The Tomato is the one of the most popular edible crops grown by the British Gardener. The reason is probably because, even if you don’t have a Garden, you can still produce a reasonable tasting of this delicious fruit with just a window box or even a hanging basket when growing tomatoes.
For the amateur Gardener there are several different ways to produce a crop:
Heated Greenhouse. Cold Greenhouse. Open Garden. Patio. Hanging Basket.
All of these different methods involve the same basic cultural demands.
This method of growing Tomatoes will ensure that you will be able to produce a really early crop; which means that you will be eating the fruit when they are still at a high price in the shops.
The time to sow your seeds is in late January or very early February. At this time of the year the light levels are very low, and the Tomato plant really does thrive on sunlight, so you may need to supplement the natural day light with some artificial light. There are several ’Light Boxes’ on the market that can greatly assist you with this; However, I must advise that this is not absolutely vital, but it will help.
The compost used for sowing the seeds needs to be completely sterile and free draining; because the plants will be a little weak due to the lack of light. I would recommend sowing thinly in a seed tray, partly to save space, but also the young seedlings will be easier to manage.
Once the seedlings have produced their first ‘true leaves’ it is time to move them on into small individual pots. Remember, these little plants are very fragile, handle with the utmost care; hold the plants by their leaves, not their stems. Again, use a free draining, sterile compost.
The best temperature for raising the young plants is 17 degrees C night time and 19 degrees C daytime. Be sure that the general temperature is in line with the light levels – hotter when bright, cooler when dull. When the plants have reached a reasonable size, say 15-20 centimetres tall and have a number of mature leaves, it is time to move them into their final cropping position. This will be achieved in late February or early March. At this stage there might even be the first sign of a flower truss.
There are various methods of growing Tomatoes in heated Greenhouses. There are Growbags, Pots, Ring Culture, Straight into the Soil or Hydroponics.
Growbags: This is very popular method is simple and quite reliable. Make sure you purchase really good quality Grow Bags – they will have to endure quite a lot of hard work! Which ever method you use to grow your crop you will need to support the plants as they grow. The main methods used are Bamboo canes or String.
Bamboo Canes need to be well secured to the Greenhouse structure as they will carry quite a lot of weight! If you are using Growbags then this can be difficult, I would therefore recommend using String. Make sure the String is well fixed to the Greenhouse glazing bars. If your Greenhouse is made of Aluminium you can purchase special clips that fit into the bars and will allow you to fix the string securely. If you have a wooden Greenhouse, then put some strong screws in to the glazing bars to hold the strings.
Fix the String and then plant your Tomatoes in the Growbags directly under the String. As the plant grows you will wind the stem of the plant around the string and this will happily support the plant quite securely.
The same procedure applies if you are growing in Pots. The pots need to have a capacity of at least 20 litres – more if possible. The compost you need to put into these pots should be either high quality, peat based multi-purpose compost or multi-purpose compost with John Innes.
If you are planting straight into the Greenhouse soil, then you must be sure that the soil is very fresh and as sterile as possible. If you have grown Tomatoes in the soil before, then I would strongly recommend that you leave a gap of at least 3 years before growing another crop.
Spacing of the plants is important. Too close together and the crop will be difficult to manage, and the quality of the fruits will not be very good. The plants need to be at least 30 centimetres apart in the rows, with at least 60 centimetres between the rows. Air flow and sunlight are vital ingredients to the crops success.
Hydroponics is the culture of Plants without using any basic soil structure for their roots. It is a complicated and quite exacting method of growing, and for this reason I am going to treat it as a separate subject for another occasion.
Similarly, Ring Culture is another specialist method, and not unlike Hydroponics; so we will address both methods at some future time.
Back to Growbags. – The following process also applies to growing in pots using a good quality multi-purpose compost- There will be some planting instructions printed on the Growbags; follow these instructions, but also bear in mind that your young plants must be planted firmly in the bags or pots and must not be buried too deeply – no deeper than the existing level they are at in the pots.
Once planted, I always give the plants a nice watering, using a watering can with a fine hose. This action settles them in nicely. Again, the ideal air temperature is 17 centigrade at night and 19-20 C. in the daytime, but still try to balance the sunlight with the temperature.
We are now entering the Spring, and the days will be getting longer; you will notice the rate of growth increasing quite noticeably. It is time to guide your plants up their string supports. You should need to do this every 4 to 5 days. As the plants grow you will need to start ’Side Shooting ’ operations!
Side Shooting is the practice of removing the shoots that will grow from the junction of the Leaf and the Main Stem. By nipping out these little shoots you will direct the energies of the plant into making large trusses of Fruit. You are, in effect, growing a ’Cordon Plant’ This term refers to any plant that is restricted to a single stem in order to maximise the initial flower/fruit of the plant. Be careful not to remove the Flower Shoots that will start to appear between the leaves on the main stem.
Your plants will now grow ever upwards!
Feeding with Liquid Fertilizer will commence as soon as you see the first tiny Fruit beginning to form; this will be some time in early April – or even late March!
Liquid feeding will continue on a weekly basis for the rest of the plants productive life. You will probably have heard of ’Tomorite’ This has been the staple tomato feed for generations of Tomato Growers. It is undoubtedly a very good fertilizer, and easy to use, however there are others and I would like to mention. Phostrogen Tomato Liquid Fertilizer is very good. Maxicrop Organic Tomato Fertilizer is a seaweed extract plant food and has the added benefit of giving your plants some degree of disease resistance.
