No Mandevilla Flowers: Getting A Mandevilla Plant To Bloom

By: Bonnie L. Grant, Certified Urban Agriculturist

Vibrant pink blooms and elegant vining stems characterize the mandevilla plant. Getting a mandevilla plant to bloom in tropical to sub-tropical regions relies upon plenty of water and adequate sunshine. In cooler climates, the plant is only suitable for summer outdoor growing and may need a bit more babying as the season is short and the vines need to mature before blooming. There are a few tricks you can try if there are no mandevilla flowers on your plant.

Mandevilla plants need nighttime temperatures of around 60 F. (15 C.) to force blooming. They cannot tolerate cooler temperatures of less than 40 F. (4 C.) and an outright freeze will kill the vine. Northern gardeners who wonder, “Why won’t my mandevilla bloom” may be in for some serious work to encourage this tropical wonder to brighten their landscape.

Why Won’t My Mandevilla Bloom?

Mandevilla are heavy bloomers in the right conditions. You can even prune them to the ground in late winter or early spring, and the plant will grow back quickly and reward you with the astounding blooms on the new vines.

If there are no mandevilla flowers on your plant, the cause could be cultural, improper site conditions or temperatures that are too cool. Established plants that are mature will provide the best color display, so don’t give up on young plants. They may simply need more time to bring out their flower show.

Cultural Reasons for a Mandevilla Not Flowering

These lovely plants need well drained soil with plenty of humus added. Indoor plants thrive in a mixture of peat, potting soil and fine sand. Potted plants should be fertilized every two weeks with a high phosphorus plant food from spring through summer. Feed outdoor plants with a time release bloom food in early spring. Avoid high nitrogen plant foods, as they fuel leaf and vine growth but do not promote flowers.

Provide a support for the vines so the buds can receive plenty of sunlight. Temperatures cannot be too warm, but situate the plants where there is protection from the searing heat during the hottest part of the day. Keep the fast growing vine deeply watered but not soggy. Following these guidelines will generally prevent a mandevilla not flowering.

Getting a Mandevilla Plant to Bloom

If you followed correct cultural care and siting, there is little reason a mandevilla plant does not bloom. However, in the rare cases where your vine just simply won’t produce, you can force it to flower. Use a teaspoon (5 ml.) of Epsom salts dissolved in water once every two weeks for a month. The salt content will build up in the soil if you try this for any longer. The magnesium in the Epsom salts should get it flowering again. In potted plants, leach the soil with plenty of water after trying this treatment.

Additionally, a mandevilla plant does not bloom if it hasn’t been trained correctly. In young plants, pinch off the new growth to promote side shoots. Mandevilla bloom off of new growth so this may be just the trick to get new vines and enhance blooming.

This article was last updated on

Read more about Mandevilla

Sick Mandevilla Plant

Related Articles

Flowering mandevilla vines (Mandevilla spp.) grow in the warm climates of U.S. Department of Agriculture plant hardiness zones 9 through 11. They are not highly susceptible to diseases, but insects may attack them. If your mandevilla plant is sick, insects may be the cause, but growing conditions could also be a problem. The right amount of sun and water, paired with the right temperatures, will result in a healthier mandevilla which will be better able to withstand insect infestations and recover with little damage.

How to Decorate Using Mandevilla

After you've gotten the hang of growing a mandevilla, you might decide you want to bring some of those beautiful blooms inside. According to Michelle Edgemont, owner of Michelle Edgemont Design, you can cut a few flower stems off every once and a while to decorate your home. "The stems are thin and wild," she says. "Style them in a trio of bud vases on your dining room table." If you have an area with some height, you can cut the stems longer to create a draping effect (like off the corner of your mantel). Have a small space? Edgemont says you can snip some blooms to add a bright pop of color to a powder room sink, or other small area. "If the cutting starts to root, you can transplant them into a pot with soil," she says. "Place in a sunny spot outdoors near a rail for it to climb."

Growing Mandevilla Vines Indoors

Mendevilla plants are gorgeous vines known for their lush flowers. Many people like to grow them on their balconies and patios. However, it is not always possible to grow your Mandevilla outdoors. These are not winter-hardy plants so they need warm temperatures to thrive.

Mandevilla vines require temperatures of at least 50 degrees F (10 degrees C) to thrive. It means that you cannot grow them outdoors yearlong unless you live in a warm climate. Most of the United States is not hot enough for this. It means that you will probably need to take your Mandevilla plant indoor for the winter or to grow it indoors for the whole year.

How to Grow Mandevilla Plant Indoors?

Mandevilla plants are not difficult to grow indoors, but you need to follow some guidelines. First of all, keep in mind that Mandevilla vine can take up some space. In the nature, these plants can grow up to 30 feet in height and length. Most houseplants don’t grow that big but they do take some space. Keep this in mind when deciding to grow Mandevillas indoors.

You will need to take your Mandevilla vine inside before the temperatures go lower than 50 degrees F. Take your plant inside and give it plenty of space. It is important to keep your Mandevilla in a room that is warmer than 60 degrees F.

Before you take your Mandevilla inside, make sure it’s free of pests. In case there are some pests, you need to get rid of them before you take your Mandevilla vine inside.

