Nick,
The subject of growing successful pot or even mammoth blanch leeks is a highly secret and covert process. Sums of money will often be charged by seed catalogues to learn the myths and practices of said subject. Please do not reveal the following in case my membership to the magic pot leek circle is cancelled!
I apologise in advance as this will be a mammoth ( ) article in itself and some bits will slip into technical land but am sure you will keep up. You do not have to follow this as gospel to achieve good results….just use it as a guide to the time you have available.
Firstly I do not grow my pot leeks for show, primarily it’s for pride….if I think they are good enough I may enter them at a show but that is secondary.
Just to clear up some terms, there are three kinds of leek in this field; Pot leeks having a blanched area no longer than 15cm (6in) – with the largest possible circumference, Blanch leeks which comprise Intermediate leeks having a blanched length of between 15 and 35cm (6 – 14in) and Long leeks having a blanched length from 23cm (9in) upwards, sometimes exceeding 60cm (24in).
All leeks can be raised vegetatively by propagating pods (sometimes known as bulbils or pips). Alternatively, they can be grown from plants or seeds. These items are not always easy to obtain, if exhibition quality results are required. They may be purchased from nurseries and there are specialist growers who advertise in the gardening journals, yellow free ad paper etc. Best plants start by using best seed…..you may not want to exhibit your results but you may want the results to be of exhibition quality. In the North East it is common to see plants offered in Feb for about Ł1 each.
Starting from pods:
I will start here because this is my method.
The advantage of raising from pods is that the offspring will have the same characteristics as the parent and, if this were a prize-winner, the pods would be potential prize-winners also. Pods are the delicate swellings which form on the head of the plant after flowering. Pot leek pods resemble very small dried tulip bulbs, but some varieties produce pods, each with a single live leaf, which looks like a blade of grass. These are known as ‘grass’ leeks.
The pods of Blanch leeks resemble miniature plants. Separate the pods from the head, being careful not to damage them, and examine each one for signs of disease. Any that show a reddish/brown mark at the base must be discarded. They may grow and appear healthy but when the leeks start to mature the flags (leaves) begin to decay and sometimes the whole plant collapses.
Start Blanch leeks off in December and Pot leeks in January in a temperature of about 12-15°C (55-60°F) in a greenhouse, on a warm windowsill or in a heated propagator.
A proprietary, peat-based compost or loam based John Innes No. 1 may be used. Plant individually into 7cm (3in) pots. Blanch leek pods should be planted leaving half their length above the surface, but Pot leek pods should be pushed gently into the surface of the damp compost and not buried, whilst ‘grass’ leeks should be planted about 6mm (1/4 in) deep. Blanch and ‘grass’ leeks will benefit from a twice weekly foliar feed with half strength plant foodsolution, i.e. half a level teaspoonful in 9 litres (2 gals) of water, as this will help to keep them fresh and encourage root development.
Always avoid foliar feeding in direct sunlight as a liquid of any kind on the foliage can cause scorch. Keep the compost moist with water at all times.
Starting from seed:
Sow in January using the same compost recommended above. Use a large tray so that the seeds can be well spaced. Avoid over watering. It is worthwhile using a seed dressing, if available, to ensure good germination. Keep at a temperature of about 12-
15°C (55-60°F) in a greenhouse, on a warn windowsill or in a heated propagator, until the seedlings are large enough to handle, then transfer then singularly into 7cm (3in) pots treating them as for Pods.
As a comparison my strain of pot leek will stand for 13 months without bolting to seed, so they get planted in the Autumn…..you wont find that recommended in a seed catalogue!
Greenhouse culture:
Keep the temperature at about 12°C (55-60°F). After about three weeks, examine the root formations and those that show abundance should be moved into 15cm (6in) pots. If John Innes compost is used, then this should be No.3. Feeding is very important from about two to three weeks after potting. Root feed with full strength plant food i.e. a level teaspoonful in 9 litres (2 gals) of water every ten days and foliar feed with half strength solution at least one a week.
Many Pot leeks need to be ‘drawn’ to their required length of blanch and ‘collars’ are slipped over the plants from February onwards to force their growth upwards. The collars, plastic or cardboard tubes about 10cm (4in) long, should not be tight but should exclude as much light as possible. Some varieties need little encouragement to grow to the required length and ‘earthing up’ when they are transferred into the garden will blanch them sufficiently. When buying Pot leek plants, always ask if they need ‘drawing’ or not. By the end of March, the plants are transferred into 22cm (9in) pots.
Pot leeks remain in the warmth of the greenhouse, whilst Blanch leeks are transferred to cold frames to be planted out in April.
Soil preparation:
Blanch leeks are planted out in open ground in mid to late April. Pot leeks are removed from the greenhouse to the open ground at the end of May in the South, the first week in June for me. From now on they are at the mercy of the weather until Show time, usually September. The soil should be well prepared. If it is well drained, friable and not too stony it may only be necessary to add well-rotted farmyard manure, garden compost or, failing that, spent mushroom compost. A full barrow load per square metre (about 1 sq yd) is essential for exhibition plants. Where the soil is poor because of clay, stones or poor drainage, a prepared bed, called a ‘trench’ is required.
