The Gardeners Almanac

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Sinningia

Common name: Gloxinia

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Week Numbers

Basal cuttings

Compost

Deadheading

Division

Fertiliser

Heating

House plants

Leaf cuttings

Pricking out

Seed sowing

Watering

Overview:

Close up of double red flower edged in white

Flowerhead

 Plant with single red flowers tipped with white

Sinningia

Sinningia is a greenhouse pot plant that is also suited for growing indoors.

Plants need full sunlight to perform at their best, shade will result in poor flower quality.

Aim for a temperature of 16°-21°C (60°-70°F) during the growing season.

If temperatures are in excess of this increase ventilation to control it.


They grow to 250-300mm (10"-12") high with a similar spread, flowering from late May through to September.

Feed the plants with balanced liquid fertiliser, at seven to ten day intervals, from the time the flower buds are visible.

Keep the plants moist throughout their growing period.

Allow the plants to go slightly dry between waterings.

To avoid water sitting in the crown of the plant, allow the pots to sit in a bowl of water to soak for an hour to saturate the compost. Once they have been removed from the bowl any surplus moisture will drain off automatically.


Cultivation:

Week 6:

Place the dormant tubers in pots/trays of moist compost and start them into growth at a temperature of 21°C (70°F).

Ensure that top rim of the tuber is located at the surface of the compost and not buried!

They will cope with a light covering but not deep cover!


It is often difficult to tell which side is the top.

To determine this look for a small group of tiny points (growing buds), these can be on the top and or on the side of the tuber next to some roots.

These points determine what is the top of the tuber.

Failing that plant the tuber on its side, and allow nature to take its course, this will result in the top growth eventually growing towards the surface.


When the young growth is about 50mm (2") high, pot them up into 150mm (6") pots proprietary soiless compost, placing the top of the tubers level with the surface of the compost.

If they were initially grown on their side slightly bury the tuber!


Week 10:

Sow seeds on the surface of a proprietary seed compost and germinate at a temperature of 20°-24°C (68°-75°F).

Germination should take around three weeks.


When the second true leaves have developed,(approx 5 weeks) prick the seedlings into 75mm (3") pots of potting compost and grow on at a minimum temperature of 13°-21°C (55°-70°F).

Pot on as necessary, until reaching their final pot size.

Grow the young plants on in a shaded greenhouse with a humid atmosphere and at a temperature of around 16°-21°C (60°-70°F).

One year old plants will often produce flowers in late summer.


Week 14:

Divide tubers into pieces, each having one or two growing shoots.

Cauterise (seal) the cuts with flowers of sulphur or powdered charcoal.

Pot the pieces separately into 75mm (3") pots containing the growing mixture.

Gloxinias can also be increased by taking basal or leaf cuttings. (see below)


Week 18:

Take 50-70mm (2"-3") long basal shoots with a sliver of tuber, and insert them into compost consisting of equal parts (by volume) peat and sand, then place in a propagator at a temperature of 21°C (70°F).

Once the cuttings have rooted pot them up into 75mm (3") pots of potting compost and grow on.

They should reach flowering size in four to six months.


Week 26:

Take leaf cuttings by removing complete leaves.

Slit the veins on the underside of each leaf with a sharp knife, making the cut just below the junction of the main veins.

Place the leaves, cut side downwards, on the surface of a compost consisting of equal parts (by volume) peat and sand, then place in a propagator at a temperature of 21°C (70 F).

Roots will develop from the cuts and mature into small plants.


Week 44:

As foliage begins to yellow gradually reduce watering.


Winter storage:

As the leaves begin to turn yellow, gradually cease watering and feeding, and remove any dead flowers and leaves.

Leave the tuber in its pot and allow the compost to go quite dry.

Keep the tuber at 4°-10°C (40°-50°F) until new growth appears in spring then start it into full growing mode from then.

Discard tubers that are more than three years old.