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How to grow tomatoes in a growing bag

You will need

  • 2 - 3 tomato plants
  • 60 or 75 litre bag of multi-purpose compost
  • Knife or scissors
  • Hand fork
  • Trowel
Do it: June (or May in a greenhouse)
At its best: harvest from July to September
Takes just: 30 minutes


Greenhouse tomatoes are often planted in grow bags, but outdoor crops can also be grown in this way too. A good alternative to a specialist grow bag is to try planting in a 60 or 75 litre sack of multi-purpose compost. This will provide your plants with a larger rooting area and stop them drying out in hot weather, which is better for the plants and means less watering for you.

How to do it

Young tomato plants in tray of water

1Soak pots of young tomato plants in a tray of water for an hour to ensure the compost is fully moistened. This will help reduce root damage during transplanting.

Cutting slot in bag for planting into

2Lay bag of compost flat in a sunny position in the garden, on a balcony or in the greenhouse. Shake compost inside the bag to create an even, pillow shape. Cut a slot out of the bag to expose the compost for planting them into.

Loosening the compost in bag using a hand fork

3Loosen the compost in the bag with a hand fork. Push some of the compost into the corners of the bag so that it maintains a good shape.

Knocking young tomato plant from its pot

4Carefully knock the tomato plants from their pots. Allow two plants for a 60 litre bag of compost,or three plants for a 75 litre bag.

Planting tomato plant with trowel

5Make a hole in the compost with a trowel and place the young tomato plant in it. Set the plant a little deeper than it was growing in the pot because tomato plants are able to produce roots from the stem, meaning they'll take up more water and nutrients. Water in well.

6Improve the effectiveness of your watering by burying a small flower pot in the compost alongside each tomato plant. Filling the pot when you water means water is directed to the roots of the plant and doesn't run off the surface of the compost.

Adam's tip

Start feeding your tomato plants with a high potash liquid fertiliser as soon as the first truss of flowers appears.

Discuss this project

Talkback: How to grow tomatoes in a growing bag
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crystal2010 24/11/2011 at 15:27

excellent ..would like your advice due to getting tomato blight last year for the first time in my greenhouse Im not sure how to proceed this year ..I mormally grow them in the soil should I use a grow bag or dig out some soil and replace it with new what do you advice? look forward to hearing from you margaret stead

jollyoldgran 24/11/2011 at 15:27

I planted the seeds that I got free with your magazine 27 seeds 26 really robust plants I put three in a grow bag in my conservetory yesterday I intend to try three more in a growbag outside and another lot in the ground, so that means I still have 17 plants to find a loving home soon as the weather improves I'll set to work

annejn 24/11/2011 at 15:27

What about growing in the garden? Bob Flowerdew's books have ggod advice on making a plastic tent for them...

tony2 24/11/2011 at 15:27

I grew some toms last year but did not have much success but after reading up on the site I've got 14 beautiful seedlings of three types all from seed from GWM and hopefully will have some lovely toms this year.

jonjack 24/11/2011 at 15:28

I recently tried growing tomatoes in one of those upside down tomato garden planters and I was really pleased with the results.

I have written a post about it on my blog as well as a how to for making your own upside tomato planter.

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