Converting the Raised Bed for Trench Celery
27th Jul 2000
Earlier on this year I decided to convert one of the three raised beds that I have used regularly for growing short carrots, to growing the trench celery. A fair bit of work was entailed at the time as the beds were three foot deep full of sand and then good quality loam and some well rotted manure had to be brought in to form the new bed.
The main reason for changing the beds over was that this particualr bed was the one next to my leylandi hedge and therfore in a little bit of shade for some part of the day. This shading was not the best thing for the production of quality short carrots as they prefer to be in full sun as much as possible.
As a little bit of shade can be advantageuos to celery, particularly at the height of Summer when temperatures can soar upwards. To produce a good quality trench celery for the show bench doesn't mean that you actually grow it in trenches as used to be the style many years ago. The plants are actually planted at soil level and then collared upwards to exclude the light thus lengthening or drawing upwards the petioles or stalk whilst at the same time, very effectively blanching it. As the collars, particularly if using the black builders damp course has the effect of blocking out all the light, in hot days it can actually make the heart sweat and this sweating can eventually casue heart rot, so some shading is important.
Some of the top celery growers, Bob Herbert for instance, rather than change his bed has actually constructed a system whereby on hot sunny days he can roll over the top of the plants some fine black nylon mesh which helps to cool off the situation. As I said in some of my earlier articles, the celery were planted a few weeks earlier than normal this year and it certainly seems to have paid off as they are now very vigorous and tall and the first batch of plants are now on their final eighteen inch collars.
Initially after planting, the outer stalks of the plants were supported by creating a cage with split canes and green plant support clips which kept the whole plant upright without causing it to draw upwards too early.
During early June, after the plants were seen to be noticeably growing away, the canes and clips were removed and replaced by nine inch tall collars nine inch in diameter made from builders damp course were placed over each plant. The purpose of these collars were to gradually draw the plant upwards but kept loose enough for air to get at the heart but not too loose for the stalks to grow crooked.
After these collars were dipensed with during late June the first proper collars were placed on the first sowing and the material used for these was corrugated paper. This also blocks out the light but it also allows the plant to breath as well plus the fact that it soaks up water so the base area around the celery will always be moist. The first collar was fifteen inches tall and again rolled around the stalks of the celery at least twice to form a strong stiff cylinder. Do not wind the collar too tight at this time, you don"t want to suffocate the heart, you can draw the final collar in some three weeks or so prior to your show to really give you an effective blanch.
One other important consideration, when the plants are in their loose nine inch collars, position some strong four foot tall canes adjacent to each plant and at a point close enough so that it can remain there throughout the growing season.
From now on there are four important points to remember and these must be strictly adhered to:
Water is probably the most important element of all if you are to produce some top quality heads, and when I say water I mean plenty of it and at regular intervals. On a hot day my plants will receive two waterings so that the soil is always fully charged with moisture, don't forget, as I have said on numerous occassions before, celery is a bog plant in the wild and thrives on damp moist conditions, so never let it dry out.
The second point is to really watch out for pests, in particular the dreaded slugs, every time you open the collars to remove any split or yellowing stalks, apply a few slug pellets close to the base of the plant. After replacing the collar apply a further band of pellets around the outside of the collar. Also on a warm, dry but humid evening, apply some Murphys liquid slug killer called Slugit, this is particularly beneficial in controlling young slugs that might already have gone passed the first defence line of pellets.
The third point is to apply a high potash feed once a week for the last three weeks or so of growth, this will harden up the plants cell walls and assist in preventing heart rot. It will also help to increase that lovely pink splash around the base of the plant that looks so attractive and certainly catches the judges eye.
Finally, if you haven"t started already, continue with weekly applications of Calcium Nitrate, this proved to be a saviour to my celery for Chelsea this year as without it's regular use I most certainly wouldn't have been able to exhibit a single head as they would all have succumbed to the heart rot. Heart rot happens primarily because of lack of calcium reaching the young tips of the new centre growth and thereby rotting away. Apply the Calcium Nitrate through the watering can dribbling it in through the foliage so that it gets right into the heart. Continue with this application right through to the day you lift the heads.