A Guide to Growing Organic Tomatoes

organic tomatoes

organic tomatoesNothing tastes quite like summer that a salad of freshly picked home grown organic tomatoes, sliced and sprinkled with basil and olive oil. A glass of chilled Corbieres Rose is a lovely companion, as are good friends to share them with.

This is not intended to be a definitive guide to growing organic tomatoes, more it is the summary of my experiences, what I have learnt works in my environment here in the Haut Corbieres.

Preparing to Plant Tomatoes

As with so many plants most of the work for organic tomatoes is in the preparation. Tomatoes are hungry chaps, and need a good 30 cm depth of rich soil, rich in vegetable matter and a good balance of minerals as well. They like a Ph level 6 -6.5. As the tropical plants they love a combination of warmth and humidity, so a sunny spot with easy access to water, ideally a drip by drip watering system that delivers the water direct to their roots. Also think about ground coverage, a rich mulch protects the soil underneath from the sun, reduces the water evaporation, and feeds the soil as it decays.

They also need space as they are vociferous creepers. There is a school of thought that tomatoes should be left to spread along the ground, as they would do naturally in the wild. I have seen some pretty amazing results from this technique but there are a couple of problems in my opinion with this method, firstly you need a lot of space, a luxury most people don’t have, secondly low lying plants can be susceptible to early blight, (Alternaria solani) which is a right royal pain, Although there are a couple of organic solutions it better to not have the problem in the first place. That is why I recommend training them up a structure. I use squiggly metal poles or reeds that I cut from the river bank-the latter have to be replaced every year. Growing against a fence or lattice can work well, particularly for large fruiting varieties like Beef Hearts, where you can support individual bunches.

Planting Tomatoes from seeds

Tomatoes can be easily grown from seeds, particularly if you have a sunny window sill, conservatory or greenhouse. Start planting in early Spring, if you are planting a lot of the same variety it is not a bad idea to stagger the planting, in an attempt to try and stagger the harvest, sometimes it works sometimes the later planted seeds catch up with their older siblings. Plant the seeds individually so you don’t have to separate them out later. Old loo roll centres are perfect, just cut them in half, you can plant them entirely as the cardboard will dissolve in wet soil, yogurt pots are about the right size as well.

Planting out Tomatoes

First a word of warning, don’t rush it. You may be eager to open that Rose and invite the neighbour round but tomatoes are very susceptible to frosts, they are tropical plants after all. Because we don’t heat our poly tunnel, and live at 400m altitude our tomatoes are always a bit later than our low land colleagues with their heated tunnels. However we never lack in clients, often folks who planted too early and have lost their first plants and are re buying. Wait until you are sure that the last frost is well and truly behind you before venturing out with the young tomatoes plants.

It is not a bad idea to harden them off a little before planting, take them outside and show them the sunshine for 4 or five days, bring them back in on an evening. This is particularly necessary for bought in plants, chances are they have been forced in a heated green house and will take a little time to get use to their new environment. If you have bought them off a grower direct have a chat with her or him and find out how they were raised. That is the great thing about buying direct, the grower can tell you about the plants history and their experience about what works and what doesn’t. You may spot a bit of bias in that last bit, but but hey, it is how we try and make our living.

Plant about 20-25 centimeters apart, with a similar distance between the rows. Plant them as deeply as you can, don’t worry about the bottom couple of sets of leaves, pinch them out- better to pinch them with you finger nails than cut them off, the wound are better sealed that way. The deeper the root ball is the better the foundation of the plant, and the less risk of them drying out.

As the heat and water take effect the plants should shoot up, do not worry of they do take a little time to get going, it takes a cople of weeks for them to get use to where they are, and just because they are not growing above the surface does not mean that they are no growing below the surface.

A note on watering.

Tomatoes are thirsty, but they drink slowly and continually, what they don’t like is change. You need to set a watering regime and stick to it. If you water by hand like I do, a morning watering around the base of the plant, giving each plant around 5 litres of water, is sufficient, in full Summer when the plant is starting to fruit I add an evening watering as well, I wait to the full heat of the day has passed, just before what we in France call the aperitif hour, and then reward myself with a drink on the terrace. As already stated a good ground covering mulch massively help reduce water loss as well as keeping the soil cooler in Summer and warmer in Spring. It also helps keep weeds down.

On going care for Tomato Plants

As previously stated tomatoes are hungry folks, a mid season composting round the base is always a good idea, a lovely nettle tea helps replace much needed NPK. I prefer these first two as they are cheaper than applying bought organic fertilisers, but if money is no object you can pop that on too. For me the ideal time is when the plant is starting to form fruit, that is when they needs a little boost.