Another good practice before taking your vine indoors is to cut the plant by one third. In case your Mandevilla is too big, you can also trim it so it can fit the room without taking too much space.

If you have a greenhouse or a similar environment, perfect. This is ideal growing condition for your Mandevilla during winter. However, you may also place your plant near a sunny window, just make sure you can provide some shade for it. It is important to place your Mandevilla somewhere where it can get bright indirect light. Make sure to water it when the soil feels dry to the touch.

It is important to provide adequate light for your Mandevilla. Outdoors, they need regular fertilizing and watering. However, Mandevillas are dormant in winter so you should not worry about that. You need to cut watering in half during the dormant period. It is important that your Mandevilla stays relatively dry during this period to prevent rotting.

You may notice that your Mandevilla loses some of its leaves during winter. This is normal and it will regrow the leaves in spring, once the air warms up.

Your Mandevilla will probably not flower when it’s placed indoors. Making your vine bloom requires too much artificial light so it may not be worth it. Plus, remember that your Mandevilla is dormant during winter so you should not disturb this natural process.

In the Spring

Once the temperatures rise above 50 degrees F (10 degrees C) in the spring you can move your vine back outside. Before you move your Mandevilla to the patio or balcony make sure to remove any dead leaves. Your Mandevilla plant will thrive outdoors through the summer.

You should notice that your Mandevilla develops sprouts in early spring. This is the sign that you should move it to a sunny location and, if conditions and temperatures allow, to the balcony or patio. Make sure to start fertilizing your Mandevilla every two weeks to make it thrive. Use high phosphorous plant food for fertilizing. This is a great way to make your Mandevilla grow even stronger and to produce beautiful flowers.

How to Fertilize Mandevilla Plants?

Many people who grow Mandevilla vines want to know about the proper fertilizing routine. What do these beautiful vines need to thrive? Fertilizing Mandevilla plants is not difficult but you need to provide them with all the nutrients they need. This is the only way to make your Mandevilla vine bloom.

Mandevilla Flowering

Mandevilla vines are known for their lush, beautiful flowers. These plants belong to the Periwinkle family of sub-tropical flowering vines and bushes. They need warm temperatures to thrive and produce flowers.

In the US, Mandevillas can grow outdoors in the hardiness zones 9 to 11. However, they cannot grow outside in colder zones, so this is something to keep in mind. You need to know how to care for them in winter and how to provide adequate fertilizing routine to make them produce flowers and bloom the best they can.

Providing proper feeding to your Mandevilla will make it grow healthy and produce gorgeous blooms. Keep in mind that it’s not enough to simply fertilize – you need to understand the needs of your plant and to give it proper nutrients. This is why it’s crucial to choose proper fertilizer and to apply it adequately.

Good fertilizer will also ensure that your Mandevilla grows healthy into the next year. It is therefore important to follow fertilizer guidelines carefully and to give your Mandevilla vine just what it needs.

When to Fertilize Mandevillas?

Mandevillas are dormant in winter so you should never fertilize them during this period of time. You should fertilize your vine during its growing season, which is spring and summer. It is important to give fertilizer to your Mandevilla every two weeks during spring and summer.

It is important to stop fertilizing sometime in the fall, when the weather gets cold and your plant becomes dormant. If you continue applying fertilizer in winter it will make your plant develop new growth, which can be harmed by the cold.

Fertilizing should always follow the increased watering. If your Mandevilla was left indoors during winter you need to introduce it to the sunlight and outdoor conditions before you start fertilizing. Give your vine a chance to acclimate before you introduce fertilizer. Also, make sure that the frost has passed before you move your Mandevilla plant outdoors.

You may take your Mandevilla outside around March (in warmer zones) or April (in cooler zones). If you live in a very cold climate, you may even wait until May to take it outside.

You should start fertilizing in May. Young plants have a bit higher nitrogen ratio so you need to use a Mandevilla fertilizer on them to promote the growth of foliage. Feed your Mandevillas for two weeks and gradually move to balanced food that is intended to promote buds and flowering.

If you have potted Mandevillas, make sure to always use liquid fertilizer. After fertilizing, water your plant fully so the fertilizer can get to the roots and prevent them to burn.

On ground vines, use granulated time-release fertilizer. If you use this one you can apply fertilizer just once per month because the time-release fertilizers work slowly and release nutrients over longer period of time.

What Type of Fertilizer to Use?

Mandevillas need balanced fertilizer that will promote the growth of the plant and make it bloom. They respond well to diluted food you can add to their irrigation water two times per month.

Mandevilla plants benefit from 20-20-20 fertilizer that is also good for many other plant types. It’s advisable to use an organic fertilizer to help protect the environment.

If you wish to promote blooms, give your Mandevilla vine high phosphorus food every 2 to 3 weeks in the beginning of the flowering season. Phosphorus is great for promoting blooming and can help your vine flower.

If you are unsure about the phosphorus content, look at the formula. The middle number refers to phosphorus. Make sure that there is high phosphorus content in the formula. However, make sure not to go overboard – this can burn your plant.

Also, make sure to go back to more balanced fertilizer hallway through the summer. This is the best way to keep your Mandevilla plant strong and healthy.


Previous Article

Sprouting Avocado Pits: How To Root An Avocado Seed

Next Article

When to plant tomatoes in a greenhouse in Siberia and what can be planted together