I Have a Mandevilla Plant That Suffered Frost Damage and It Looks Dead: Will It Come Back?

Answer

The magnificent trumpet-shaped blooms of mandevillas (Mandevilla spp.) come in a variety of colours including pink, yellow, red, and white, and they bloom constantly on the plant throughout the most of the growing season. These characteristics have made mandevillas a popular choice among gardeners. There are more than one hundred different species of mandevilla, as stated by the Clemson Cooperative Extension. These tropical plants may be grown as perennial vines in USDA plant hardiness zones 9 to 11, but they also have the ability to be farmed as annuals or overwintered indoors throughout a much wider range. The USDA plant hardiness zones are used to classify where plants can survive the winter.

Frosts and even lengthy periods with temperatures below 55 degrees Fahrenheit may cause damage to a mandevilla, and the extent of that damage can often be severe enough that it is unclear whether or not the plant has survived.

Tip

If your mandevilla was damaged by frost, you will need to examine the plant to establish whether or not it has really perished or if it is still capable of producing new growth.

Inspection and Immediate Action

Frost damage to a mandevilla may cause its flowers and foliage to fall off rather rapidly, but it may not be as simple to determine whether or not the plant’s stems have been spared. Use your fingernail or a clean, sharp knife to carefully scrape away a tiny bit of the stem’s outer bark. Then, look at the colour of the underlying tissue to determine whether or not the part of the stem that you are examining is still alive.

A portion of the plant is considered to be alive if its colour is green. The tissue is dead if it has a brown or black colour to it. Even though it needs less water than it did before it was injured and when it was actively growing, the mandevilla will still benefit from regular irrigation if it was not completely killed by the frost. If the frost did not completely kill the mandevilla, it will still benefit from regular irrigation.

If there is not enough rainfall, you should thoroughly irrigate the mandevilla so that the soil surrounding the plant’s roots does not ever get entirely dry. You should also do this anytime the soil a few inches below the surface of the soil around the base of the mandevilla feels dry to the touch.

Put off Pruning

It may be tempting to cut off dead sections of the mandevilla as soon as you assess the extent of the damage; however, the University of Florida IFAS Extension recommends waiting to clip off dead mandevilla stems until there is no longer any risk of additional cold harm. The fact that the dead parts are still linked to the plant provides some kind of protection against more cold harm. When you prune a plant too early, you might cause it to produce a flush of fragile new growth that is more susceptible to being damaged by any more cold weather.

Perform Corrective Pruning

If you have determined the general amount of the damage, or once new growth has begun to sprout and there is no longer any risk of cold damage, you may begin to cut away any areas of the mandevilla that are dead. Make angled cuts into the live, green tissue right above a bud, using pruning shears or loppers that are clean, sharp, and in good condition.

If it seems as if the mandevilla stems have been died back entirely, with no green tissue showing aboveground, trim the stems to a level that is about 6 inches above the ground. If the root system was able to endure the cold winter, there is still a chance that new growth may develop in a few months.

Prevent Future Problems

It is possible, through the implementation of specific maintenance procedures, to lessen the likelihood that the mandevilla will be harmed to the same extent in subsequent years, either in the event that the mandevilla lives or in the event that it does not and you choose to replace it with a different species of mandevilla. The temperature of the soil may be controlled by maintaining a layer of organic material mulch that is between three and four inches thick over the ground surrounding the mandevilla. This helps to keep the mandevilla roots and crown from being damaged.

According to the Arizona Cooperative Extension, you should make sure that the mandevilla gets enough hydration throughout the entire growth season, but you should cut down on the frequency of your waterings in the weeks preceding up to any potential cold events. In addition, fertiliser should not be applied to the mandevilla in the late autumn or early winter since doing so may result in the production of delicate new growth.