Tomatoes

← Return to A to Z

Lycopersicon esculentum

Sustainable Ewe favourites:

  • Grosse Lisse (mid to large, red)
  • Brandywine Pink (large pink toned, meaty)
  • Baxter’s (red cherry, very heavy cropper)
  • Black Tule
  • Indigo Rose

History

Originating in Peru the first known tomatoes go back as far as 500BC. By 1521 they were in Spain, and from there spread throughout Europe reaching Britain around 1590. It was not until 1710 that they appeared in the USA, being classed as a fruit they were exempt from the 10% vegetable tax duty. Thus in 1893 they were re-classed as a vegetable in the USA.

Originally tomatoes were thought to be poisonous. Firstly due to it looking like Deadly Nightshade, and in 1692 it was indeed classified as being in the Solanaceae family along with Belladonna (Deadly Nightshade), an honour shared by peppers, potatoes, tobacco, eggplants and more. Add to this most flatware in early Britain (certainly for the wealthier classes) was made from pewter. Not only would this discolour the pewter but cause lead to leech from the metal, causing lead poisoning. It was believed that eating tomatoes would turn a persons blood to acid.

 

Growing

Technically tomatoes are a perennial, however they are very frost tender and so a treated as an annual. Grow in full sun in warmer weather (or in a greenhouse).

Because Tomatoes and Potatoes are both of the same family (Solanaceae) planting them in the same area or one after another should be avoided as they can pass on/share pests and diseases.

Tomatoes are susceptible to temperature fluctuations. A drop in temperatures could cause poor fruit set.  They do not like a temperature drop below 12 degrees or a rise above 37 degrees.

Place stakes in the garden before you plant your tomatoes.  Staking later may damage the roots of the plant.

Avoid high nitrogen fertilisers.

Water well, around 3-4 cm a week, and conserving water with mulch will aid in the production of healthy fruit.  Watering should be at root level – not foliage.

Stagger planting to avoid a tomato glut (unless you are hoping to make a LOT of sauce!)

Determinate vs Indeterminate:

Determinate tomatoes, or bush tomatoes are smaller varieties. They produce fruit all at once and then die off. They generally do not require a lot of staking or pricking out of laterals. These varieties are great for container growing.

Indeterminate varieties, or vine tomatoes will continue to grow and set fruit. These varieties will require staking.

Storing harvested tomatoes:

Room temperature out of direct sun.

Seed Saving:

Seed saving is particularly easy with tomatoes. Simply scoop the seeds out of a tomato and spread over a paper towel. Allow to dry for a few days then store in an air tight container in a cool, dark area. These seeds should keep for a few years. For longer lasting seed saving the fermenting method is recommended.

Easy way to peel tomatoes: Place in boiling water for 15 seconds then remove witha slotted spoonand plunge into ice water. Slit skins and peel off.

Tomatoes need warmth – not light to ripen. place out of direct sunlight in 18-21 degrees. Cover with a sheet of newspaper to help trap ethylene gas and hasten ripening. Check daily. An apple or a banana will also produce ethylene gas and aid in ripening.

Alternatively, pull the entire plant out and hang upside down in a shed or sheltered spot. Tomatoes should then ripen.

 

Maintenance

Feeding:

Tomatoes are considered gross feeders – They like a fertile soil, keep up a regular feeding and watering regime, especially when fruiting. However avoid fertilisers that have too much nitrogen.

Watering is best done at ground level to minimise fungal or bacterial problems. Make sure they get enough regular water especially in dry periods as lack of water can result in blossom end rot, inconsistent watering may cause the skins to crack.

Potassium levels are critical for growth and to prevent ripening disorders however too much potassium and the plant will be unable to take up calcium and magnesium.

Removing laterals and bottom leaves:

Laterals are the branches that appear at a 45 degree angle midway between a leaf and stem. These take valuable nutrients and resources away from the fruit. By pinching out (removing them) you encourage better fruiting.

Similarly, by removing the lower leaves of tall growing varieties air will circulate better and this will help prevent diseases.

Save these leaves! (See below on how to turn them into an effective organic Aphid spray)

Fun Facts

  • An excellent source of vitamins A and C, calcium and potassium. An excellent source of fibre
  • The original Aztec name translates as “Plump fruit with a navel”
  • Lycopersicum means “Wolf Peach”
  • Technically a tomato is a berry
  • China is the largest commercial producer of tomatoes
  • Tomatoes have been grown in space
  • There are around 10000 varieties of tomatoes worldwide
  • In Ontario, Canada 15th July is Tomato Day
  • Tomatoes are the state vegetable of New Jersey, but the state fruit of Ohio. Arkansas has hedged it bets making it both the state fruit and the state vegetable.
  • Tomatoes are rich in lycopene – good for your heart and your prostrate. Said to have cancer preventing properties.
  • Due to the misconception that they were entirely poisonous they were grown only for their looks in the USA originally.
  • Tomatoes in Italian: “Pomodoro” means ‘apple of gold’
  • Tomatoes in German: “Paradeisapfel” means ‘apple of paradise’
  • By 1920 tomatoes were in vogue in the USA – “Hot tomato” became slang for an attractive woman.
  • Tomatoes were once considered an aphrodisiac and were referred to as the apple of love
  • La Tomatina is a festival held in Bunol, Spain and is touted as the worlds biggest food fight. In previous years upwards of 50000 people would gather and throw over 100 tonnes of over ripe tomatoes at each other. Since 2013 the number of people attending has been limited to 20000

