Articles and Tips for
Growing Tomatoes
Click on these links to view informative tomato articles
Articles are regularly added, so check back often!

7 healthy reasons to eat tomatoes

What type of tomatoes to grow

Valuable watering tips

Fertilising for the home gardener

Understanding your soil

Fungicides

Manure

Manure tea

Pruning your plants

Death of seedlings - "Damping Off"

7 Healthy Reasons to Eat Tomatoes

Tomatoes are a good source of vitamin C and potassium. They also pack plenty of the phytochemicals that provide disease prevention benefits. Tomatoes are high in lycopene (a powerful antioxidant) and phenolic compounds. In our diet, 95% of lycopene intake comes from tomatoes and tomato products. It is also found in watermelon, pink grapefruit, papaya and rosehip.

tomato paste is very good for you

Lycopene is better absorbed by the body when cooked with oil.

Lycopene is the carotenoid that makes tomatoes red. It appears that lycopene can reduce the risk of certain cancers, the eye disorder age-related macular degeneration, atherosclerosis and sun damage to the skin.

Men who eat two or more servings of tomato products average a 35 percent reduction in prostate cancer risk.

Lycopene helps women guard against cervical intra-epithelial neoplasia, (CIN), tumorous tissue growth in the cervix according to research from the University of Illinois at Chicago. Lycopene is a powerful inhibitor of the growth of breast, endometrium (inner lining of the uterus) and lung cancer cells.

Lycopene is better absorbed by the body when it is cooked with some oil. The cooking helps to break down the cell walls of the tomato releasing the lycopene and the oil helps increase its absorption. Japanese scientists found that mixing tomato juice into the drinking water of mice completely prevented them suffering emphysema triggered by tobacco smoke.

Tomatoes also contain Lutein. Lutein is found in the retina of our eyes so it needed for healthy vision. Lutein also appears to lower the risk of cataracts and macular degeneration. Lutein may also help to prevent or slow down the thickening of arteries that is called atherosclerosis. Atherosclerosis is a major risk for cardiovascular disease.

Tomato products are beneficial in aggressive cancers that have also spread to other parts of the body.

More detailed information provided in How to Grow Juicy Tasty Tomatoes.

What type of tomatoes to grow

Choosing the variety is important. You need to decide what characteristics are the most important to you, as well as the climate and disease susceptibility in your area. No one variety will perform best across all planting seasons and regions. Issues such as fruit firmness, size, shape, flavour and plant growing habits need to be considered.

You also need to decide whether you want a ‘jointed’ tomato variety or not. In other words, do you want a tomato variety that retains its stalk when picked or one that comes away cleanly from its stalk when picked. Many commercial organic and gourmet tomato growers choose ‘jointed’ tomato varieties because the tomato with its stalk attached looks attractive to the buyer. However, most home gardeners and non-organic commercial growers choose ‘jointless’ varieties.

brandywine tomato

cherry tomatoes

Indeterminate varieties such as the Brandywine (top) and cherry tomato produce tasty fruit over
a long period

The next choice is whether you want a ‘determinate’ or ‘indeterminate’ variety. A determinate variety grows to a bush about 1 metre (3 feet) high. At this stage it stops growing and sets a concentrated crop of tomatoes which can be picked over a few weeks.

Indeterminate varieties keep growing and can reach a height of up to 5 metres (15 or more feet) when fully mature. The fruit from these can be picked over a period of 12 to 20 weeks. These varieties are frequently used by greenhouse producers. Many cherry tomato varieties are indeterminate.

There are also ‘semi-determinate’ varieties which grow to about 1.5 – 2 metres (4 – 6 ft) and set fruit over a longer period than determinate varieties. These are the best suited to home gardens. They generally require staking and the tomatoes are harvested over 2 – 6 weeks.

Detailed information on hot climate and cold climate varieties as well as 100 popular varieties provided in How to Grow Juicy Tasty Tomatoes.

Valuable watering tips

Water thoroughly to encourage the tomato roots to seek water and nutrients deep in the soil. With an extensive, deep root system, the plants will hold up better during dry spells. When watering, soak the soil to a depth of at least 15-20 cm (6-8 inches).

