Skip to content

A Guide To Growing Your Own Tomatoes

Your garden is your space to do with it as you see fit. You might be bursting with ideas and are keen to get started or you might feel a little unsure of where to begin.  If you fancy starting a garden project but aren’t certain what you should try first, why not turn your attention to tomato growing? Tomatoes are relatively easy to grow and are a rewarding addition to any garden. 

Growing Tomatoes in Grow Bags

You can start growing tomatoes in grow bags within the greenhouse from late February to mid March. 

Grow bags are an effective way to grow plants as the bags encourage healthy root growth. You can easily grow tomatoes in grow bags with our simple guide.

Tomato Plants in Grow Bags

Start off the seeds in pots, in a warm indoor light area, at the end of March/early April, prior to transplanting into grow bags.  When using grow bags, it is found that tomatoes do better and have stronger root growth when the bags are cut into two equal size portions (see photo). Once this has been done, loosen the soil in each bag to allow the roots to work into the soil.  

Then, cut two slits at the base of each pot shaped bag to allow soaking up of water and feed.  The bags should then be placed in a grow bag tray in the greenhouse for ease of watering (see photo ).  

Transfer the plants from the pots to the growbags, then add a cane to each growbag, approx 5’ or the height of your greenhouse.  This will allow you to give the plant support as it grows.  Tie at 6” intervals.


Caring For Tomatoes in Grow Bags

Ensure that the water in the grow bag tray is topped up every day.  This will need topping up twice a day when the weather is very hot. 

As the tomato plants grow, you will see side shoots appear at leaf joints.  These need to be pinched out when they are approx 3 cm (1”) long. Pinching out is a method of pruning tomatoes that helps plants to focus on growing stronger. 

When the plants reach approx 1.2 m (4’) tall, start to remove yellowing leaves below the fruit truss using a sharp knife.

When watering, add a liquid tomato feed, such as Tomorite, once every two weeks.

Once your plants have reached the top of your greenhouse, or have seven trusses, pinch out the growing tip at the top.


Growing Tomatoes In Soil 

If you would prefer to grow tomatoes outdoors, you should first sow tomato seeds indoors. You can start to do this in late March and early April. Sow the seeds in small containers and place them in an area that has a lot of sunlight, such as a windowsill. 

When the seeds begin to flower, that is the time to move them outside and plant them into the soil. 

Tomatoes should be planted in the soil with gaps of 45cm (18’’) in a sunny area so that they can make the most of the sunshine. When planting, leave a slight imprint in the soil as this helps to keep moisture around the roots. 

To encourage healthy growth, we recommend using Tomorite, a liquid plant feed  containing seaweed that supplies tomatoes with the necessary nutrients required for higher yields and juicy flavour. 


Common Problems That Affect Tomato Plants And How To Deal With Them

Ensure that you water tomatoes regularly as failing to do so will result in a condition called blossom end rot. This will be shown through the ends of the tomatoes producing dark blotches.  Watering the tomato plants encourages calcium production, resulting in strong and healthy tomatoes. 

Be aware of the condition of the leaves on tomato plants that are growing in the greenhouse. Greenhouse grown tomatoes can suffer from leaf mould, as shown by yellow blotches appearing on the upper surfaces of the leaves, while mould grows underneath. 

A way to combat this problem is to provide sufficient ventilation by opening the greenhouse windows to improve air circulation. 

One last problem that tomatoes encounter is cracking or splitting. This can be caused by differing temperatures and water supply. Split fruit left on a plant can often be infected with fungus. As this is a problem caused by environmental factors, there is no point in using pesticides to fix it. 

Tackle this problem by feeding the tomatoes with a feed such as Tomorite to promote fruit development and boost soil fertility. Watering often will also help soil to lock in moisture. 


Harvesting Tomatoes

You should start to harvest tomatoes from July onwards, depending on how each individual tomato has grown. Pick the tomatoes when they are ripe and full coloured. 

At the end of the growing season, if some fruits haven’t ripened, lift them out and place them indoors in a dark and warm space to encourage ripening. 


Growing tomatoes is a simple way to introduce vegetables to your garden and to reap the rewards once harvesting begins. Hopefully, you will now feel more confident to grow more vegetables and will become an expert in no time!