Hi Gareth
"Trench" celery is the name used to describe the method of blanching the stems. This is accomplished by earthing up the base so that they do not have the green colouring of the stalks. This type is very hardy and is harvested late autumn to early spring. There are newer varieties that are self-blanching, but are less hardy and have a shorter growing season.
Trench celery is divided into the white, pink, and hardier red varieties and include the following:(I doubt we get many of these here though)
Giant Pink has crisp pale pink stalks that blanch easily.
Giant Red has outer stalks that turn shell-pink when blanched.
Giant White is an old, tall, white celery with crisp stems and a solid good flavoured heart.
Hopkins Fenlander is a late maturing celery of medium length and free from strings.
Standard Bearer is a red celery that has the reputation for being the latest of all to reach maturity.
Self-Blanching celery varieties are as follows:
Celebrity is an early maturing variety that has crisp long stems and a nutty flavoured heart. It is one of the least stringy self-blanching varieties with good bolting resistance.
Golden Self-Blanching has golden-yellow hearts, and is crisp and tasty and does not become stringy.
Greensleeves produces tasty green stalks.
Ivory Tower has long white stringless stems.
Lathom Self-Blanching is a vigorous well-flavoured variety with crisp stems.
Tall Utah Triumph has long succulent tender green stems.
Caution: Celery contains limonene, an essential oil known to cause contact dermatitis in some people. This oil can also be found in dill, caraway seeds, and the peel of lemons and limes. Another precaution is the furocoumarins (psoralens) that are released by damaged or moldy celery. These chemicals are photosensitizers, as well as potential mutagens and carcinogens. Contact with these chemicals can cause skin problems in those who are sensitive. (cheers
www.innvista.com/)
(Are you stocking any celery seed)
Garden galore at gardenplans gives a few good pointers about wooda ash
If you garden on an acid soil like I do, turf or wood ash works wonders for all the rose family (roses, fruit trees, pyracantha, chaenomeles etc). They need the alkalinity to free up potash in the soil; and thats another ingredient...potash....hence the name. It works wonders for disease resistance, and flower/fruit production. A could dollop of DRY ash around them in Spring is best. Rain washes the active ingredients out of ash very quickly.
Put please keep it well away from your lime-haters. (rhododentron, erica, arbutus, and quite a lot more, best to keep the ash to rosaceae)
One more word of warning....Beware ash contaminated with coal, paint or plastics... it could contain plant toxins.
Cheers