Exhibition Celery, Onions and Tomatoes
7th Apr 1999
There's no doubt that last Summer was a good one for growing exhibition celery; there was plenty of moisture around and it didn"t get too hot for the heart to sweat and rot away. Mine only grew well late on, mainly because they were in two new raised concrete block beds that were only completed as late as the end of March and really didn't have enough time to settle down. This year I have only one of those beds for growing celery and the other is being utilised to grow a number of different varieties of short carrots.
My first sowing is now ready for moving on into their final pots which are 5" square plastic and these have served me well over the years. The mixture this time will be based on the John Innes formula having taken heed of Bob Herbert's advice that celery prefers a soil based medium to a peat one. This came about because a number of my plants when grown in Levington M3 only were having heart rot, even at the final pot stage and the roots were noticeably brown as well. Since I have converted to a soil based mixture the problem seems to have been eliminated.
Celery are certainly a hungry and thirsty crop and as they were a bog plant in their own environment in the wild, they must not be allowed to go dry at any point as they could run to seed later on. Once the plants are growing away in their final pots, make sure that the stalks are kept upright and not allowed to fall around and left to their own devices. The lower thin split stalks can be removed and don't forget to scatter a few slug pellets around.
The method I use for supporting the stalks is two split canes and plastic plant support clips which form a complete circle encompassing all the foliage. These clips can even be used when the plant is first transplanted out into their beds, by using three or even four split canes. The clips can be utilised from one cane to the other to form a fairly large cage to contain the foliage at its initial stage.
The onions for the under 8 ounces class are now in 3" pots and are nearly ready to be potted on into 5" pots and from there into their final pots of 7". The compost for the 5" pot will be as follows : 4 parts Levington M2 two parts of sieved soil from last years leek bed and 1 part fine Vermiculite as well as 1 ounce of Chempak potting base to a bushel of mixture.
The 7" and final pot mixture will be exactly the same as the one Ron Macfarlane has used with great success, 4 parts of Levington M3, 4 parts of soil, again the soil that was sieved from my leek bed at the back end of last year, and 1 part Vermiculite. As the Vermiculite ratio is an inert material and has no food value at all the nutrient levels have to be increased accordingly and Ron does this in the final potting stage by adding 2 ounces of Chempak BTD (base top dressing) to every bushel of mixture.
The plants in the 7" pots will be grown throughout in the greenhouse on my growing bench which has a fan at one end to blow and move the hot air around whilst another is positioned at the opposite end to draw the hot air out. Whilst growing, the leaves will be supported throughout by using plant support clips. A number of onions this year will also be planted directly into one bed in my polytunnel, the bed is only about ten foot long and 3 foot wide but I should be able to plant three rows at 10 inches apart to give me 36 onions.
These onions for the under 8 ounces or 227 grams class if they are to be judged in accordance with RHS rules and 250 grams or less if judged to NVS rules; do not require half the spacing of their big brothers as they will be pulled when only around the 10½ circumference (depending on shape) The bed has already been prepared and the onions will be planted out next week directly from their 3" pots with no need for any further potting on. The variety in the beds will be Bison which has aclearer more pronounced veining in the skin than Toughball which will be the variety that I shall grow on in the pots.
Your tomato plants should be really growing away now with the longer day length making a noticeable difference. The one very important factor with growing tomatoes at this stage is to give them plenty of room on the benches, make sure that the leaves are just touching each other in order to maintain as sturdy a plant as possible. Any leggy plants will grow away fine, but it does mean that your trusses are going to start higher up and in the average amateur greenhouse it's an important factor as the height to the eaves can often be rather low.
If you have a cold greenhouse you can now purchase some plants. Do make sure though that they are not leggy and drawn, that they have a lovely bright green colour and stay clear of any plants that have yellowy purplish bottom leaves; these will have had a check in one way or another and will inevitably take time to grow out of it. Be still wary of frost and when you bring them home, leave them on the bench for a couple of days to acclimatise prior to either planting them or potting on and do have some fleece ready to throw over them should there be a frost warning.