After this winter I learned a lot about overwintering tropicals.  The  most important one was that it usually isn't the hard freeze that kills  plants but rather the constant cold temperatures, dry winds, drought  and disease making a bad situation worse.  Here are some more tips that  go beyond the obvious protection measures. 
1. Pay  Attention to the Watering Needs
Although succulents and  bromeliads like to be kept on the dry side,  many plants are left  without water when they need it most.  When plant's cells are ruptured  by frost, water evaporates from the damaged leaves quickly which means  that you have to keep them hydrated enough to heal.  Here in Florida its  rather dry in winter too, so plants that would otherwise survive a  freeze are often forgotten and die of drought.  You don't need to overdo  it, just make sure you don't forgo watering entirely during winter and  spring!
2.  Sanitize!
Plants are much more  susceptible to rotting in cold weather, so thoroughly clean your  pruning shears between plants when taking care of the cold damage.  I  even found cold hardy palms that suffered from rot transferred after  pruning rotting tender palms.  Even if there's no visible cold damage,  try spraying a fungicide around the crowns of your palms.
3.   Temporary Mulch.
Although all you need is a light covering of  mulch ordinarily, in winter it doesn't hurt to mound up some mulch at  the base of your more tender shrubs and perennials in the coldest  weather, spreading it back out afterward.  This prevents subsequent  disease by providing air circulation.  Light and fluffy pine straw works  wonders on smaller perrenials, and even kept christmas cactus, prayer  plant and rubber ficus going through the winter.  You can even stuff the  crown of your bromeliads, tree ferns or philodendrons on the coldest  nights!
4.  Pick Root Hardy Plants
Gingers,  and elephant ears are the easiest solution since they naturally store  their energy in enlarged fleshy rhizomes, practically leaping back out  of the ground in early spring!  There is a huge selection of unusual  choices, but my picks are crinums, blood lily, alpinias, alocasias and  plain old lily of the nile.  Many of these will actually retain foliage  in winter, but their huge and cold tolerant tubers will give you peace  of mind.
5.  Plant Densely
I know that all  the books tell you to give plants plenty of room, but if you're  experimenting with tropicals I've found its best to pack them in nice  and snug.  This gives a lot more frost protection, and also keeps the  cold winds from drying out the foliage.
For example, my shell  gingers (alpinia zerumbet "variegated) were younger plants spread out  with space between them.  After this winter all that was left above  ground were several stalks that remained protected by the taller ones.   Just a few miles away is a shopping center that retained shell gingers  up to 6 feet tall, all because the more mature specimens were tightly  packed.  Only the tallest stalks were damaged!
Here is my list of how everything did, updated today!
Hardiness  List and Damage Report
 

 
thanks for the tips, however some plants can't tolerate any bit of winter, they are going to die sure, my Hibiscus plants and Moringa oleifera and Mango tree are died during this winter. I don't know how to protect them.
ReplyDeleteInteresting that sanitizing is number two on your list. It's a great idea. I didn't know plants are more suceptible in the cold.
ReplyDeleteGood summary! Among the five, I did best is "plant densely". LOL. That is because I don't have much garden space, and when the plants were young, I always thought I can pack more into it. Maybe it will do something good the next winter, huh?
ReplyDeleteI will be ready for the next time cold will be here! I like it so much! Thanks.
ReplyDeleteI definitely like Tip #5. I'm learning by visiting old Florida gardens that crowding is okay in a tropical gardening. My plants are spaced way too liberally, I guess, as a result of living in Zone 7 for too long. One thing I'm hoping to do this summer is plug in a bunch of palm trees here and there, willy nilly. Also, next winter, I hope to acquire and experiment with FreezPruf. I had heard of the product last fall but never ordered any. It claims to add two or three degrees of warmth, which is really all we need, and one application supposedly lasts for several weeks.
ReplyDeleteGREAT post, Steve! I never thought about sanitizing between pruning when pruning rot...you bring up a fantastic point!
ReplyDeleteI, too, heard of FreezPruf, from my friends at Digthedirt.com. I'll definitely try it this year.
My firmly packed tropicals were the ones that made it, too. I believe in this method whole heartedly!