Bromeliads are mostly "apical dominent." That is, the bud on the main growing stem of the plant secretes an auxin which inhibits the buds on the same stem from growing. Although many Bromeliads don't look like it, they all have a stem, it is often just rather compact.
When the terminal bud changes from "growing" to "blooming" mode, the remaining buds are free to grow and they become the pups, offsets, ... There are a few monocarpic Bromeliads (that do not pup) but it is the exception rather than the rule. There are also some that produce just a single pup right next to the blooming scape (Guzmania sanguinea, Vriesea splendens, among others). These are tricky to propagate - one must be patient and careful. (We call these "upper-puppers.")
There are also the opposite types, like Neoregelia Fireball and many Bilbergias that seem to branch freely. Vive la difference!
Well, not really. If you've ever tried to take a pup from Vriesea splendens you would know just what I mean. The (almost always) lone pup comes up right in the middle and it's hard to get it apart without destroying the main plant. So, most people just leave them in place. After several generations though, the stem gets pretty gangly. If you are very careful and get just enough of the pup and the mother you can sometimes coerce additional pups.
There are really very few Bromeliads that die without pupping. I just think of the branch dying and being replaced by others. The most famous exception is the largest Bromeliad of all, the gigantic Puya raimondii from Peru and Bolivia.
I did have a georgeous Orthophytum naviodes that bloomed and died without pupping. I rather suspect it was just my non-ideal growing conditions (too cool in the Winter). All the other Orthophytums I grow branch freely.
We grow in a greenhouse with the approximate low setting of 54 degrees. It's about 20x30' facing south with two separate layers of poly. There are micro-climates inside that affect growth. The furnace end is a little warmer in the Winter; the air-inlet end is dryer in the Summer; the upper benches always warmer, etc. For most of them, 54 is sufficient but some of them aren't very happy.The warmer growers like the Brazilian Vrieseas seem to withstand colder temps than Vrieseas from Peru. Go figure.
Even though Bromeliads are mostly tropical, elevation plays a big part. High elevation dessert plants like Puyas (Peru, Bolivia) are frequently subjected to freezing temperatures and cope just fine. All things being equal, the temperature drops about 3.6 degrees for every 1,000 foot of elevation. So even at the equator it can be quite cool (like in Quito). It's often difficult to know what temperature a plant prefers. I just play around with the micro-climates in the greenhouse and the fussy ones just tend to slowly fade away and eventually die. They don't get replaced (well mostly...)
Very good ~ thank you. I was curious (knowing you get colder than us) how your Broms endured wintertime.
I've used a GH for 3 winters now and monitored the coolest temp end. I have noticed the microclimates in the GH. Mine is smaller ( yours appears huge) but I keep a thermometer on the heater end. Also one on the cool end that has a sensor that I can read in the house. That way I can see when I need to add wood to the heater.
I asked because I was not sure it this would be warm enough. While I was researching, I did find Brom survival rates by temperature but I know there are also variables. Again, thank you... Kristi