Streptocarpus is an Afrotropical genus in about 155 species of the flowering plants in the family Gesneriaceae. It is a popular house plant and is native to Afromontane biotopes from eastern, central, and South Africa, including the Comoro Islands and Madagascar.
It is also renowned as Cape primrose and nodding violet. The flower has five-petals, salverform tubes, looks like an orchid with 2.5 to 3.5 cm in diameter, and hover or arch over the plant.
It varies in limited colors like mid-purples, pale pinks, and white whereas, the leaves and stems are cauline. Birds, long-tongued flies, butterflies, moths, and bees can pollinate the flowers.
You can grow streptocarpus as houseplants, ornamental plants, hanging plants, and sometimes as bedding plants too.
Is streptocarpus annual or perennial?
Streptocarpus is an annual. Streptocarpus – botanists have found that this flowering plant is related to Viola and Dipladenia.
Though its flowers are iridescent, a streptocarpus’s blooms are much subtler than those of a viola or Dipladenia. This flower does not need full sun exposure and prefers moist, shady areas of the garden.
The best time to plant streps is in the winter months during fall. They will thrive in zones 3-9. The flower color of this houseplant is limited to mid-purples, pale pinks, and white.
How to Grow Streptocarpus Plant?
Generally, streptocarpus will bloom from spring to autumn as spring is their growing season, and they usually stop flowering and lose some leaves in winter whereas, some genus still produce flowers in winter as well.
You can grow or propagate this plant by seedlings, leaf, root plantlet, clump division, and by stem cuttings as well.
Germinate from seeds
- Thinly scatter the Cape primrose seeds on top of the potting mix and provide light to germinate.
- You should cover it in a clear plastic bag to keep up the humidity.
- Place the pot with facing window where it will get bright, indirect light, and maintain temperature about 18 to 20 degrees C (avoid direct sunlight).
Grow from leaf cuttings
- Take a single leaf, and pot it with the base down in a potting mix.
- Cover the seed pot with clear plastic and secure it with a rubber band to keep up the humidity. If you can change the water weekly, you can also put the leaves in a glass of water.
- Either you cut the leaf segments horizontally or length-wise across the leaf, both parts can be used as cutting to grow from it. These plant’s leaves contain a high concentration of cytokinin, which is a type of rooting hormone due to which it does not need artificial rooting hormone.
Grow from root plantlet
- Un-pot a plant from which you want to produce root plantlets.
- You can see the roots exposed, either in the soil, between the pots, or coming out through the bottom holes of the pot.
- Snip those plantlets off with their attached roots, and plant up.
To grow from clump division
- Divide a multi-crown clump into different pieces along with their root system, and plant up as for leaf propagation.
To grow from stem cuttings
- Take a cutting of about 5 to 10 cm beneath a leaf node.
- Place the cutting in clean water until it sprouts its roots
- Now put the cuttings in bright but indirect light at about 18 to 20 degrees Celsius.
- Observe the roots, and if they are 5 cm long, you can grow up the cutting into the soil mixture.
How do you care for streptocarpus?
After planting, maintain the soil’s moisture. Most varieties bloom from spring to early summer. Flowers will fade in about ten days in hot, dry weather and can be overwatered.
Misting is a good care technique when growing only a few plants that won’t be cut back by overgrazing. How do you water streptocarpus?
Watering
during the growing season should be light with deep watering at night (especially in dry sun climates) or with a soaker hose around the outside of the pots and soil.
The idea is to moisten the soil while avoiding wetting the leaves. This reduces leaf diseases and prevents shocking the plants.
Watering during fall and winter should be reduced or stopped completely, allowing the plants to rest and store energy for spring growth.
How do you feed streptocarpus?
Feeding is usually not necessary since most of these native soils are high in organic content. Applying a slow-release granular, complete fertilizer in late August will encourage early bloomings with new growth in spring.
If you wish to dose, all-purpose fertilizer at ½- to ¾-inch (1.25–1.75 cm) deep per plant will provide adequate nutrition for a relatively long season.
Do you prune streptocarpus?
Yes, prune back the plants in spring. This helps to reduce foliage size and promote strong growth for the next year’s bloom in the late summer/early fall.
Pruning back also promotes strong and vital root systems that store for the next season’s blooms. Cut back stems to at least one or two buds in spring after danger of frost has passed.
Soil
Do not prefer the soil that is too wet and too hot. You need to choose an ordinary commercial potting mix with an amount of 1/8 to 1/4 perlite mixture so that it makes sure that the soil will retain some moisture but will not get soggy.
Manage adequate drainage holes at the bottom of the pot to drain water. Remember not to leave the pot sitting in a saucer of water.
Temperature
The required temperature to grow this plant is 18 degrees Celsius to 25 degrees Celsius (64.4 F to 77.7 F), but during winter, this can be taken down to 10 degrees C (50 degrees F) or less.
Light
Avoid direct sunlight; however, early morning or late afternoon sun more suits the plant. It grows even in dimmer light but gives the best result in medium bright light (indirect light).
Pests and diseases
Sometimes aphids, a mealybug may harm Streptocarpus, but these plants are generally pest, disease-free and so commercial insecticides and cultural pest removal methods can treat quickly.
How do you get streptocarpus to flower?
Some varieties will bloom on and off all season, while others will bloom only when they receive adequate winter and spring rains. Overwatering during the growing season may cause streptocarpus to flower earlier than normal
What is the best way to propagate streptocarpus?
Most of these plants are so slow-growing they rarely need to be propagated except for those with unusual characteristics or those grown from seed.
Propagating streptocarpus by division is not feasible, as the tiny roots of each plant are too short to establish new plants from a piece of rootstock. To successfully bud new plants from older stems, graft or layering techniques are required.
What are the native soils that will work for streptocarpus?
Native soil for streptocarpus is a very common garden soil type used in many regions of the country. The best quality, loam-based soils will work the best.
Significant organic matter (i.e., compost and manure) should be incorporated into the seedbed before planting out the plants in spring or fall. Plant them about 2 ½ feet apart.
Mulch-ing during winter and early spring after the plants have germinated will help to conserve moisture and improve soil aeration to prevent weeds and competition with the plant for nutrients, water, and sunlight.
Where to buy the Streptocarpus plants and seeds?
You can find Streptocarpus for sale on Amazon. You can also buy streptocarpus plants in nurseries near you. Asking your local florists about buying Cape primrose may be helpful too.