Primula


The Primula species fits basically into three categories, namely alpine, border, and indoor.

The most common of these species are: allioni, alpicola, auricula, beesiana proliferae, candelabra, denticula, florindae, malacoides, obconica, pulverulenta, ripicola and vulgaris.

alpicola: (alpine)

A hardy herbaceous Primula which produces long scalloped mid green leaves with prominent veins and midrib.

The numerous scented funnel shaped flowers are borne on rigid stems that rise from the centre of each leaf cluster

alpicola

auricula: (outdoor / indoor)

This species forms clusters of 20mm (3/4") diameter flowers in umbels from March to may and grows to around 150mm (6") high with a similar spread.

auricula

beesiana: (outdoor)

This deciduous perennial is a good subject for a damp, woodland garden, as it enjoys moist, acidic to neutral soil in either sun or partial shade

The 50–60 cm high flower reddish-pink to purple flowers appear in late spring or early summer.

beesiana

candelabra:(outdoor)

This fully hardy primula is suited to a woodland garden and is particularly striking when planted in drifts.

The deep reddish-purple flowers grow in tiers on upright stems, and apear in late spring and early summer.

candelabra

denticulata:(border)

The Drumstick primrose is a vigorous perennial that is suited to growing in the border, rockery or as a pond marginal plant.

It grows approximately 300mm (12") high and should be planted out at 250mm centres.

It bears numerous 50-75mm globular flowers from March to May.

denticulata

florindae: (border)

One of the tallest and most fragrant of all the primula species, sometimes known as giant cowslip, is well suited for growing along the edges of ponds and streams.

The honey scented yellow flowers which can grow up to 75cm (30in) tall are held in loose clusters of pendulous blooms from late June to early September.

florindae

polyanthus: (border / indoor)

This is a hybrid originating from vulgaris and can be used as a border or pot plant.

It is a compact plant that grows approximately 200mm (8") high, and should be planted out at 250mm (10")centres, the clusters of 25mm diameter flowers are produced in March to April.

polyanthus

malacoides: (indoor)

The fairy primrose is a perennial generally grown as an annual.

The whorls of 12mm (1/2") diameter star like flowers are produced from December to April on slender 400-500mm(16"-18") stems.

malacoides

obconica:(indoor)

Obconica is another perennial that is generally grown as an annual.

It grows to around 400mm (16") high and the stems carry clusters of 25mm diameter flowers from December to May.

Some people get a painful allergic action from touching the leaves so it is recommended that gloves be worn when handling this plant.

obconica

pulvetrulenta:(border)

Is of the Candelabra group and can grow to a height of 900mm (36")

The flowers appear during June-July.

pulvetrulenta

vialii: (outdoor)

This is a rather distinctive two toned member of the primula family with its crimson-budded 30cm (12") tall spikes that open to expose lilac lanceolate flowers.

Ii is ideally suited for damp, shady spots, particularly if it is planted out in drifts along a stream or in a woodland setting.

vialii

vulgaris:(border)

This quite common species forms 50mm (2") high hummocks and spreads to around 150mm (6") diameter.

The 25mm wide flowers, one or two to a stem appear in March/April.

Winter dampness may damage the leaves, so it is better to grow this species in an alpine house.

vulgaris

Cultivation


Indoor species:


Plants should be grown initially, in 75-100mm pots then into 125mm pots of J.Innes No2 (or equivalent) in October.

As the flower stems start to lengthen, give regular weekly high potash liquid feeds.

Keep the plants moist at all times, and at a minimum temperature of 10°C (50°F)

Potted Polyanthus

Outdoor species:


This specie requires a fertile soil that is not subject to drying out in summer, therefore copious amounts of well rotted manure should be added prior to planting out.

A dressing of bonemeal spread at a rate of 4oz/sq metre should also be added at this time.

Polyanthus in border

Propagation:


Week 8:


Sow commercially purchased seeds on the surface of seed compost, then cover the containers with sheets of glass or polythene to preserve humidity and germinate at a temperature of about 16°- 18°C (60 °- 64 °F).

Temperatures must not exceed 18°C (64°F)


After germination cover the chitted seed with a fine layer of vermiculite and keep the compost moist and the seedlings lightly shaded.

Prick off the seedlings, when they are large enough to handle, into 75mm (3") pot of potting compost, and grow on in a coldframe until planting out time.


Week 24:


All primula seeds germinate best when they are fresh, so collect seed from established plants as soon as they are ripe.

Sow collected seeds on the surface of seed compost, then cover the containers with sheets of glass or polythene to preserve humidity and place in a coldframe to germinate.

Named varieties will not come true.

Germination will take about three weeks.


After germination keep the compost moist and the seedlings lightly shaded.

Prick off the seedlings, when they are large enough to handle, into 75mm (3") pot of potting compost, and grow on in a coldframe until planting out time.


Week 26:


Divide established plants after flowering and plant directly into their flowering positions.


Week 35:


Pot up plants to flower indoors in winter and early spring, and place in a coldframe until it is time to fetch them indoors.

Grow pot plants in 150mm (6") pots of potting compost.

Begin regular weekly liquid feeds when the buds appear.


Week 36:


Prepare bed by breaking up the soil thoroughly before planting, and digging in well rotted manure and finally raking in a balanced fertiliser at a rate of 100gms(4oz) per sq metre.


Week 38:


Plant between now and March, in sun or partial shade.

Border varieties require fertile garden soil that does not dry out in spring and summer.

Keep the soil moist in dry weather, by overhead spraying.

Mulching with peat preserves moisture.


Week 45:


For early flowering fetch pot plants indoors, site them where they can get maximum light, but not direct sunlight, and maintain a temperature of 10—13°C (50-55°F)

Plants can be divided after flowering, and planted directly into their new flowering positions.

Basal cuttings can be taken from auricula by taking 40-50mm shoots in June-August and inserting in 50-50 mixture of multipurpose compost and sharp sand then placing them in a cold frame.

When rooted pot up into 90mm diameter pots of Ji No1 potting compost and grow on in the cold frame till planting out time the following spring.


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