Follow the manufacturers instructions on feeding, which ever Food you choose.
Regular watering is very important during the summer months. Because of the size of the plants relative to the area of soil they are planted in, there will be little or no reserves of moisture, therefore watering needs to be monitored on a daily basis.
Ventilation is another important factor for successful Tomato Growing. If the weather is fine and sunny then open the greenhouse vents as much as you can. Even if the temperature is not that great outside, you will still be better to leave plenty of air circulating around the plants. An Automatic Ventilating System would be ideal.
Eventually your plants will reach the roof of the greenhouse and you will have to cut short their upward growth. In commercial Tomato production the Cordon Stem of the Tomato is taken down from it’s string support and laid down along the row as far as it will go, and then sent up another string support; all the plants in the greenhouse are treated in this manner and so you have a great circle of plants along the ground and up in the air!
In the domestic greenhouse this would be difficult to achieve, so it is better to simply stop the plants and let them concentrate their energies on producing as much fruit as possible from the existing trusses.
The leaves that remain on the stem will start to look a bit ‘tired’ now. As you think they are well past any useful purpose ie very yellow and curly it is better to remove them by cutting them off about 5 centimetres from the stem. This trimming process will start at the base of the plant and gradually progress upwards as the plant gets older.
You will notice a bit of a phenomenon when you have been doing work with your Tomatoes; when you come to wash your hands afterwards you will see a great deal of ‘green’ water come away with the soap, this is the chlorophyll contained in the skin cells of the Tomato and indicates that this particular plant just loves lots and lots of sunlight!
Your plants will probably finish cropping in late August, when the last of the fruit is ripe and has been harvested. Time now to clear away the old haulms onto the compost heap or into the compost bin and make room for your next crop. This could very well be winter flowering Chrysanthemums. If you have used grow bags or pots, then the spent compost can be put on the garden as a soil improver of mulch, however, a word of caution, only use this compost where you are NOT going to grow potatoes in the future , as there may be a danger of ‘Blight’ contamination.
Growing your plants in the soil in the greenhouse will require the same processes as the above, except watering will not be quite so critical as the ground will hold a reserve of moisture. Feeding, side shooting, tying in and trimming will be the same.
Growing in a Cold Greenhouse:
All the same processes apply as with growing in a heated greenhouse except that every operation is undertaken a lot later because of the danger of frost.
Because of the lack of heating it is more expedient to forget growing from seed, and start your crop by purchasing young plants. These should be planted after the first week in April; beyond this date it is very rare that the severity of any night frost will penetrate an unheated greenhouse.
Because of the shorter growing season for Cold Greenhouse culture it would be best if you limited the number of fruiting trusses to just 5. This will ensure that all the available fruit is able to mature fully, and ripen before the Autumn weather starts to bring in shorter days, and hence less sunlight.
Growing in the Open Ground:
Because of the frost danger, you will not be able to plant out in the open ground until the second week in May. Soil preparation is important. Tomatoes like a fertile, well drained, sheltered, sunny site. One important thing to remember is NOT to plant your Tomatoes in the same ground as you have been recently growing Potatoes; leave a gap of at least 3 years otherwise there may be a danger of infection from ‘blight’ or virus diseases.
Clearly you have a very short season in which to bring your plants to harvest. With this in mind it is better to only grow ‘Bush Varieties’ These varieties commence fruiting quite quickly and mostly produce small ‘Cherry’ type fruit.
It is possible to grow ‘Cordon Fruit’ but you will be limited to just 3 or 4 trusses. The big advantage of ‘Bush Varieties’ is that there is no side shooting to do, you just let the plants do their own thing.
Feeding is the same regime as greenhouse growing, watering will entirely depend on the prevailing weather conditions!
Patio and Hanging Basket Growing:
Because this is nearly the same as ’Open Ground’ growing you will not be able to plant out until May. Growing Tomatoes in containers on a sunny patio is a very satisfying way of producing something edible from an otherwise decorative area. Always use a good quality multi-purpose compost. I would also recommend that you only try and grow ’Bush Varieties’ Feeding regime is the same, but watering becomes very important, particularly when growing in Hanging Baskets; the container and baskets will dry out very quickly, even in rainy weather, so a daily inspection is most important!
Pests and Diseases.
The most common pest of Tomatoes is Greenfly. There are now pesticides that are derived for non-chemical substances. Bayer’s new Natria Bug Control is quite a good choice.
There are many Tomato Varieties and I would like to recommend the following which
have served me well over the years.
Ailsa Craig. Good yields and delicious flavour
Shirley. Heavy cropper and very good flavour.
Yellow Perfection. A really nice flavoured Yellow skinned variety.
Herald. Recommended by ‘Foodies’ as having the best flavour of Greenhouse varieties.
Lucciola. A delicious ‘Plum’ variety.
Marmalade. A great ‘Beefsteak’ variety.
Gardeners Delight. A very reliable and tasty ‘Bush’ variety.
Tumbling Tom Red and Tumbling Tom Yellow. Both these ‘Bush’ varieties are perfect for growing in Containers and Hanging Baskets.