branch and a new apex. This BRT is a different cultivar as most branches have no thorns and where they appear they are about 3/4" long and twice as fat as normal, it has a diameter at ground level of appox ten inches! I am using the same techniques for propigating Bucida spinosa, Dividivi, Lemon Eucalytpus, Neea buxifolia, Dwarf Podacarpus