Problems

Blossom End Rot – Dark brown hollow patches form on the bottom of fruit. Caused by inconsistent watering, lack of calcium – As water is used to transport calcium through the plant without sufficient water the cells in the blossom end of the fruit begin to break down. Once the problem has occurred it is difficult to fix, however try to maintain a regular watering schedule.

Fruit Split – Caused by fluctuating temperatures or water supply. Avoid giving almost ripe tomatoes a long soaking

Greenback -Fruit does not ripen and remains hard. Often caused by plant becoming too dry followed by too much water or too much sunlight and high temperatures.   Water regularly.  Apply Sulphate of Potash.

Late Blight – Brown patches appear on the leaves and can spread quickly throughout the plant. Thrives in a humid environment. Caused by an organism similar to fungus.  Add 1 teaspoon of Baking Soda to a litre of water and spray the effected plants.  In severe cases removal of affected plants may be necessary.

Early Blight – More common in warm, wet weather. Remove affected plants

Verticillian Wilt – Leaves turn yellow and wilt and spreads to entire plant wilting. Caused by a fungus attacking roots or the base of the stem, often if the weather turns cool. Remove plant immediately to avoid spread. Crop rotation is important

Botrytis, grey mould – Leaves and stem and fruit develop grey/brown rot or mould. Remove affected plants. Space adequately. Prune to allow ventilation.

Leaf mould – older leaves get yellow blotches. Grey mould forms underneath. Young leaves have pale circular spots.

Bacterial Spot – Black specks on leaves, often with a yellow halo. More prevalent in early spring or in cool, we weather. Use disease free seed. Crop rotation, weed, do not over-water. Burn diseased plants

Spotted Wilt Virus – Plants stop growing, Bronze spots on leaves. Fruit is blotchy and ripens unevenly. Weed. Remove and destroy infected plants. Control aphids and thrips

Fusarium Wilt – Yellow leaves at base of plant, Stems show a brown discoloration if cut. Prevalent in warm weather, Plant disease resistant varieties, Practice crop rotation

Blossom drop – Low temperatures in spring or high temperatures in summer. Shade plants in hot weather. Protect from high winds

Sun Scald – light brown patches on fruit. Do not remove too many leaves. Shade plant.

Blotchy Ripening – parts of fruit yellow.orange. Too much heat, not enough potash. Too much water. Water moderately

Misshapen fruit – virus. Poor pollination due to temperatures being either too hot or too cold. Plant in late spring.

Magnesium deficiency – yellow between veins of the leaves

Rolling of older leaves – excessive de=leafing. Wide variation between night and day temperatures. Mulch to control soil temperature and moisture.

Pests

Aphids (Greenfly) – Sap suckers! Aphids attack the new growth on a plant. Try companion planting with basil to deter both Aphids and whitefly.  Ensure you water regularly in dry weather,

Create your own organic spray by soaking 2 cups of chopped tomato leaves in 2 cups of water overnight. Strain and add 2 more cups of water to strained liquid. Spray on plants, particularly on the undersides of leaves and growing tips.

Spider Mites – Sap suckers. Leaves will appear bronzed and may wither. A fine webbing is produced and may be seen on the underside of leaves.  Especially a problem in glasshouses

Tomato Fruit Worm – These caterpillars eat into both ripe and unripe fruit leaving small tunnels and holes. The moths of these caterpillars enjoy corn, so avoid planting corn to close to tomatoes when ever possible.

TPP (Tomato Potato Psyllid) – A relatively new and devastating bug. The psyllid secrets a toxic saliva that can severely damage a plant. Plants will show a slight discoloration of the top leaves along the ribbing and leaf edges followed by the entire plant top changing to yellowish-green. Due to the size of the psyllid standard bug netting is not adequate, however psyllid netting is available (it has a much finer weave).

Whitefly – Similar to aphids whitefly are sap suckers and do similar damage. When the plant is disturbed a cloud of white insects will be visible. They will show a preference for stressed plants, leaving healthy ones alone. More likely to attack when phosphorus of magnesium is deficient.  Eggs hatch about every 3 days so treatments need to be done every three days for at least two weeks to break the cycle.

Tomato Fruit Worm – Small caterpillar tunnels in fruit.

Companion Planting

Asparagus, Basil, Borage, Carrots, Celery, Chives, Dill, Marigold, Gooseberry, Grape Vine, Marjoram, Mints, Nasturtiums, Onions, Parsley, Parsnip

NEVER Apricot, Beets, Cabbages, Fennel, Rosemary