 

tomato cracking

Incorrect watering is the main
cause of cracking like this

 

  • Water only when your plants need it. Tomatoes like moisture, but overwatering is harmful. You not only waste water, but soggy soil will prevent the roots from getting the air they need. If your plants look a little wilted on a hot, summer afternoon, that’s usually normal. They’ll perk up overnight. If plants are wilted in the morning, don’t wait -- water them! (However remember that certain diseases can also cause wilting.)

  • A thorough soaking every four to five days on light, sandy soils and every seven to ten days on heavy soils is a good general guide for irrigating if you don’t get enough rain.

  • Water early in the day to cut down on evaporation losses and also to give your plants plenty of time to dry out. Wet foliage overnight may help trigger some diseases.

  • With furrow irrigation, drip irrigation or soaker hoses, which all deliver water right at the soil surface and not on the leaves, you can water almost anytime. Try to avoid watering at midday though, because that’s when evaporation losses are highest.

  • Trickle irrigation is the most easily controlled method of irrigation. The equipment is expensive, but is long lasting and saves growers time. It can also be scheduled to deliver constant amounts of water, which can help reduce the incidence of fruit cracking.

  • Use mulch to reduce evaporation, improve water spread and uptake by the plants and reduce disease caused by rain and water splash

Full details on calculating exact watering requirements (how much, how often for size of plot) plus how to set up a simple irrigation system are provided in How to Grow Juicy Tasty Tomatoes.

Fertilising for the Home Gardener

Starter Fertiliser
All plants enjoy substantial amounts of organic matter – manure or compost in the soil. Organic matter holds nutrients in the soil so that they are not lost through leaching. It increases the amount of water your soil can hold as well as microbial activity in the soil, encouraging earthworms and creating a wonderful healthy soil system that produces nice sweet tomatoes.

Compost in the soil takes time to break down and release its nutrients– often up to 2 – 3 months. This means that if you want to use compost alone, it should be dug into the soil at least a month before you wish to plant your tomatoes.

It often helps to add a bit of fertiliser (even if you have used compost) at 5cm (2 inches) below and 5cm (2 inches) to the side of where you plant your seedling. If you put fertiliser directly in contact with the roots you will burn them and your tomato seedling may die or its growth be retarded.

tomato granular fertilizer

 

tomato liquid fertilizer

It is important that granular and liquid fertilizers are applied properly to avoid burning or even killing your plants


Understanding Fertiliser Units
All fertilizers are generally described by their analysis. This usually consists of 3 figures that respectively label the percentage of Nitrogen (N), Phosphorus (P) and Potassium (K) in a product.

The sequence of N, P and K never changes. However in the USA these units are designated as N - P2O5 – K2O whilst in other countries (such as Australia) the units are N-P-K.

P2O5 means phosphate in the oxide form, as opposed to phosphorus (used in Australia) and K2O is the oxide form of potassium whilst in Australia only K or potassium is used.

You will find full details about fertiliser use (what to put on, when to put it on, how much to put on and how to apply it) in How to Grow Juicy Tasty Tomatoes.  The fertilising chapter also contains valuable advice and photos on recognising and correcting nutrient deficiencies.

Understanding your soil

Tomatoes will grow in a wide variety of soil types and across a wide range of pHs although they prefer a pH between 5.5 – 6.8.In order to understand your soil type it is essential that you have an understanding of what pH is and how it may affect the nutrition of your tomatoes.

The term pH defines whether your soil, is acid or alkaline. The pH scale runs from 0 – 14 with 7 being neutral. Numbers below 7 indicate acidity and above 7 alkaline. Most soils have a pH in the range 4.5 to 8.5. Tomatoes enjoy a slightly acid soil usually with a pH around 6.5.

The availability (uptake of nutrients from the soil by the plant) of nutrients is affected by soil pH. This is amply demonstrated by the chart below.

This shows that most nutrients have greater availability at pHs around 5.5 – 6. pHs can be adjusted : lime will make the soil more alkaline and whilst making the soil more acid is more difficult, usually sulfate-based fertilizers (eg sulphate of ammonia) and acidic organic material will help.

Testing soil pH can be done simply by mixing soil and water and testing it using a pH meter, testing kit or litmus paper.

Fungicides

Every country has its own list of government registered fungicides for different crops. Suppliers of these chemicals have to prove that they work, and usually that they will not cause undue damage to the grower and the environment.

