You Will Not Protect Bougainville from Freezing by Feeding Them

Q. Before the first freeze here in Las Vegas, probably in 3-1/2 weeks, what may I feed them?  Might there be something simple, without figuring amounts and all kinds of mixing? I have three plants, all in the ground.  They are six years old this year, and I wrap their bases before the freeze. They always come back come March/April, and bloom beautifully in August/September through October – when the real heat hits.

A. I like your idea of wrapping the bases of the plants before any freeze. Unless you have a very warm microclimate in your yard, and there are some of those in Las Vegas, you will see damage to them at the first light freeze with temperatures below 32° F. The harder the freeze and the longer it lasts, the more severe the damage.

Bougainvillea after freezing weather in Las Vegas

Wood mulches will also protect the base of bougainvillea but wrapping it is more effective. This way when it freezes it will kill the top of the bougainvillea to the top of the mulch or wrap and not any further.

Of course this works to temperatures below freezing for short periods of time. If the temperatures are extremely cold, or if these temperatures last a long time, then it will freeze the plant to the ground. How well you protect the base of the plant will determine how strong it will come back, or not, next spring. Having bougainvillea in a spot in the yard which does not have a lot of wind and is very close to a warm, South or even better yet, West-facing wall will improve its chances for survival.

Freeze damage hits the youngest and thinnest plant parts first during a light freeze and the part of the plant most exposed to wind and less protected by warm south or west facing walls

Plants that freeze to the ground will come back like gangbusters next spring because of their established root system. Plants that are first planted have to grow both the roots and the tops and so growth is divided between the two. Plants that have an established root system and freeze to the ground only have to grow the top back. So all of the spring growth is funneled to top growth so we see huge amounts of top growth in the spring.

Spring recover of oleander from a winter freeze

You do not want to feed them anything this time of year. Just make sure they get watered. This goes for any winter tender plant. These plants should get no fertilizer applied to them that promotes growth any time after mid-August. Fertilizers which stimulate new growth will cause the plant to become more succulent and lower its chances of surviving winter freezes. This is not true of plants that have no problem surviving winter freezes. In fact, those plants can receive mid fall applications of fertilizer with no problems. A mid fall application of fertilizer can substitute for a Spring application but not winter tender plants.