Family: Apocynaceae
Common Name: Rock Trumpet
Botanical Name: Mandevilla species
This fast-growing flowering vine is a must-have for adding soft white blooms to your outdoor rooms. These sun-loving tender perennials will bloom all summer long, showering you with their pearl-colored trumpet-shaped flowers. You can bring them inside when the temperatures drop below 50°F at night, and remember to trim them back and place them in a spot that receives over 6 hours of very bright indirect sunlight each day!
Keep the soil consistently moist during the growing season but remember to cut back on watering during the winter months. Mandevilla requires consistent fertilizing to help keep the flowers forming throughout the summer. Read more to learn how to grow these flowering shrubs indoors!
Light
The more light you can provide these flowering vines, the better. Try placing them in direct sunlight if possible to encourage them to bloom! South-facing windows are the ideal locations that will give them access to the light they require to pump out flower buds. Denying them more than 6 hours of the brightest indirect light will reduce flower production and cause the plant to become thin and leggy.
Water
Flowering plants like the mandevilla require constant watering. The soil should never be allowed to dry out completely as this can cause leaf and flower buds to drop. If you keep your mandevilla outdoors for the summer, you will be watering it daily as the warm temperatures and wind will dry out the soil faster than indoors! Keep an eye out for dry soil and water the soil slowly to give the soil time to absorb the moisture. Soak all soil areas evenly and make sure that all the water drains from the pot. The roots should never sit in a puddle of water as this will cause root rot.
Soil
It all starts and ends with the soil. Mandevilla growing in compacted and nutrient-poor soil doesn’t stand a chance! If you decide to transplant your Rock Trumpet (we do not recommend transplanting your new plants for at least 3-6 months after receiving them!) then please use a soil rich in organic matter that drains well but not excessively. The roots need time to absorb the moisture from the soil, but not so much time that the roots can drown! You can use any reputable soil mixture containing organic composted material and does not contain water-retentive crystals.
Temperature
The ideal temperatures for your mandevilla are between 70-80°F – they like it hot! The warmer it is, the more likely they will continue to bloom but beware of extreme periods of heat as this can dry out the soil very quickly! It is good to move it to a shady spot during heat waves to prevent excessive moisture loss! If you keep your mandevilla (or are considering) outside, make sure you bring it back inside before the nighttime temperatures drop below 50°F. If you keep it inside and the temperatures are over 75°F, ensure good air circulation around your plant. Stagnant air can be a breeding ground for bacteria and pests.
Humidity
Mandevilla loves moist air. If you can keep the humidity levels over 50% in the air space around it, all should be fine! Leaves that look brown around the edges are a good (or not so good) indication that your humidity levels are low!
Fertilizer
Yes, you should fertilize your mandevilla! Feed them a complete liquid fertilizer diluted to ¼ strength once a week. We recommend watering them first before you use a diluted liquid fertilizer. You can apply slow-release fertilizers or nutrient-rich compost at the beginning of the growing season! If you use a granular or compost fertilizer, water the plant after you have fertilized it.
Growth Rate
Mandevilla are fast-growing vines if grown in favorable environments (see above instructions!). They can reach 8’+ indoors depending on the light they receive. Feel free to prune them back to keep them from taking over your solarium!
Pet Friend or Foe
These plants are toxic to pets! Foe
Pro Tips
1. Rotate your mandevilla to give all sides equal access to the light.
2. If you are bringing your mandevilla back inside from a summer outing, then prune it back hard in the fall. Flowering plants need an adjustment period when you are drastically changing their environment!
3. If your plant isn’t thriving, try to flush the soil of possible salt and mineral build-up. Place the potted plant under running water for a few minutes as this will help leach out the excess minerals and salts!
4. Transplant your mandevilla every year to freshen up the soil and encourage it to grow larger.
5. If propagating is your thing, take cuttings from the hardwood, dust with a rooting hormone and keep the soil moist and warm. You can expect (fingers crossed) to see roots within 3-4 weeks!