Mine is around 18-20" and has stayed red, but what I've been waiting on is for it to branch, I might have to prune it. As for growth, I don't have the green trigona to compare it to. My plant is under a full spectrum led, which encourages red coloring. I'm not sure if it's still red because of the light or because that's typical of this species.

While I appreciate your reply, im afraid that a half meter plant is pretty far from adulthood( they can reach 1,5meters/5feet and still be juvenile)...... As for the led lights, well, i was hoping to hear of care in more natural conditions.....

As for the later part, "natural" trigona is fully green, and often without leaves.... where as numerous red cultivars exist in cultivation.... so im asking whether or not those "really red" cultivars end looking "less red" or ones that are "less red" by default end up completely green. Also, whether or not a "really red" , a "less red" and a green one have different growth speeds, due to possible difference in chlorophyll content.

Im also curious whether some cultivars keep their leaves on longer...

Also , just to slightly tweak the question - does leaf color stay red, even though the stem stays green?

So... its true....only the leaves stay red....

My red trigona grew to over 1.5m before it collapsed and I had to take cuttings to keep it alive. Most cuttings continued to grow red but some reverted to green. The piece I have remaining is now over 1m tall and is a mixture of mainly red but with some new branches green with green leaves. The bottom part is all red with red leaves.

So, when its propagated it looses its redness too..

Mine stays red only if in full sun. During the winter months I cut back on watering and it loses it's red leaves and sleeps. Turning more green-red. Back in late spring when I return it outside all new growth is red again.