HOW TO CARE FOR
OUTDOOR TOMATOES

By David Marks
Tomato plants are not complicated to grow well but they do benefit from regular care. Their first need is for regular watering in dry conditions. Without that they suffer from a variety of problems.Correct and regular feeding is key for the fruit to form well. They need different nutrients at different stages of their growth.Finally, pruning is key for cordon type tomato plants. Removing and pruning away dyeing and low-growing foliage benefits both cordon and bush tomato plants.

WATERING TOMATOES

Tomatoes need more water compared to most vegetables and at the same time they do not cope well with irregular watering which can cause several problems ranging from split skin to blossom end rot. One key rule when watering tomatoes is to water the soil not the plants. Keep tomatoes leaves as dry as possible to help avoid fungal diseases. Tomatoes growing in open ground will need watering whenever the top soil dries out. In warm weather they may need watering every two days and a good drench is the best solution. Tomatoes grown in grow bags require more frequent watering. Don’t let the compost dry out in a grow bag, it is very difficult to rehydrate it.

For all the tomato varieties which we have fully reviewed, click the drop down box below, select a variety and then click the More Information Button.

FEEDING TOMATOES

When tomato plants are initially planted in grow bags they will not require feeding for another three weeks because there are sufficient nutrients already in the compost. After that feed the tomato plants with a liquid tomato fertiliser at the rate suggested on the packaging up until early September. For tomato plants growing in open soil the feeding regime depends on the nutrients in the soil. With soils that have reasonable levels of nutrients in them a couple of applications of blood, fish and bone throughout the season is sufficient. For less nutrient rich soils an additional fortnightly feed with liquid tomato fertiliser will help lots of fruit form and mature well. Do this until early September.

In early September it’s best for for all tomato plants to change the feed to a balanced liquid fertiliser.

HOW TO GROW THE BEST TASTING TOMATOES?

This section is NOT about what tomato variety to grow it’s all about how to get the best
tasting tomato whichever variety you grow. Currently, science has not provided a complete answer to this question but there are some guidelines you can follow which will definitely improve the taste. Select those which you can easily provide.

MORE SUN EQUALS MORE TASTE

This does seem to be something about which the experts agree. Your number one priority when choosing a site for tomatoes is full sun. Sun provides the key energy source for growing new and large leaves and these increase not only the depth of flavour but also minor but very important flavour compounds which work their way into the tomatoes themselves.

LESS WATER EQUALS MORE TASTE

This is also something on which the experts agree. In independent tastings, tomato plants which had an excess of water available at the roots tasted blander compared to those which had less water. This is the key reason why supermarket tomatoes have less taste compared to home grown ones.

There is a dilemma however with this availability of water; too little water and your tomato plants will suffer or even die. The key to flavour enhancement is to provide them with just a little less water than they really need, but only just a little! Every site, growing method and variety requires a different amount of water so I can’t simply say your tomatoes need x litres a day to provide the maximum taste, it’s all a matter of experience.

The need to water regularly, albeit slightly less, is not reduced either. Irregular watering can cause blossom end rot and that renders them unusable. So regular watering but just a little less is one of the key methods of increasing tomato flavour.

When taste tests have been conducted in a scientific matter it appears that the effect of overwatering is noticeable in only a few hours. Tomato plants overwatered in the evening resulted in blander tomatoes the next day.

THE COMPOST / SOIL REALLY COUNTS

This is just as important as the above two sections. Most supermarket tomato plants are grown in near hydroponic conditions with very little contact with compost or real soil. If your compost contains basically a mixture of nitrogen, phosphorus and potassium / potash as provided by most garden plant feeds it is seriously lacking in a huge variety of micro-nutrients. It is these micro-nutrients which provide the majority of flavour in tomatoes.

Natural soil in good condition as found in your garden almost always supplies a good balance of these micro-nutrients and this is the best medium in which to grow your tomatoes if flavour is your key criteria. For the majority of people however, grow bags and containers are the most reliable method for growing tomatoes, if not only for the sake of convenience.

In practical terms, the best way to grow tomatoes for flavour is in open ground which has been dug to a fine tilth and with lots of well-rotted material incorporated into it. If space and / or convenience is at a premium and you want to grow your tomatoes in grow bags or containers then cut out a 20cm / 8in circle in the plastic at the base of the base of the grow bag. Dig the soil below where you intend to place the grow bag or bottomless container to a depth of 30cm / 1ft.

This practice will allow the roots of the tomato plant to grow to the bottom of the grow bag / bottomless container and into the soil below where there will be a wide range of micro-nutrients which will increase the flavour.

ARE TOMATO PLANTS SELF FERTILE?

All tomato plants are fully self-fertile which means even a single tomato plant, grown entirely on its own, will quite happily fertilise itself. Having said that though, some gardeners are strange folk and often believe that shaking a tomato plant very gently or tapping the support canes / strings when it is in flower will help the pollination process. Personally, I think the wind causes more than enough movement in the plants but no scientific tests have been conducted to prove or disprove the theory either way.

PRUNING TOMATOES

Pruning tomato plants can be a reasonably therapeutic task if you do it regularly, slightly more traumatic if you leave it August when the plants are bound to have become congested and the structure of the stems hidden by foliage. We have written a page dedicated to the subject of pruning tomato plants and it can be found here.

HARVESTING TOMATOES

There’s probably masses of information on the internet and in books on how best to harvest tomatoes but in reality the best way to harvest them is to wait until they look ripe, harvest and try them, eat them and if they are not quite ripe leave them another week.At the end of the season though, late September to early October you may well find that you have green tomatoes which simply will not ripen on the vine. Do not give up hope, harvest them before the frost gets to them and place them on a warm windowsill. In our experience several varieties ripen well under these conditions, Alicante and Gardener’s Delight are two we know.

MORE INFORMATION

We give below an article entitled “The Development of Tomato Root System in Relation to the Carbohydrate Status of the Whole Plant” published in 1997. It can be found by clicking here. This article is hard work to read and you will probably end up up realising how little you really know about growing tomatoes. However it will certainly cause you to question your current cultural methods and inspire experimentation.

COMMENTS / QUESTIONS LEFT BY OUR READERS

Sometimes our readers ask specific questions which are not covered in the main article above. Our
Outdoor Tomatoes comment / question and answer page
lists their comments, questions and answers. At the end of that page there is also a form for you to submit any new question or comment you have.

MORE PAGES ABOUT GROWING OUTDOOR TOMATOES:

Growing Outdoor Tomatoes