in Las Vegas? I’ve read posts that say to water a lot and others that say don’t
water at all. Some say to drape frost
cloth or burlap directly over the plant and others say to put stakes in the
ground and don’t let the cloth/burlap touch the plant. Last winter 3 of our 4 plants (small ones)
survived, but it took a long time for them to come back. Right now they are beautifully pink and very
healthy.
post it on my blog very soon. So you are the lucky winner and I will soon post
your question and the answer I provide below! Bougainvillea will not tolerate
temperatures below freezing without some damage. The degree of damage will
depend on how much below freezing the temperature dropped and for how many hours and if there was wind
to go along with those low temperatures.
In order to answer this I want to explain a few things
about winter tender plants and how to manage them in general first before I
speak directly about bougainvillea. Winter tender plants should be
“hardened off” prior to freezing weather. This is by not fertilizing
this plant with nitrogen fertilizers a couple of months prior to freezing
temperatures and reducing the frequency of watering. In the Las Vegas valley freezing could be as soon as December 15 and,
rarely, even soon than this. So generally speaking do not fertilize ANY cold
sensitive, aka winter tender, freeze sensitive, frost sensitive, etc. plants
after mid September. Secondly, begin giving these plants less water to improve
their winter hardiness.
Those are the textbook answers. Actually holding back
on water is very difficult to do with automatic irrigation systems. You SHOULD
be cutting back on watering on all your plants in your landscape anyway at that time of year. The
easiest thing to do and most realistic is to stop applying fertilizer in late summer. When you
fertilize these plants and encourage growth late in the year they could push
new succulent growth which will be more easily damaged in freezes.
freeze that night and remove the covering in the morning a couple hours after the sun
comes up. If you use plastic, this plastic must also cover something that
releases heat back under the plastic. This can be a warm, south facing wall,
the soil beneath the plant, big jugs of water that was warmed during the day,
rabbits with their long warmth emitting ears, etc. Do not just wrap the plant
in plastic or it will freeze AND it may possibly get even colder
inside the plastic than the outside. Blame it on physics.
The other problem is wind. Cold and wind together are more
damaging than either alone. Try to keep the winter wind from the plant so an
enclosed courtyard, patio or other protected area of the yard is a good idea
for location for planting.
few extra degrees. Its root system will also be larger and capable of storing
more food. When freezing weather kills the top to the ground, the roots and
collar region will regenerate the top very quickly. Just give it lots of water
(bougainvillea likes deep watering) and fertilizer so it recovers quickly. If
temperatures drop to the teens it is possible you could lose the entire plant
so make sure the soil is mulched with several inches of wood or rock mulch to
insulate the roots and collar as much as possible and give it some extra protection.