Growing Celery in Scotland: The Complete Guide

Apium graveolens var. dulce

Celery asks for steady moisture, a late start outdoors and regular attention, and most growers now choose self-blanchingExcluding light from part of a growing plant, usually by earthing up, wrapping or covering, so it grows pale, tender and less bitter. Full definition → types instead of digging a trench.

Celery has a reputation as a fussy crop, and the reputation is earned. It never forgives dry soil or an early planting date. None of that is a reason to skip it, but it is a reason to know what you're taking on before you sow.

Choosing a type

Self-blanching and green varieties are what most growers choose today: planted in a block so the plants shade each other, with a paper or cardboard collar doing the rest of the work. Trench varieties, the traditional kind grown in a dug trench and earthed upDrawing soil up around a plant's base as it grows, most often potatoes, to keep light off developing tubers and support tall stems. Full definition → through the season, are rarely available at all, and slower and trickier to grow well. Choose self-blanching unless you specifically want the trench method for its own sake.

Preparing the ground

Celery wants a sunny site with fertile, moisture-retentive soil, ideally prepared the autumn before: dig in plenty of well-rotted manure or garden compost to help the ground hold water through summer. For a trench variety, dig a trench and refill it with a compost-and-manure mix before planting.

Sowing

Sow indoors only, mid-March to early April: celery seed needs light to germinate, so scatter it thinly on the surface of peat-freeCompost made without peat, which is harvested from a slow-forming, carbon-storing wetland habitat that peat extraction damages. Full definition → compost rather than covering it, in trays, modulesA tray divided into small individual cells, each sown with its own seed or seedling, so each plant grows undisturbed roots until it's ready to plant out. Full definition → or small pots. GerminationA seed sprouting: breaking dormancy and putting out its first root and shoot, given the right warmth and moisture. Full definition → needs at least 15°C and can take up to three weeks. Prick seedlings out into individual 7.5cm pots once they're large enough to handle.

Planting out

Plant out in late May to early June, once the risk of frost has passed and plants are well hardened offGradually getting young plants raised indoors used to outdoor conditions over 7–14 days before planting out, so cold, wind and direct sun don't shock or damage them. Full definition →. Wait until night temperatures are reliably staying above 10°C: this is a cold threshold, not just a frost one, and celery chilled while young is liable to bolt. Cover with clochesA small, portable clear cover placed over an individual plant or short row to trap warmth and keep off wind, rain and pests. Full definition → or fleeceA lightweight, breathable fabric laid or draped over plants to trap a little warmth and keep off frost, wind and some flying pests. Full definition → for extra insurance while plants establish.

Space self-blanching varieties 23cm apart in each direction, planted in a block rather than rows, so the plants shade each other's stems. Trench varieties go in single rows 30-45cm apart. In containers, use the same 23cm spacing in a large pot of peat-free multi-purpose compost, sited somewhere sunny and sheltered; containers dry out fast and need generous, regular watering all season. Water thoroughly at planting, and watch for slugs straight away.

Varieties

The RHS growing guide lists Tango, Victoria and Tall Utah 52/70 with the Award of Garden Merit, a UK-wide award rather than a Scottish one, though their own plant pages show no badge. Granada is worth considering for its resistance to celery leaf spot.

'Tall Utah 52/70' is tall, high-yielding and stringless, and 'Lorreta' is self-blanching, British-bred and reduced in stringiness.

Also worth considering

Best Celery Varieties for Scotland → compares all named celery varieties head-to-head, with the practical detail that doesn't fit in a summary card.

Care

Keep the soil consistently moist throughout. MulchA layer of material spread over the soil around plants to suppress weeds, retain moisture, and improve soil structure as it breaks down. Full definition → thickly with compost or well-rotted manure once plants are established to help hold that moisture and keep weeds down, but leave a gap right around the base of the stems so they don't sit in wet mulch and rot. If the ground was well prepared, feeding usually isn't needed; on poorer soil, a light dressing of high-nitrogen fertiliser once plants are established gives them a boost, and container plants do best fed fortnightly with a balanced liquid feed through summer. Weed regularly and by hand near the plants: celery grows slowly at first and is easily swamped.

Blanching: in mid-to-late summer, once stems reach about 30cm tall, tie a sleeve of newspaper or corrugated cardboard around them, leaving the top third of the plant exposed to light. Only the outer plants in a block strictly need it; wrap every plant instead if you want all your stems milder and sweeter. Trench varieties are blanched by gradually mounding soil around the stems through late summer instead, or with the same paper-and-cardboard method.

Harvesting

Self-blanching and green varieties are ready from mid-summer to autumn, roughly 25 weeks after sowing: harvest as soon as they reach a usable size and before the leaves start yellowing, since the stems turn stringy with age. Most types aren't hardy, so cover with cloches or biodegradable fleece as night temperatures fall, and finish harvesting before the first frost. Trench varieties take longer, around 40 weeks, cropping from late autumn to early winter and tolerating a harder frost with fleece protection. Lift whole plants as needed and use them promptly.

Common problems

• Slugs and snails are a risk to this crop.
• Stringy, over-strong stems are usually a watering problem rather than a variety fault: celery is mostly water and shows a missed watering directly in the eating quality of the stem.
• Bolting follows chilling while plants are young, with nights below 10C for more than 12 hours. Keep plants under cover until that threshold passes reliably, harden off carefully, and protect with cloches or fleece for a few weeks after planting out.

Common questions

Sources