How to Grow Mandevilla Vines
I worked as a gardener one summer and was surprised when I was asked to plant mandevilla vines. I knew that they were tropical, but would they grow here in NJ? Yes, because they love our hot, humid summers. We just have to grow them as annuals or bring them indoors because they cannot survive our winters.
What are Mandevilla Vines?
Mandevilla vines (Mandevilla spp.) is a genus of tropical flowering vines that are native to the southwestern US, Central and South America and the West Indies. They are characterized by their large colorful flowers which can be yellow, red, white or pink. The vines can grow to 20 feet in length so they are usually grown on a wall or a trellis.
Mandevillas are only hardy in zones 9 and 10. Gardeners in cooler climates either grow them as annuals or bring their vines indoors during the winter.
What is the Difference Between Dipladenia and Mandevilla Vines?
Dipladenia is a species of mandevilla. It grows in a mounding habit rather than as a vine. Dipladenia work well in containers or hanging baskets since they do not vine or require support. The flowers are similar but the leaves are smaller than mandevilla vines.
How to Grow Mandevilla Vines
Mandevillas need warm temperatures and lots of humidity. They prefer warm nights, 65⁰F - 70⁰F but will tolerate night time temperatures as low as 50⁰F. Give your vines a good misting every day to create the humidity that they crave.
The vines grow best in full sun which is a minimum of 6 to 8 hours of sunlight each day. They will tolerate a little shade but don’t flower as well. They need moist, well-drained soil. Try adding some sand, especially if you have clay soil.
Your vines will grow better if you fertilize them. Use a 10-20-10 to encourage flower production. You can use a time release fertilizer that will last all summer or you can feed your plants every 2 weeks during the growing season.
How to Prune Mandevilla Vines
You can prune your vine any time during the growing season to prevent it from becoming too unwieldy. Pruning also encourages your vine to become more bushy.
If you live in a tropical area and grow your vines in the ground, you can prune back your vines in the spring. Cut back any older stems to encourage new growth. Remove any stems that are too crowded. This will keep your vine healthy. You can also remove some of the length of your vine if it is getting too long.
How to Grow Mandevilla Vines in a Container
Most gardeners grow their mandevilla vines in containers so that they can easily bring them indoors during the winter. Don’t forget to install a trellis in your container for your vine to climb. It’s best to do this while you are filling the container with soil prior to planting your vine. If you wait until after you have planted your vine, you risk injuring or breaking the roots when you try to push the trellis into the soil.
Use a container that is wider than it is deep. Mandevilla roots tend to grow more horizontally than vertically. Regular potting soil is fine to use, especially if it contains time release fertilizer. Your vines will need regular fertilizing during the growing season so using a time release fertilizer is easier than having to remember to fertilize them every two weeks.
Be prepared to water your container a lot, especially in hot weather. Containers dry out quicker than your garden because they hold less soil. The soil should be moist but not soaking wet. Check it every day until you get a feel for how often to water.
How to Bring a Mandevilla Vine Indoors for the Winter
When night time temperatures drop below 50⁰F it’s time to bring your vine indoors. You will want to place it in the sunniest room in your house. It is normal for the vines to drop a lot of leaves when they are first brought inside. That is your plant adjusting the lower light levels indoors. You can help your plant by doing a light pruning after you have brought it indoors. This will encourage the plant to push out new growth that is better suited to indoor life.
There is no need to fertilize your plant during the winter. You want it to rest during the winter. Keep watering it. You may find that it doesn’t need to be watered as often indoors as outdoors.
Humidity is very important during the winter. Our homes are very dry because we don’t want mold growing anywhere. You will need to provide humidity for your plant either be misting it every day or by constructing a humidity tray. A humidity tray is a shallow tray that is filled with ornamental gravel (not the gravel from your driveway!). Add water to the tray. Place your container on top of the gravel, not in it. As the water evaporates from the tray, it creates constant humidity for you plant. Don’t forget to refill the tray with water when it dries out!
You can move your vine back outdoors in the spring when night time temperatures are consistently above 50⁰F.
How to Grow a Mandevilla Vine From a Cutting
The best time to take a cutting from your vine is in the spring when the vine is actively growing. Make a 4 to 6 inch cutting and strip the leaves from the lower half of your cutting. Dip the cut end in some rooting hormone to hasten root formation. Then push the lower half of your cutting into a container that is filled with premoistened soil.
Place a plastic bag over the container to create a humid environment and place it in a sunny window. Check the soil periodically to make sure that it is moist. You may have to add water to prevent the soil from drying out.
New roots should grow in 1 to 2 months. You will know that roots have formed when your plant starts growing new leaves. Plants that don’t have roots can’t make new leaves.
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