Keep an eye on your plants, there are three major headaches to look out for.

  1. Early blight, Alternaria solani ,the low leaves develop brown spots with black rings around them. If you see that prune them out. And thrown them away, do not put them on your compost, it is a type of fungus that will infect your compost pile.

  2. Caterpillars, particularly tomato hornworms, the larva of a moth. Physical anialation is the best solution, it’s a messy job but it is either them or your tomatoes.

  3. Late Blight, Phytophthora infestans, can hit after a long wet period. This is a right horrible one, leaves brown off and the entire plant just collapses. The best solution is preventative, keep the plant well pruned so lots of light can get through and helping make sure that the plant stays dry. On that one, if you don’t have the luxury of a watering system, make sure that when you water the plant you water around the base of the plant and not on it’s leaves.

Pruning Tomatoes

Tomatoes once established, with the right heat, soil and water grows like crazy

Again various schools of thought in this one, there is the natural school that believes that the plant should be left to do it’s own funky thing, this gives you, with the right soil a huge bush, rich in foliage and, I find, light in fruit. I follow my grandfather’s advice on this one, he firmly believed that each tomato plant could give only so much fruit per plants, and to ask for more was just been greedy. A strong tomato plant, depending on variety, can give between 5 and 7 kilos of fruit in a season. That equates to between 5 and six bunches of tomatoes per plant. Each bunch needs light to help ripen but not too much. So with this objective in mind the plant should be pruned carefully and regularly. A tomato will try and push out side shoots from the V between every leaf branch, these should be pinched out with the fingers when tiny.

Pruning the foliage. Once the tomato plant has started growing I take out the bottom leaves to minimize the risk of early blight. Do not let any leaves touch the ground, I go one further and take off any leaves in the first 15 cm of the stem.

There will come that moment when the plant starts to flower, in indeterminate varieties this happens over a period of Summer rater that all at once like determinate varieties. I let seven bunches of flowers form. I only let six give fruit as I think that is the limit a plant can give, but I often find that one bunch does not set the fruit right, often the lowest flowers. The one that does not set gets the chop. Once the fruit has set and the tomatoes have grown to a decent size you may want to cut back a little of the foliage to allow the sun to get to the fruit, in my experience it is not really necessary. Too much sun during the ripening period can actually cause problems, the key issue is on keeping the humidity levels constant and keeping the essential nutrients topped up. This guide by Jeremy Dore How to Identify and Corect Tomatoe Nutient Deficencies on nutrient feeds to aid fruiting and prevent diseases is the best advice I have ever read and you could not want for better.

Companion Planting

Companion planting is a much loved organic horticultural method. The idea is that some plants benefit by being grown in association with others. Whether it be the nutrients that some plants set in the ground, the shade that one plant offers another, or the effects of the aroma of one plant in protecting it’s neigbour from insects or illnesses.

Tomatoes are sociable types, the shade they offer helps herbs that are quick to go to flower in the full sun develop into delicious bushes. To this end I always plant basil between my tomatoes, the aroma of the basil helps hold of insects, the shade of the Tomatoes slows down the flowering process of these delicate annuals, they have the same water needs, and of cause they taste delicious together. Tagetes, a variety of Marigolds, produce alpha-terthienyl , a chemical that helps prevent root-knot nematodes.

I also plant parsley and coriander, not for any benefit for the tomatoes but because they flower too quickly in Summer and the shade slows them down, some people say that borage is good to control root worm, I have no idea if this is true, I can not find any scientific evidence to back up this claim, but there is no harm in planting it in early Spring, chez nous it tends to grow early then disappear in full Summer. Planting comfrey; which can be trimed three to four time a year, you just leave the chopped leaves in place is a great sourcer of nitrogen and potash for the soil.

Last Note on Tomatoes

After you have spent a lovely Summer mulching away on fresh tomatoes, sipping Rose and solving the problems of the world with friends, it is time to say goodbye to your tomatoes. They need to be dug up, and the plants thrown away, not composted, this reduces the risk of disease being passed into the compost. The now empty patch needs a good cover of compost and mulch to replenish the nutrients and vegetable matter in the soil. Planting clover or mustard can help keep down weeds and can be strimmed to add their goodness to the soil.

If you look after the soil at the end of the season it is less work for next Spring, and it also means that you can avoid having to rotate crops. Crop rotation is a good idea for large scale production but the research is unclear whether it works on small scale vegetable gardens, better to work with the soil to produce the ideal growing medium for each type of vegetable across the patch than try to alter the soil type every year.

And then next year it starts all over again.

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