protecting bougainvillea pot roots from freezing

Bougainvillea is extremely sensitive to freezing. If its branches are frost-damaged during overwintering but the roots are still healthy, it can send out new shoots again in early spring. However, if the roots are damaged by cold, the plant will truly be killed. Potted bougainvillea has a shallow layer of soil, so in cold winters its root system is very prone to freezing. So how should you go about protecting bougainvillea pot roots from freezing? Today, Lanyao will explain it all at once.

Table of Contents

3 Methods for Protecting Bougainvillea Pot Roots from Freezing

1. Move the Pot Indoors to Protect Roots from Freezing

For potted bougainvillea, if conditions allow in winter, move it indoors for overwintering. This is the least troublesome option. Watch the weather forecast, and move it indoors when the nighttime low is around 5°C (41°F) or below for two or three days in a row. For plants with flower buds or young seedlings, move them indoors when the nighttime low reaches 10°C (50°F).

Notes:

Before moving indoors, the potting soil must be on the dry side. If wet soil is brought into a poorly ventilated indoor environment, the stuffy, damp conditions are most likely to damage the roots. Do not prune heavily before bringing it indoors; only remove diseased and weak branches.

After bringing it indoors, place it in a spot with plenty of light. Provided there is ample light, if the ambient temperature can stay above 15°C (59°F), bougainvillea can continue to bloom.

2. Insulate the Pot to Keep Bougainvillea Roots from Freezing

If you really cannot move it indoors, then give the flowerpot a coat before the cold wave arrives.

Wrap the outside of the pot with a layer of bubble wrap or an old blanket for insulation. Raise the bottom of the pot so it is not directly against concrete. Then place it against a south-facing wall. The wall absorbs heat during the day and releases it at night, so it will not be as cold.

3. Build a Simple Shelter for Freeze Protection

In winter, build a temporary insulated plastic shelter. During the day it catches the sun, and the temperature inside rises. Before evening, cover the outside of the plastic shelter with felt cloth or cold-protection fabric to keep the temperature inside the shelter stable.

With this method, bougainvillea can maintain relatively good vigor in short periods of -10°C (14°F) conditions.

For bougainvillea planted in the ground, before a cold wave arrives you can spread 10–15 cm (4–6 inches) of fallen leaves or bark chips on the soil surface. This is like putting a quilt over the root system.

How to Judge Frost Damage and How to Rescue the Plant

Leave frost-damaged branches in place during winter; they can still shield the living tissue below from some of the cold. If you are not sure whether the plant is still alive, you can use your fingernail to scrape open the bark on a branch and check the color: if it is green when scraped, it is still alive; if the main trunk at the base is also dry and brown, it is basically dead from freezing, but there may still be surviving parts under the soil. It is best to wait until spring to see whether it can sprout before deciding whether to discard it.

For frost damage first aid, and to keep bougainvillea pot roots from freezing, remember three things:

1. First move it to a warm place.

First move it to a warm place around 10°C (50°F) to let it recover slowly. If the frost damage is not severe, it can recover.

2. Keep the potting soil on the dry side

Do not water for now. After frost damage, the roots hardly absorb water, so watering will instead cause rot.

3. Stop fertilizing and keep it warm

At low temperatures, stop all fertilizer. Wait until it has clearly resumed growth before considering fertilizing. If it loses all its leaves in winter, there is a 90% chance it is normal dormancy. If the bark scrapes green, do not throw it away.