Preparation of a trench:
A trench 5 metres x 1 metre (about 16ft x 4ft) will accommodate 22 leeks. It should be mounded up to 45cm (18 in) above the normal soil level. The sides will need supporting with corrugated steel, breezeblocks or bricks. Timber is not recommended as it harbours pests and diseases. The trench should be prepared to an overall depth of
1 metre (about 3ft) as follows: The bottom 15cm (6in) should be weathered ashes, or a similar aggregate, covered with a 15cm (6in) layer of straw, from broken up bales, to prevent the ashes becoming clogged with soil making drainage ineffective. A 45cm
(18in) layer of farmyard manure or garden compost is then added and the trench brought to its full height with good, friable soil. Each year, more manure or compost is added, but the bottom of the trench is never disturbed. Good initial preparation is, therefore essential.
Planting outdoors:
Pot leeks should have 7 to 10 days hardening off in a cold frame before planting out. About a week before planting, rake 50g plant food powder per sq metre (per 1 sq yd) into the surface of the soil. Pot leeks are planted with soil up to their lowest flag whilst Blanch leeks are planted so that their bases are about 10cm (4in) below the surface. Make a suitable hole for each plant and sprinkle in a little plant foodpowder to encourage the roots to penetrate the soil. From now on the soil is never allowed to dry out. Root and foliar feed once a week with full strength plant foodfrom the end of June onwards. Regular feeds are essential for actively growing leeks; the high potash content of plant foodkeeps the plants robust.
Lengthening blanch leeks:
When the plants show about 20cm (8in) above the surface, place a cardboard tube about 10cm (about 4in) long and 25mm (1in) in diameter over each one. This is replaced with a standard land drain tile 30cm x 9cm (12in x 31/2in) when the plants reach 45cm (about 18 in) in length. By improvising with tubes of various sizes, the length of the leek can be slowly increased. Never cover the uppermost third of the plant; this only weakens the growth.
If when September comes you want to show your leeks to the world, or the village show at least here is my only tip - Lift the selected leeks the evening before the Show and wash them down with a hosepipe from the roots to the flags. Stand the plants in a bucket containing sufficient full strength plant foodsolution to cover the roots and you will find they are a little larger the following day!
BE WARNED: This type of vegetable growing can take over your life….you may not be the same person again!!
I think I deserve a nice cold beer now.
The subject of growing successful pot or even mammoth blanch leeks is a highly secret and covert process. Sums of money will often be charged by seed catalogues to learn the myths and practices of said subject. Please do not reveal the following in case my membership to the magic pot leek circle is cancelled!
I apologise in advance as this will be a mammoth ( ) article in itself and some bits will slip into technical land but am sure you will keep up. You do not have to follow this as gospel to achieve good results….just use it as a guide to the time you have available.
Firstly I do not grow my pot leeks for show, primarily it’s for pride….if I think they are good enough I may enter them at a show but that is secondary.
Just to clear up some terms, there are three kinds of leek in this field; Pot leeks having a blanched area no longer than 15cm (6in) – with the largest possible circumference, Blanch leeks which comprise Intermediate leeks having a blanched length of between 15 and 35cm (6 – 14in) and Long leeks having a blanched length from 23cm (9in) upwards, sometimes exceeding 60cm (24in).
All leeks can be raised vegetatively by propagating pods (sometimes known as bulbils or pips). Alternatively, they can be grown from plants or seeds. These items are not always easy to obtain, if exhibition quality results are required. They may be purchased from nurseries and there are specialist growers who advertise in the gardening journals, yellow free ad paper etc. Best plants start by using best seed…..you may not want to exhibit your results but you may want the results to be of exhibition quality. In the North East it is common to see plants offered in Feb for about Ł1 each.
Starting from pods:
I will start here because this is my method.
The advantage of raising from pods is that the offspring will have the same characteristics as the parent and, if this were a prize-winner, the pods would be potential prize-winners also. Pods are the delicate swellings which form on the head of the plant after flowering. Pot leek pods resemble very small dried tulip bulbs, but some varieties produce pods, each with a single live leaf, which looks like a blade of grass. These are known as ‘grass’ leeks.
The pods of Blanch leeks resemble miniature plants. Separate the pods from the head, being careful not to damage them, and examine each one for signs of disease. Any that show a reddish/brown mark at the base must be discarded. They may grow and appear healthy but when the leeks start to mature the flags (leaves) begin to decay and sometimes the whole plant collapses.
Start Blanch leeks off in December and Pot leeks in January in a temperature of about 12-15°C (55-60°F) in a greenhouse, on a warm windowsill or in a heated propagator.
