SUCCESS WITH STREPTOCARPUS
CARE OF PLANTS
Coming mainly from South Africa and growing in wooded damp and shaded areas, they get plenty of light but very little direct sunlight. They do not like full sun. If your plants are in the house, the best place to keep them is on an east to west windowsill - if this cannot be done, shade during full sun.
In a greenhouse or conservatory you will need to shade most of the time during summer, just enough to keep the full sun from scorching the plants.
Summer watering can be twice a day on very hot days but if in doubt feel the pot weight - this will tell you if the plant requires a drink or not. Sometimes during summer you may find the plant and the flowers wilting. If this happens do not water until the temperature has cooled and you will probably find by mid evening that they are all standing up as if nothing had happened to them. They may need a drink or they may not. If plants do suffer heat damage/severe wilting (as in photos below), remember to given them a full strength feed at the next watering.
Right are Vine Weevil grubs which may be found in pots eating the roots of plants.
Winter watering (from November until the end of February): they only need to be kept JUST MOIST - this will vary from house to greenhouse (much less in the greenhouse).
OVERWATERING BOTH IN SUMMER AND WINTER WILL CAUSE ROOT ROT AND THE PLANT MAY DIE.
Use any good houseplant fertilizer high in potash (Phostrogen or Tomato fertilizer) at ¼ strength of the manufacturer's directions each time you water. It is better to under-fertilize as too much may damage the root system and cause browning of the leaves. High potash feed will increase your flower quantity and quality.
PLANT CARE AND CLEAN UP
During flowering take off all dead flowers at least once a week. When the flower stem has finished flowering cut it from the plant as low as you can to the leaf base. Any leaves that get tatty or too large you can trim with scissors to the shape you require.
In winter, when the plant is almost dormant, take the old leaves off that have flowered that year as close to the base of the plant as you can - the stump will pull off about a month later. This will leave room for the new leaves to form for next year's flowers.
PESTS AND DISEASES
Streptocarpus are not subject to many pests or diseases and reasonable precautions can prevent most of these. To prevent the leaves from getting brown on the edges, keep them away from bright sunlight and do not water over the top of the plant.
Prevention is always better than any cure and one approach is to make use of Provado Ultimate Bug Killer before any pests are seen. You can water your plants with this and it should keep Greenfly, Blackfly, Sciarid Fly and the Vine Weevil at bay for up to six months. As streps do not need a lot of water in one go we recommend that you use Provado for two waterings - this will give the plant the quantity it requires and you will not over water the plants.
You can also use Provado Ultimate Bug Killer (Concentrate or Aerosol) to get rid of most Aphids, Red Spider Mite, Thrips and Mealybug. If you do use a spray try to keep it off the flowers. If you only have a few greenfly on the flower stalks, use the finger and thumb method. Hold the plant at an angle over a sheet of newspaper and just rub the flower stem - the ones that drop you can kill after. Another cure for Mealybug is methylated spirits; just dab it on with a cotton wool bud which is a bit time consuming but can be successful in eliminating the pest.
Powdery mildew can be treated with Provado Fungus Fighter - use as for ornamentals
A very rare and definitely unwanted pest is Root Mealybug. It is very difficult to spot and will probably require magnification to see. The bugs move very slowly and look a bit like ant eggs. They can often be confused with vermiculite if that has been added to the compost. Root Mealybug eat away the roots and eventually cause palnt collapse. They also spread to other plants in the vicinity. There is little that can be done about this pest and the general opionion is that the plants should be destroyed along with the pots they are growing in. Provado Vine Weevil Killer can be used with cuttings but has little effect on larger plants.
If you are growing in the house or greenhouse and do not want to use any of the above you can use Biological Control - ring SCARLETTS on 01206 242533 or email firstname.lastname@example.org
Their website is at www.scarletts.co.uk
Print off an information sheet about propagation from leaf cuttings written by Frank Davies.
Print off an information sheet about propagation from seeds written by Frank Davies.
Lots more helpful information and 5 useful factsheets about streptocarpus to print off at:
Useful information and details about care and propagation of Streptocarpus at the links below:
Left are Root Mealybugs which may be found in pots eating the roots of plants but are more difficult to sport than Vine Weevil grubs and are not always as clearly seen as in this photo.