Newcomers to vegetable growing soon learn that growing traditional celery involves a lot of effort. Trenches must be prepared and the stems must be earthed-up at intervals until only the green leafy tips are showing. This latter process of earthing-up is often called blanching, but that is something of a misnomer. The main purpose is not to whiten the stems – it is to lengthen and reduce the stringiness of the stalks and to improve the flavour. Nowadays we have self-blanching varieties and so both trenching and earthing-up are no longer necessary. These varieties are less crisp and less flavouring, and cannot be left in the ground once the frosts arrive, but they do make celery growing easier. Easier, but not easy. Humus-rich soil is still necessary and so are regular watering and feeding.

Seed facts
Expected germination time: 12-18 days
Approximate number per ounce: 70,000
Expected yield from a 10ft row: 12lb (6kg)
Life expectancy of stored seed: 5 years.
Approximate time between sowing and picking: (Trench varieties) 40 weeks; (Self-blanching varieties) 25 weeks.
Ease of cultivation: Difficult – especially the trench varieties.

Soil facts
· All varieties require a sunny site and well-prepared soil. For self-blanching types dig a bed in April – incorporate a generous dressing of manure or compost.
· For trench varieties prepare a ‘celery trench’ in April and allow to settle until planting time.
· Just before planting rake a general-purpose fertilizer into the surface inch of the bed or trench.

Sowing and Planting
· Sow seeds under glass and harden off the seedlings before planting outdoors. Seedlings are ready for transplanting when there are 5 or 6 leaves.
· Prepare a ‘celery trench’ – dig it 12in (30cm) deep and 15in (37cm) wide, and fork over the bottom. Then place in a layer of well-trodden manure or compost, and then a layer of soil to within 3in (7cm) of ground level. Plant seedlings 9in (23cm) apart in the trench.
· Self-blanching varieties are planted 9in (23cm) apart in a square block (not in rows) so that the crowded plants will shade each other. Trench varieties are set out at 9in (23cm) intervals – fill the trench with water after planting.

Calendar
· Buy celery seedlings for planting in late May-mid June. Or raise your own by sowing seed under heated glass between March and early April – make sure that the seedlings do not receive any check to growth and ensure that the plants are properly hardened off before planting.
· Self-blanching varieties will be ready for lifting between August and October. The trench varieties are grown for winter use from October until mid to late February.

Looking after the crop
· Celery is a thirsty and hungry crop – water copiously in dry weather and liquid feed with Instant Bio during the summer months.
· Blanch trench varieties in early August when they are about 1ft high. Remove any side shoots, surround the stalks with newspaper or corrugated cardboard and tie loosely, after which the trench should be filled in with soil. In late August mound moist soil against the stems and in mid September complete earthing-up to give a steep-sided mound with only the foliage tops showing. Do not let soil fall into the celery hearts. In frosty weather cover the tops with straw.
· With self-blanching celery tuck straw between the plants forming the outside line of the bed.

Harvesting
· Lift self-blanching varieties as required – finish harvesting before the frosts arrive. Remove the outer plants first, using a trowel so that neighbouring plants will not be damaged.
· Lift trenching varieties according to type – white types up to Christmas and the coloured ones in January. There is no need to wait for a sharp frost – there is little scientific evidence that frost improves quality. Start at one end of the earthed-up row – replace soil to protect remaining plants.

Varieties
Trench varieties
These varieties are not easy to grow, as trenching and subsequent earthing-up are time-consuming jobs. Choose from this group if you are an exhibitor or if you have rich, deep soil and like a challenge. Otherwise grow self-blanching celery. The white trench varieties have the best flavour but are the least hardy. Grow pink or red celery if you want a New Year Crop.
Giant White: The traditional white-stalked celery, tall and crisp and full of flavour, but demands good growing conditions. Various strains are sold by seed suppliers – you may find Solid White, Hopkin’s Fenlander or Brydon Prize White in the catalogue. Prizetaker is a popular choice for the show bench.
Dwarf White: A short-growing variety which needs less careful blanching than Giant White.
Giant Pink: A hardy variety for use in January or February. The crisp stalks form a solid heart and the pale pink sticks blanch easily. It may be listed as Unrivalled Pink – the strain Clayworth Prize Pink has a good reputation.
Giant Red: Hardy and strong growing – the outer stalks are purplish-green, turning shell pink when blanched.
Standard Bearer: A red celery which has the reputation of being the latest of all to reach maturity. Not popular – you will have to search to find it.

Self-blanching varieties
These varieties have taken some of the hard work out of celery growing. They require neither trenching not earthing-up, and they mature before the end of summer. They are milder-flavoured and less stringy than trench varieties, and they are not winter hardy.
Golden Self-Blanching: The basic yellow variety – low-growing and early maturing with a fair but not outstanding flavour. Ready for cropping, like the other yellows, from August.
Lathom Self-Blanching: A better choice than Golden Self-Blanching if you want a yellow celery. It is less likely to bolt and the flavour is better. The hearts are tender and stringless, but all self-blanching varieties should be eaten on the day of harvesting whenever possible.
Celebrity: A new variety, claimed to be an advance on Lathom Self-Blanching. All the good properties are there, but the sticks are longer.
American Green: The basic green variety – solid hearts, pale green stalks, crisp but stringless. Ready for cropping from October. The popular strain is Greensnap – there are others, such as Utah.

Troubles
Celery is not an easy crop to grow successfully, and its culture is made even more difficult by four serious problems which can plague this crop. Three of these problems are easily noticed whenever they occur – celery fly, celery leaf spot and slugs. The fourth problem is shortage of water, and here the effects are less obvious but no less devastating. Prolonged dryness at the roots will invariably lead to the production of plants with inedible hearts.
Celery Fly (Leaf Miner)
Celery Leaf Spot (Blight)
Bolting
Celery Heart Rot
Splitting
Slugs and Snails