A proprietary, peat-based compost or loam based John Innes No. 1 may be used. Plant individually into 7cm (3in) pots. Blanch leek pods should be planted leaving half their length above the surface, but Pot leek pods should be pushed gently into the surface of the damp compost and not buried, whilst ‘grass’ leeks should be planted about 6mm (1/4 in) deep. Blanch and ‘grass’ leeks will benefit from a twice weekly foliar feed with half strength plant foodsolution, i.e. half a level teaspoonful in 9 litres (2 gals) of water, as this will help to keep them fresh and encourage root development.
Always avoid foliar feeding in direct sunlight as a liquid of any kind on the foliage can cause scorch. Keep the compost moist with water at all times.
Starting from seed:
Sow in January using the same compost recommended above. Use a large tray so that the seeds can be well spaced. Avoid over watering. It is worthwhile using a seed dressing, if available, to ensure good germination. Keep at a temperature of about 12-
15°C (55-60°F) in a greenhouse, on a warn windowsill or in a heated propagator, until the seedlings are large enough to handle, then transfer then singularly into 7cm (3in) pots treating them as for Pods.
As a comparison my strain of pot leek will stand for 13 months without bolting to seed, so they get planted in the Autumn…..you wont find that recommended in a seed catalogue!
Greenhouse culture:
Keep the temperature at about 12°C (55-60°F). After about three weeks, examine the root formations and those that show abundance should be moved into 15cm (6in) pots. If John Innes compost is used, then this should be No.3. Feeding is very important from about two to three weeks after potting. Root feed with full strength plant food i.e. a level teaspoonful in 9 litres (2 gals) of water every ten days and foliar feed with half strength solution at least one a week.
Many Pot leeks need to be ‘drawn’ to their required length of blanch and ‘collars’ are slipped over the plants from February onwards to force their growth upwards. The collars, plastic or cardboard tubes about 10cm (4in) long, should not be tight but should exclude as much light as possible. Some varieties need little encouragement to grow to the required length and ‘earthing up’ when they are transferred into the garden will blanch them sufficiently. When buying Pot leek plants, always ask if they need ‘drawing’ or not. By the end of March, the plants are transferred into 22cm (9in) pots.
Pot leeks remain in the warmth of the greenhouse, whilst Blanch leeks are transferred to cold frames to be planted out in April.
Soil preparation:
Blanch leeks are planted out in open ground in mid to late April. Pot leeks are removed from the greenhouse to the open ground at the end of May in the South, the first week in June for me. From now on they are at the mercy of the weather until Show time, usually September. The soil should be well prepared. If it is well drained, friable and not too stony it may only be necessary to add well-rotted farmyard manure, garden compost or, failing that, spent mushroom compost. A full barrow load per square metre (about 1 sq yd) is essential for exhibition plants. Where the soil is poor because of clay, stones or poor drainage, a prepared bed, called a ‘trench’ is required.
Preparation of a trench:
A trench 5 metres x 1 metre (about 16ft x 4ft) will accommodate 22 leeks. It should be mounded up to 45cm (18 in) above the normal soil level. The sides will need supporting with corrugated steel, breezeblocks or bricks. Timber is not recommended as it harbours pests and diseases. The trench should be prepared to an overall depth of
1 metre (about 3ft) as follows: The bottom 15cm (6in) should be weathered ashes, or a similar aggregate, covered with a 15cm (6in) layer of straw, from broken up bales, to prevent the ashes becoming clogged with soil making drainage ineffective. A 45cm
(18in) layer of farmyard manure or garden compost is then added and the trench brought to its full height with good, friable soil. Each year, more manure or compost is added, but the bottom of the trench is never disturbed. Good initial preparation is, therefore essential.
Planting outdoors:
Pot leeks should have 7 to 10 days hardening off in a cold frame before planting out. About a week before planting, rake 50g plant food powder per sq metre (per 1 sq yd) into the surface of the soil. Pot leeks are planted with soil up to their lowest flag whilst Blanch leeks are planted so that their bases are about 10cm (4in) below the surface. Make a suitable hole for each plant and sprinkle in a little plant foodpowder to encourage the roots to penetrate the soil. From now on the soil is never allowed to dry out. Root and foliar feed once a week with full strength plant foodfrom the end of June onwards. Regular feeds are essential for actively growing leeks; the high potash content of plant foodkeeps the plants robust.
Lengthening blanch leeks:
When the plants show about 20cm (8in) above the surface, place a cardboard tube about 10cm (about 4in) long and 25mm (1in) in diameter over each one. This is replaced with a standard land drain tile 30cm x 9cm (12in x 31/2in) when the plants reach 45cm (about 18 in) in length. By improvising with tubes of various sizes, the length of the leek can be slowly increased. Never cover the uppermost third of the plant; this only weakens the growth.
If when September comes you want to show your leeks to the world, or the village show at least here is my only tip - Lift the selected leeks the evening before the Show and wash them down with a hosepipe from the roots to the flags. Stand the plants in a bucket containing sufficient full strength plant foodsolution to cover the roots and you will find they are a little larger the following day!
BE WARNED: This type of vegetable growing can take over your life….you may not be the same person again!!
I think I deserve a nice cold beer now.
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