They naturally grow on the forest floor, usually at higher altitudes and often on mossy rocks. They require high humidity and are slow growing.
How to Grow Petrocosmea
Temperature and light are two important care factors.
Best at cooler temperatures 10C (77F) down to 5C (41F) at night.
Good filtered light is essential, this is a plant that grows naturally in shaded areas.
- Potting Mix/Soil
A light free draining mix that holds some moisture.
Best by sitting the pot in of water for 15 minutes and then allowing to drain. Use room temperature water and preferably water that has been allowed to stand for a day to help chlorine and other chemical to dissipate.
Sit the pot on rock in a saucer of water, the pot should be above the water. Do not mist spray as this can cause fungal problems
Use a liquid African Violet fertilizer dilutes by 50% from spring through summer.
How to Propagate Petrocosmea
You can propagate Petrocosmea from leaf cuttings and from seed. You can also wait for the plant to put out offsets and then remove them, this is even easier. Leaf cuttings is the preferred method, this is how we go about it.
- Use a simple African Violet potting mix with around 30% Perlite/Vermiculite mix for strong results. You can also use a 50/50 Perlite/Vermiculite mix.
- Use small pots set into another tray for ease of handling. Square pots are best. You can use single pots to start out with.
- Take whole leaf cuttings making sure you get all of the leaf where it attaches to the stem.
- Set the leaves on top of the mix and cover with a cloche or propagation tray cover to maintain humidity.
- Some growers cut away the lower section of the leaf on each side of the central rib to create a ’stem’.
- Place in good filtered light or under grow lights.
- Keep just moist.
- Leaf cuttings can take 3 – 4 weeks to show signs of growth.
- Once new growth appears begin fertilising,
- Once the cutting forms a rosettes, pot up into your normal soil mix.
How long does it take Petrocosmea to Grow ?
This depends on the species, some are slower growing than other. As a guide, from leaf cutting to a small plant will take around 9 – 12 months.
These plants are part of the Gesneriaceae family of plants that also includes :
- African Violets