Streptocarpus?

By Dave G. (Strepbystrep) on April 25, 2014

What is a Streptocarpus? Those who grow these wonderful houseplants refer to them as Streps. Why such a weird name for a plant that is often confused with a bacteria (Streptococcus) which causes strep throat? Well, the answer is rather simple, it is derived from the Greek words streptos which means twisted and carpus which means fruit. When the flower is pollinated, the seed pod becomes twisted as the pod develops.


What is a Streptocarpus? Those who grow these wonderful houseplants refer to them as Streps. Why such a weird name for a plant that is often confused with a bacteria (Streptococcus) which causes strep throat? Well, the answer is rather simple, it is derived from the Greek words streptos which means twisted and carpus which means fruit. When the flower is pollinated, the seed pod becomes twisted as the pod develops.

These plants are also known by their more common name, Cape Primrose. Although, recently another name has emerged, Lady Slippers with the variety's name immediately following. Fortunately, only one commercial grower is using this name that I am aware of. 

Confused yet? So much confusion for a simply elegant flowering plant! Like it's cousin the African Violet, this plant will reward you with many beautiful blooms. Both the African Violet and Streptocarpus belong to the Gesneriad family.

Like their cousin, Streptocarpus blooms come in red, white, purple, pink, lavender, blue-purple, yellow, coral, fuchsia, bi-colors and fantasy. The plants are available as standard, compact and miniature. There are also varieties with variegated foliage.

Culture is basically the same, bright indirect light, temps 65-75 degrees is ideal, plants will tolerate temps as low as 60 degrees. However, their growth will start to slow as well as their bloom. On the high side, temps to 80 degrees will not hinder the plant. Temps higher than 80 degrees will need to be monitored as too high of a temperature for long periods of time will tend to deplete the plant and ultimately lead to it's demise.

This is a general rule to go by. Like everything in life there are exceptions. I have grown streps successfully in a greenhouse where summer temps were 95-105 degrees. With good air circulation and higher humidity it is possible to grow streps in these temps. In this case, the humidity level was 75-80%.

To grow any plant successfully, this is a cold hard fact. Night temps must be 10 degrees cooler than daytime temps! The temperature difference may be slightly greater however, be careful not to have wild temperature extremes as this will promote powdery mildew and other possible fungal problems for plants.

Streps like to dry between waterings. The best advice I can give is if in doubt, stick your finger down into the soil about 1." If it feels damp do not water, if it feels dry water thoroughly. If the plant dries too much it will droop, however, they are tough and will revive after a drink. Try not to let this happen as the leaf tips will die back if it happens too often.

Streps will tolerate an occasional overwatering but if done too often the plant will collapse. Often it is crown rot and when this happens the plant separates from it's roots when you lift the plant slightly.

The two major challenges for anyone beginning to grow streps are;

1. Soil. Streps like their cousin the African Violet like a light porous soil. However, the pre-packaged AV soil and the standard 1:1:1 mix most growers use is a little heavy for streps in my opinion. For Streps add about 20% more perlite to your mix. This is just a guide as in the Southern part of the country where it is generally hotter, you may not want your plants to dry to quickly.

A trick I encourage beginners to do is drill or melt 4 holes equally spaced along the bottom sides of the pot. You may say, oh, that takes away from the looks of the pot. If you are melting the holes, wait until the plastic cools and scrape the burrs gently with a knife. It will look as though the pot was manufactured this way.

So why the holes? Many beginners make the mistake of overwatering streps. Even the experienced AV grower is usually guilty of this. Unlike the AV which, may tolerate wet roots over a period of time, it will be a sure death for streps. The holes allow air to the roots, thus less chance the roots will be too wet.

2. Watering. Water your plants thoroughly. When top watering, make sure water runs from the drainage holes. This is very important for two reasons. One, it encourages deep root development. Two, by watering thoroughly, it helps flush out fertilizer salts which build up in the soil over time.

Streps like to dry between waterings. The best advice I can give is if in doubt, stick your finger down into the soil about 1." If it feels damp do not water, if it feels dry water thoroughly. If the plant dries too much it will droop, however, they are tough and will revive after a drink. Try not to let this happen as the leaf tips will die back if it happens too often.

Streps will tolerate an occasional overwatering but if too often the plant will droop, looking like it needs water. Often it is crown rot and when this happens the plant separates from it's roots when you lift the plant slightly

Now let's talk about light. Streps will grow in the same light conditions as African Violets do. They will tolerate and even enjoy a slightly higher light level than an AV. The same rule applies to streps, keep out of direct light! Though they are tough, they will burn! A sign the plant is getting too much light is leaves have a bleached look or are turning yellow. A healthy strep leaf should be a nice healthy green. If the light is not sufficient, bloom will be sparse and leaves a darker green.

Some strep varieties do have a dark green leaf which may have a red pigmentation on the underside of the leaf. This is normal and not a sign of insufficient light.

Feeding your strep is a little different than feeding an African Violet. With African Violets to encourage bloom many growers use a blossom booster type fertilizer (12-36-14) is a popular formula. While this will work wonderfully for their cousins, for Streps it is a death sentence! A high phosphorous level is deadly over a short period of time.

Phosphorous is the middle number in the fertilizer formula. Use a fertilizer which is balanced at the very minimum. (7-7-7, 20-20-20,etc.) Preferably, urea free and a formula with a lower phosphorous number. Personally, I use Better-Gro orchid fertilizer 20-13-14 with great results. The key is phosphorus IS NOT the highest number in any fertilizer used.

Streps are like to be fed constantly but weakly. Rule of thumb, 1/4 strength of manufacturer's recommendation works well. Whether you top water or wick, I encourage you to once a month water with plain water to flush out any salts which can build up over time. Make sure the water runs out of your drainage holes!

Last but not least, repotting. Like their cousin, they bloom best when their roots are confined. Use as small a pot as possible when repotting your plants. Too large a pot will create problems and will most likely cause your plant an untimely death.

Streps love to be repotted! These plants tend to grow very quickly once they become established. You will find a happy strep will usually require repotting about every 6 months. I would encourage you never to leave a strep in the same soil for longer than 1 year.

These are the basics to have a happy, healthy, thriving Strep! There are many more tips, words of advice, and more in depth topics and explanations that need to be covered another day. My hope this will be helpful in your endeavors.

One last thing, did I mention Streptocarpus bloom and bloom and bloom? Much more freely than most AV's (yes, I started another debate) and much faster from baby to first bloom? On average, the first bloom on a Strep is 4-6 months. Good luck with growing your Streps!

Email any questions to: [email protected]

Or join us @ cubits.org/Strepbystrep
There, you may ask any questions on our forum.

Related articles:

« More articles

Comments and discussion:
Subject Thread Starter Last Reply Replies
Untitled JoAnnWVa Jun 12, 2014 9:30 PM 1

StrepbyStrep

Welcome to Strep by Strep! Whether your a novice, an experienced grower, or anywhere in between, this is your haven to discuss, share successes, failures, tips, buy, sell or trade your favorite Gesneriad.

» Home
» Forums
» Articles
» Pages
» Links

Cubit owner: Strepbystrep

Admin team:

» Contact the admins