Growing Your Own Vegetables - Celery
16th May 2002
Celery (Apium graveolens) is not the easiest of vegetables to grow well as it needs a fair bit of attention, initially in thoroughly preparing the growing plot and afterwards in looking after it. Celery has been around since ancient times, indeed in ancient Greece it was utilised to adorn the heads of athletes as well as being used as funeral wreaths before it ever became fashionable to eat as a vegetable during the middle ages. Although Celery is rich in a variety of vitamins, mineral salts and iron it's very low in calories and seems to be a vegetable that you either like a lot or are totally indifferent to it.
Sowing Celery Seeds
The seed of celery are the smallest of all the vegetable seed having as many as 70,000 seed in one ounce and tends to be rather difficult grow initially as it can take anything up to three weeks to germinate. In it"s natural habitat it's a bog type plant and from that we can instantly gather that it loves moisture, therefore from the day it germinates in your seed tray it should never lack water. Sow the seed anytime from mid March to mid April by broadcast sowing, as thinly as you possibly can, on top of some fine seed compost in a shallow seed tray and cover over lightly with the same compost. Over the past few years I have had better germination when using fine Vermiculite to cover the seed as the young seedling seems to emerge through a lot easier.
Place the seed tray in a propagator or on a heating blanket or soil warming cable as it certainly requires an even temperature of around 60°F. It is often suggested that a pane of glass is placed over the seed tray until germination. I prefer however to leave the tray uncovered and daily give the surface a fine mist spray of water to maintain moisture. Once germinated and when showing what we call the rough leaf or the true leaf, it can be transplanted into small cells such as plantpak 24s (24 independent cells attached together to fit into a large seed tray) or a 3" pot using a suitable Multi Purpose Compost. If the plants have been grown well they can be further potted up into 4 or 5 inch pots and should be ready for hardening off during early May and planted out anytime now.
For the very best heads, thorough preparation of the soil is essential during late Winter or early Spring incorporating plenty of compost or farm yard manure which will assist in keeping the bed moist. Make sure that your soil is not acid, aim for a neutral PH and apply a base fertiliser dressing forked into the top 6 inch layer prior to planting out. I have used many types of fertiliser during my gardening career and although Growmore has all the macro nutrients that the plants require, I do prefer, particularly with celery, to use a fertiliser that has a wide range of Micro or Minor trace elements added, such as Chempak BTD, Vitax Q4 or the newer Hydro Complex Partner.
Types of Celery
There are basically two types of celery, self blanching and trench, self blanching means what it says, the plant does not require earthing up or collaring prior to harvesting whilst the trench variety does. If you fancy having a go at exhibiting your celery then the Trench variety such as 'Ideal' is inevitably the one that picks up all the Red cards. Self blanching varieties fall into two classes, the white and the green although there are still a few pink or red varieties available and these tend to be hardier then the others. Victoria is a well established type giving you a very high petiole count and was the first British bred F1 hybrid variety. Another good one is Golden Self blanching 3 or Crystal, a strong variety that grows quite tall.
If you are growing for exhibition you inevitably plant the celery in straight rows as it is a lot easier to gain access to the plants when it comes time to collar them. The self blanching cultivars need to planted in groups or blocks and the size will obviously be dependent on how much celery you like to eat. Generally a small area approximately a metre square will be sufficient and the plants need to be spaced out at 8 to 9 inches apart each way. Growing the plants close together effectively pulls the plants upwards in search of light thereby lengthening the stalks making them tender. I have had even better success by pushing 4 stout canes at the four corners of the bed and then wrapping some builders damp course material, 9 inches wide around it. This makes sure that even those heads around the outer perimeter are just as tender and succulent as those inside the block.
Watering and Fertilisers
Never allow the celery to go dry, give it copious amounts of water during hot sunny days as well as a balance feed of liquid fertiliser. Towards the end of the season I like to give it some Phostrogen which has a higher ratio of Potash thereby slightly hardening up the plant and increasing the flavour. Once the plants are visibly growing away, keep a sharp look out on the foliage for any blistering.
Celery, as are Parsnips, their close relative, are prone to the Celery fly that produces tiny little white maggots that tunnel within the leaves causing them to blister, the simple answer to remove the affected leaf as soon as it is seen. Another pest of the celery are slugs, if they are not kept under control by using some slug bait, they can seriously devastate any young seedlings.
A bigger problem, particularly with the trench variety, is that the heart of the celery can very suddenly turn into a slimy brown mess destroying any chance for the plant to produce any more stalks or petioles from the centre. This is not a disease but rather a cultural problem brought about in the main because of the way we grow it. In the case of self blanching the plants being so close together causes the young tender shoots in the middle to sweat and go rotten. The problem is lack of calcium at the young tip or shoot causing it to totally collapse and rot off. This does not mean a lack of Calcium in the soil, it has nothing at all to do to do with the soil P.H.
A few years ago, when trying to grow celery very early for my Chelsea display, it took me three years before I could produce suitable heads. The main problem being the heart rot as they were grown singly in pots and also In a warm greenhouse as well. To cure the problem I now give each plant, every ten days a heaped teaspoon of Calcium Nitrate in a gallon of water. This is then trickled down the stalks into the heart thereby giving the young shoots the calcium they need to harden up, since using it I have, more or less, completely eliminated the problem of heart rot.