How to Grow Greenhouse Tomatoes

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HOW TO GROW GREENHOUSE TOMATOES - GROW BAGS

Possibly the commonest method of growing tomatoes in greenhouses is to use grow bags. These are simply plastic bags filled with a compost mixture. Cut two holes in the top and grow your tomatoes in the bags. This method certainly gets rounds the soil contamination problems because at the end of the season the grow bags are disposed of and new ones bought for the next season

Costs are on the low side; new grow bags cost relatively little and the cost of liquid fertilise is minimal. Given the amount of tomatoes produced using this method, it is also financially sensible, and the tomatoes produced are of course home grown and better tasting compared to shop bought tomatoes. Other main advantages and disadvantages are listed below.

One variant of growing tomatoes in grow bags is to puncture the lower part of the plastic container. If the grow bag is on soil the longer tap roots of tomatoes which search out water may well then grow into the soil below and find a good supply of water. In some of the examples we have seen, this is repeated year after year with little or no introduction of pest and disease into the soil below. In essence, this method then becomes a variant of ring culture (see below).

One word of warning though about the above. If the depth of the grow bag is small, some of the fibrous roots may find their way into the soil below and this has the distinct possibility of introducing pests and disease into the soil. Keep this in mind if your grow bag tomatoes show signs of disease.

HOW TO GROW GREENHOUSE TOMATOES - DIRECTLY IN THE SOIL

The key advantage of growing tomatoes directly in the soil is that you simply plant them without much preparation. The key disadvantage is that within a very short time pest and diseases will build up. The only solutions are to either remove the top soil annually and replace it with new sterile soil, or, to heat sterilise the soil each year.

The key good and bad points are summarised below:

Other than growing tomatoes directly in the soil for the first year of a greenhouse, we do not recommend this method. Pest and disease accumulations in the soil will quickly become unmanageable.

BOTTOMLESS POTS (RING CULTURE)

This is not complicated and many greenhouse gardeners use this method, or a variant of it, without realising. Large plastic pots have their base cut out, and they are then placed directly on the soil, grit or gravel. Click the picture on the left to see an an enlarged version. When the tomato plants are ready to be transplanted and all danger of frost is passed, the bottomless pots are filled with compost and the tomato plants are transplanted into them.

The theory behind ring culture of tomato plants in greenhouses is based on an understanding of their root system. Tomato plants have two types of roots: the roots near the surface search out primarily food and nutrients; the lower tap root searches out water. Click here for more information on tomato plant roots.

The standard method of greenhouse using bottomless pots (ring culture), tomatoes or other vegetables, is as follows:

The standard method above uses a 15cm / 6in layer of grit between the bottomless pot and the ground below the grit. The taproots will grow through the grit to reach the moisture in the soil below. Many gardeners have been using the above ring culture but without the layer of grit. The bottomless pot is simply placed directly on the soil. I know several greenhouse gardeners who have been doing this for many years with great results. It saves buying the grit, washing it each year and then storing it for next year. The choice is yours.

The advantages and disadvantages to bottomless pots (ring culture) are summarised in the table below:

HOW TO GROW GREENHOUSE TOMATOES - OTHER METHODS

The above three methods cover the most common methods of growing tomatoes but there are others. Hydroponics, grafted and disease resistant plants, straw bale culture
are nut a few. However, the the main ones in the main article above are probably the only ones worth considering for the amateur gardener.

Name: jim@GardenAction
E-mail: webmaster@gardenaction.co.uk
Date posted: November 19, 2011 - 04:34 am
Message: Indeed, all three are good. Look at the commercial varieties, like moneymaker.

Name: Kassang Sheyin
E-mail: Sheyinkassang@yahoo.com
Date posted: November 19, 2011 - 02:06 am
Message: Hi,i would like to know if i can use the three methods to produce tomatoes in a large scale.And what are tomatoe feeds? and what variety of tomatoes are the longest yeilding. thanks

Name: Mike Rogers
E-mail: Private
Date posted: December 15, 2010 - 01:41 pm
Message: What is the recommended spacing for tomato plants in a green house. I am considering 2 plants per bag spaced 12" apart and rows
48" centers. Do the plants require more space than this?

Thanks

Name: Eirian Rees
E-mail: Private
Date posted: September 21, 2010 - 08:05 am
Message: When growing tomatoes directly in the soil in a greenhouse could you please advice me do tomatoes self seed and grow smaller shoots and should we pick these out in order to give more space and strength for the main tomato plants? Thanks would like to solve an argument!