Incarvillea are hardy perennials that grow in clumps and range in height from 30 to 120 cm (1 to 4 feet). They are native to the high mountains of central and Eastern Asia.
They have fern-like leaves and carry exotic trumpet shaped flowers of yellow, red or pink.
They are great plants for use in borders, and the smaller varieties are of use in rock gardens.
Some of the common names for Incarvillea are trumpet flower, Hardy Gloxina, and Chinese trumpet flower.
Incarvillea sinesis, comonly known as Fern-leaved Trumpet Flower
Incarvillea arguta, commonly known as Himalayan Gloxinia
There are 16 members of the Incarvillea genus, these are widely known as Perennial Trumpet flowers. Some of the ones that are commonly grown in gardens include:
Incarvillea delavayi : Garden Gloxinia / Delavays Trumpet Flower
Incarvillea arguta : Himalayan Gloxinia
Incarvillea compacta : Dwarf Trumpet Flower
Incarvillea olgae : Princess' Trumpet Flower
Incarvillea sinensis (syn. Incarvillea Variabilis) : Fern-leaved Trumpet Flower
Incarvillea lutea : Yellow Colicroot
The rest of the genus is made up by:
Incarvillea altissima : Forest
Incarvillea beresowskii : Batalin
Incarvillea emodi : Chatterjee
Incarvillea younghusbandii: Short plant with large pink trumpet flowers discovered in Tibet by Captain Younghusband.
Incarvillea zhongdianensis : Grey-Wilson, a good rock garden plant.
Common Names: Hardy Gloxinia, Chinese Trumpet Flower, Trumpet Flower.
Life Cycle: Hardy perennial.
Height: 12 to 48 inches (30 to 120 cm).
Growing Region: Zones 3 to 8.
Flowers: Middle of spring and through summer.
Flower Details: Red, Pink, Magenta. Yellow throats. Trumpets. Blooms appear before foliage.
Foliage: Herbaceous. Dark Green. Divided. Ovate. Fern-like. Lanceolate.
Sow Outside: Surface. Start of spring - before the last frost, or early in autumn. Spacing 8 to 24 inches (20 to 60 cm).
Sow Inside: Germination time: one to two months. Temperature: 60 to 70°F (16 to 21°C). Two months in advance. Transplant the seedlings to their final location following the last frost.
Requirements and care: Full sunlight or afternoon shade in hot areas. pH 6.0 to 7.0. Sandy soil. Moist soil. Rich Soil. Regular watering during periods of growth to maintain soil moisture. Deadhead. Winter mulch in cold areas. Protect from slugs. Propagate: by dividing in the spring; avoid damaging the taproot.
The seeds of trumpet flower (Incarvillea pants) should be sown on the surface either before the last frost of spring or in the autumn. Incarvillea members like to grow in sunny area of the garden, and will not tolerate high humidity. Trumpet flowers have a preference for soils that are of a sandy nature, with a slightly acidic rich growth medium.
If you prefer to first grow Incarvillea indoors then they should be started about two months before the expected last frost of spring. They will take about three to eight weeks to germinate at a temperature of 15 to 21 degrees Celsius. Once you have trumpet flower (Incarvillea) seedlings transplant them at 25 cm (small species) to 50 cm apart (large).
Once growing it is fairly easy to look after Trumpet flowers, the soil should be kept moist and the plants dead headed following flowering. if you live in a cold area then it is necessary to provide a mulch to Incarvillea for the winter. If you require more Incarvillea plants then divide the plants in spring.
Incarvillea delavayi (Garden Gloxinia / Delavays Trumpet Flower / Chinese Trumpet Flower)
Larger Pink trumpet like flowers that look similar to Gloxinia, hence the common name. The flowers are fragrant and attract butterflies and bees.
Can grow in both acidic and alkaline soils, but prefers a range of 6 to 8 for best results. Full grown plants can reach 60cm (2 feet) in height, and should be spaced at around 30 to 40cm apart (1 to 1.4 feet).
Best grown in zones 6 to 10, though has been seen to be successful in zones 3 to 10.
Difficult to grow in areas that have summers that are hot and humid. Requires excellent drainage, and is therefore recommended as a plant for growing in a rock garden, or possibly on a raised bed.
Incarvillea arguta ( Himalayan Gloxinia)
Flowers can be pink or white, reaches from 45 to 60cm in height and should be sown with a spacing of about 30 to 40cm.
Best grown in sunny conditions, ideal for clay soils with excellent drainage. Grows in zones 7 to 10. Will attract hummingbirds if they are in your area.
I hope that you enjoyed this guide on how to grow Incarvillea plants. Updated September 2020.