The list of registered fungicides for home gardeners is quite small and in the case of tomatoes revolves around the use of two in particular. The “active” ingredient of one is mancozeb and the other is copper. Although every country and reseller usually has a different commercial or selling name for it’s fungicides, in most cases the “active” chemical is the same.

Mancozeb is the active of products often used for leaf spotting diseases.

root rot

You can control root rot
with a fungicide

Copper-based chemicals can also be used for leaf spotting diseases, but are best for bacterial diseases which mancozeb will not control. These chemicals should be applied prior to the plant getting the diseases as they will not control diseases that have already started on the plant.

Fungicides are best applied prior to rain, and then following rain before the appearance of disease. Fungicides will not control bacterial wilt-type diseases as well as some fungal wilts. However there are fungicides available for Phytophthora Root Rots.

Viral diseases are usually controlled by controlling the pest and practising good hygiene.

Manure

Manure remains the best of all fertilisers, with compost running a close second. Whilst the proportion of the three major nutrients that manure contains is rather low, and dollar for dollar artificial fertilisers do give more weight of nitrogen, phosphorus and potassium; manure rots down to make humus to benefit the soil and its micro-life.

manure

Any type of manure should be heaped for six weeks or so before using

When you buy manure, it is likely to be pretty fresh – and far too strong and ‘hot’ to use. You will need to leave it in a heap for six weeks or so; covered with a plastic sheet to keep the rain from leaching the nitrogen out. This also allows you to assess whether the manure contains a lot of weed seeds as they will germinate in this time. Those deep in the heap will probably be killed by the heat of fermentation and any that come up on the surface can be put on the compost heap. Or if there is room in the bin you can simply dump the manure on the compost heap.

Discover which type of manure is the best -cow, horse, sheep or poultry in How to Grow Juicy Tasty Tomatoes.

Manure Tea

If you feel that your tomato plants would benefit from a quick boost, then manure tea is a great way to encourage them.

manure tea
Manure tea provides a
quick boost

Simply put a couple of shovelfuls of manure into a Hessian bag and then steep it like an outsize teabag in a garbage bin full of water for a day or two until the water is the colour of weak tea. Don’t use it on dry soil, however as it may be too concentrated.

Keep the lid on the garbage bin, the brew smells and will attract flies. It will keep for a week or so, or you can pour any leftovers on the compost heap, along with the contents of the used ‘teabag.

Pruning your plants

With tomatoes it is important to maximise the efficiency of photosynthesis and limit the amount of disease. To do this the plant needs lots of light and airflow around it.

If a plant is properly pruned and supported, nearly every leaf will have access to the sun. Most of the nutrients and sugars produced are directed towards the newly developing fruit as well as the growing tip. Fruit production does not stop (unless the plant is affected by weather or is lacking in water).

tomato pruning

Pinching out side shoots promotes stronger growth and improves plant health

As more and more growing tips are produced, via branches, so the plants resources become more divided. This results in ever decreasing fruit size in indeterminate tomato varieties. Determinate varieties are self limiting mainly because of their shorter growing season and more defined fruit setting period.

Those varieties that mature in less than 70 days normally do not require pruning. However, late-season indeterminate varieties often need some of their side shoots or their tops trimmed to prevent them becoming too bushy or tall. With both determinate and indeterminate varieties, it is best to limit the number of trusses to six or seven in order to get good quality fruit.

Pruning also increases plant health. The leaves of a pruned and supported plant dry off faster so that fungal and bacterial diseases have less opportunity to spread.

Essentially, staked and pruned plants have fewer problems with fruit rots and leaf spots because their leaves stay drier, and the plant has good airflow around it. Leaves and fruit should never be allowed to sit on the soil.

Discover the two most popular methods of pruning in How to Grow Juicy Tasty Tomatoes.


Damping Off

The term ‘damping off’ refers to the death of young seedlings, either after emergence or after transplanting. The stem of the seedling turns brown or black at soil level and withers causing death of the plant. This is commonly caused by any one of three diseases – Pythium, Rhizoctonia or Phytophthora.

Damping Off

"Damping Off" - a problem with
seedlings, can be controlled

Damping Off is a problem in cold, wet soils or in cool, damp weather. It can also be caused by crowding of seedlings, over watering, lack of air circulation or contaminated pots, soil or water.

Discover how to control Damping Off in How to Grow Juicy Tasty Tomatoes.