Froze during cold spell, how do I prune the frozen leaves?
Trim away any damaged leaves with a knife or garden shears.
Here is a link with more information.
https://www.gardeningknowhow.com/ornamental/flowers/bop/bird-paradise-plant-freeze.htm
I was advised by a Lowes salesmen where I purchased several of these plants to add a half bag of palm fertilizer and it's now almost mid December. After doing some research online, I learned that this is not the time of year to fertilize this plant (even if it's now being transplanted from a pot). What should I do? I've already planted them according to the advice given but I can dig them up and remove the fertilizer if you think it's advisable to do so.
You can flush the area to help move the fertilizer out of the soil, but I would not dig up the plants again.
It does sound like a large amount of fertilizer (half of a bag). Always read the label and apply according to the package directions. A light amount is always safer then over fertilizing.
Some of the leaves have turned brown and dried out on the edges of the leaf. They are not old blooms, but the regular ones have dried areas around the outside of the leaf.
This condition is commonly called 'tipping' with Bird Of Paradise.
It can be caused by a number of factors including over watering, chemical burn from over fertilizing, root rot, and dry air (lack of humidity).
Using tap water can be an issue with the salts building up in the soil.
Leaving the water to sit for up to 48 hours before using it to water the plant with can help.
Here are some links to refresh you on the care requirements so you can make adjustments to the plant care.
https://www.gardeningknowhow.com/ornamental/flowers/bop/bird-of-paradise-an-exotic-flower-like-none-other.htm
https://www.gardeningknowhow.com/ornamental/flowers/bop/bird-of-paradise-pruning.htm
https://www.gardeningknowhow.com/ornamental/flowers/bop/bird-of-paradise-as-a-houseplant.htm
I see so many different size bushes of the same Mexican bird of paradise. Are there different species or is there a way to keep it smaller? Ours grows to 10 or 12 feet. Appreciate any info you may have.
There are 3 species in the family Fabaceae and genus Caesalpinia that go by the name bird of paradise.
Here is a link that will help you compare the sizes of each of these at mature age.
https://extension.arizona.edu/sites/extension.arizona.edu/files/pubs/az1634-2014.pdf
I have a bird of paradise bush and just recently a flower bloomed and it was two flowers on one stem. It certainly is beautiful, but I would like to know if this commonly occurs or is this somewhat rare?
Yes, this can occur quite often.
https://www.gardeningknowhow.com/ornamental/flowers/bop/bird-of-paradise-blooms.htm
I have a large bird of paradise which has a trunk about 20 ft high. I would like to cut it down to about 8-10 ft tall. Can I do this? Will it regenerate leaves at the cut off point? I live in San Clemente, Ca.
Yes, you can do severe pruning on a bird of paradise and cut back the branches and vertical growth by one half.
For more information on pruning birds of paradise, please visit the following link:
https://www.gardeningknowhow.com/ornamental/flowers/bop/bird-of-paradise-pruning.htm
When to plant a Mexican bird of paradise?
Mexican Bird Of Paradise likes to be planted in warm weather, so May thru September is a good planting period.
https://www.gardeningknowhow.com/ornamental/flowers/bop/mexican-red-bird-of-paradise.htm