The Gardeners Almanac

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Week Numbers

Compost

Deadheading

Fertiliser

Heating

House plants

Leaf cuttings

Pricking out

Seed sowing

Ventilation

Watering

Overview:

Streptocarpus is a tender greenhouse perennial originating from Africa.

They grow to around 300mm (12") high, with a similar spread, and flower from late May until October.

Some hybrid varieties can flower all the year round given the right growing conditions.

Maintain a minimum winter temperature of 8°-10°C (45°-50°F), rising to 15°-21°C (60°-70°F) during the growing season.

Water regularly during the growing period and keep the plants just moist between November and March.

They prefer dappled shade, cool temperatures, and good humidity from April to September.

Direct sunlight can cause burning to the leaves and the flowers.

Even so, it is important that they get adequate light as too little light can lead to plants producing leaves at the expense of flowers.

If grown in the greenhouse give good ventilation during the hotter months of summer.

They they halve a shallow root system and these should be kept cool so shading the pots can be beneficial.

Keep the plants on the root bound or pot bound side, to encourage flowering.

Watering:

Water regularly but take care not to overwater!

Wet compost can lead to root rot.

Allow pots to go quite dry between waterings.

Test for dryness by scraping back the top 12mm (½") of compost and inspecting the compost below.

Another method is to feel the weight of the pots and if they feel much lighter water them.

Wilting leaves can also be an indication but is not to be relied on as there can be other cause of leaf droop.

Cultivation:

Week 4-10:

Sow seeds in pots/ trays of seed compost, and germinate at a temperature of 20°C (68°F).

Germination should take around two weeks.

Method:

Fill clean tray with a proprietory seed compost.

Soak the seed compost prior to sowing and this will avoid the possibility of washing the seed to one area of the tray.

Streptocarpus seeds are very fine, adding a drop of silver sand to the seed packet prior to sowing will make the task of sowing much easier.

Once the seed are sown cover them with a propagator lid or piece of glass and place them in a propagator or on a hotbed set to give a temperature of 20°C (68°F).

Daily wipe off any condensation that may have formed on the lid / glass.

Week 17:

When the seedlings are large enough to handle, prick them out into plug trays and later singly into 75mm (3") pots of well drained potting compost,then pot on as necessary.

Streptocarpus have a shallow root systems, so when potting on, grow them in shallow wide pots/pans.

Repotting into fresh compost should be done annually.

Week 20:

Take leaf cuttings by inserting approximately 50mm (2") cross sections of leaves, or two longitudinal sections of the whole leaves into a rooting medium* and root at a temperature of 18°C(65°F).

Example Rooting Mediums:

• 100% Seed Compost


• 50% (by volume) Sifted Peat mixed with 50% Silver Sand.


• 100% Vermiculite


• 50% Seed Compost (by volume) mixed with 50% Vermiculite.


• 100% Perlite.

Ensure that the cuttings are inserted the correct way up, i.e. insert bottom of cut into compost.

Method:

Small Cross section Cuttings:

 

Longitudinal Cuttings:

 

When small plantlets have developed from any of the cutting methods described above, pot them singly into 75m (3") pots of potting compost.

Pot on as necessary (see note above)

Week 25:

• Apply a weak high potash liquid feed at 10-14 day intervals from now until they stop flowering.


• Place plants outdoors in a shaded position and protect them from slug and snail attack, return them indoors in before the first frosts.


• If growing on indoors, position plants in good light but do not expose them to hot sunlight, to do so cause leaf scorch.


• Position them in an east or west-facing windowsill in summer and south-facing in winter.


• Increase humidity by standing the pots on saucers of pebbles kept moist, but do not allow the water to reach the base of the pot.

General Information :

Over-watering can cause leaves to rot at their base.

Over-large leaves might be due to poor light and/or excessive feeding.

Leaf die back late on in the year is a natural condition, and is due to shorter day length, cooler temperatures and reduced moisture uptake, if this occurs trim the dead leaf tissue off.

Deadhead once blooms have faded to promote more.

Do not allow any dead flowers to fall onto the foliage this could cause grey mould or botrytis.

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