Growing your own tomatoes is one of the most rewarding fruit to grow. Tomatoes are easy to grow but not always easy. Our tips will help you grow tomatoes even if it’s your first attempt.
Tomatoes grow in two ways bush (horticulturally called Indeterminate) and cordon (determinate). Popular Bush tomatoes include some outdoor varieties such as Red Alert and the most popular varieties of Tumbler tomatoes which are ideal for hanging baskets.
Cordon variety are the type of tomato grown with supports such as canes or string. It’s important to remove the side shoots on cordon varieties for the most fruit. Bush varieties don’t need the side shoots removed.
Tomatoes are tropical plants
It’s worth remembering this when you are in your garden in early to mid spring and you shiver and put extra clothing on. Even if the day time temperatures are warm the night temperatures are often too low for tomatoes. They are killed by frost but they are also stunted by the cold and either never flourish of take a long time to recover. Tomatoes originate from central America.
Tomatoes from seed
Tomatoes are best sown later than the seed packets indicate. In the Sheffield region & the north of the UK sow at the end of the suggested sowing period on the reverse of the packet. If you sow too early inside your house there will come a point when the plants are getting too big for your windowsill. If it’s cold at night you plants will suffer. If you so as late as possible then the chances of taking your plants outside & growing them successfully is improved.
Tomatoes prefer a greenhouse but..
UK summers are notoriously fickle. Walk in greenhouses can moderate the day and night temperatures and protect from the wind. Plastic small ‘greenhouses’ don’t protect as well as you might hope during cold nights in early to mid spring. Bigger plastic tomato houses are beneficial when the nights are warmer as they protect the plants from wind & also extend the season for ripening.
You must ventilate these structures on hot days. Shading from the full sun in the middle of summer may be needed.
Humidity is ideal for cucumbers but not tomatoes. If growing both grow cucumbers at the opposite end to the door. Open up the greenhouse on warm days and even consider removing a lower pain of glass or polycarbonate to allow the heat to draw in fresh air. Close the doors at night. Open the roof vents though to reduce condensation & disease.
Growing without a greenhouse.
It’s easier to buy a few plants when the weather is suitable than to grow from seed and sow too early. Most families only need two to three tomato plants. Seed raised tomatoes may take some months to ripen however grafted tomatoes fruit and ripen earlier and tolerate out summers outdoors better.
Seed raised or grafted tomatoes?
For many years gardeners have successfully grown tomatoes at home that are grown from seed. Until recently for most of us that was the only type of tomato plants available albeit with newer stronger & prolific varietes coming along.
Now a very old technique has been reawakened that has changed home growing forever. Grafted tomatoes are here and the results are incredible. Grafted tomatoes are tomato varieties grafted onto strong vigorous rootstocks to give great performance.
Our grafted tomatoes are grown by Suttons Seeds in their greenhouses near Hull. Each variety is grafted to the vigorous rootstock by hand. This make them more expensive that seed raised tomatoes but the produce 3 times more fruit.
Also these varieties ripen earlier even outside. Customers who have grown these over the last few years are amazed to have ripe fruit in July, when seed raised varieties are green until August.
Feeding tomatoes is vital. Using a tomato feed such as Tomorite is recommended.
Tomorite is a high potash food. High Potash feeds promate fruit & flowers but Tomorite is also high in Nitrogen to balance out the very high Potash that tomato feeds need. Without this amount of nitrogen the leaves turn dark green & curl up. When this happens the plants don’t perform to their full potential. Always follow the feeding instructions on the bottle.
General feeds are better than no feed at all but tomato feed like Tomorite make a vast difference.
Giving a good supply of water is obviously very important but even and regular watering is vital. Tomatoes hate water logging & also hate to dry out. This can be a problem if you are away from home all day. There are a variety of watering products including Hozelock’s drip system but the easiest to set up and use is Hozelock’s growbag watering tray (see below). this has a 15 litre reservoir for water & it delivers the water supply through capillary action as the roots draw on the water in the compost. It easy for others to fill the reservoir if and when you are away, if they forget one day your tomatoes still get watered ‘all on their own’.
Drainage: on the side of a grow bag or tomatoe planter you will see a fold line made before the bag was filled with compost. Once filled this line appears about half way up the side of the bag. With a sharp knife cut 4 x 1″ slits in the plastic. This way if they bag is over watered excess can escape but leaving some in the newly formed reservoir below the line. This will help prevent water logging and overwatering.
Growing cordons with supports
Growing cordon tomatoes means you will need a way to stop them from falling over. The stems tied to canes with raffia or soft string works well but canes wont stay upright in grow bags. Using a grow bag cane support is the easiest way to keep the canes upright. Don’t push the canes through the bottom of your grow bag. It will drain the water away.
One frame at a time can also be used with some pots.
Another way is to use some strong twine, polypropylene is best as it’s waterproof, looped under the grow bag where each plant will be growing. Tie the loop up around the gow bag and pull a length up from the bag to the frame of a greenhouse or a rail above. as the tomatoes grow gently twist the twine around the stem of the tomato.
It’s worth knowing that the Hozelock Grow bag waterer includes can supports built tinto the base. These puncture the bag but in this case it doesn’t matter.
Tomatoes ripen with the variety, the season, and with sunshine. The sun plays a big part in ripening especially late in the season. Grafted tomatoes have been proved repeatedly over the last few summers that they ripen weeks before seed raised tomatoes. Tomato feeds rather than general feeds aid ripening too.
Later in the season remove any leaves that are shading your tomato trusses. Sunshine helps them ripen.
At the end of the season green tomatoes can be ripened in the dark with a banana along side them. Bananas give of the gas Ethylene which aids ripening. Or place them in a tray on sunny windowsill or on the parcel shelf of your car but not if you have tinted windows. You need the sun and warmth.
Pests, diseases and problems
White fly & Aphids
Often confused but white fly fly off in clouds when you touch the plant & the ‘white flies’ you see with aphids are actually empty skins. Look more closely and you will see small green insect on the stems & leaves.
Treatment : find an insecticide that lists both such as Resolva Bug Killer or a suffactant treatment such as Ecoffective Bug and Mildew control.
Blossom end rot
This shows its self as black circular patches on the ‘blossom end’ of the tomato. It’s not a disease but a condition associated with calcium deficiency and uneven or poor watering. The poor or uneven watering prevents calcium reaching the end of the fruit. Normally there is sufficient calcium in compost to provide the required amount and tomato feed also includes extra. Watch your watering. Using a grow bag watering tray will help.
Tomato blight is also the same disease as potato blight , infamous for the Irish Potato famine. It’s returned to gardens in the last 20 years probably due to less sulphur in the atmosphere (less coal fires) and the wetter summers.
Treatment: there aren’t any fungicides for fruit or vegetables for amateurs to use in the UK, however ‘suffactants’ will protect your tomatoes (& potatoes) from blight. They work by seperating disease spores from the leaf. You must apply before you see the blight. Think of it’s use as a form of insurance. Tomaotes grown in a greenhouse are less prone to infection as the spores are carried in rain.
You may get this along or after blossom end rot if you haven’t watered evenly or properly. Split skins on all fruit is due to extra water after the skin has started to set at ripening time. If you water evenly and in response to changing weather conditions you should avoid splitting.
This is a varietal issue. Some varieties just get green back, the green harder area on the top of a tomato. If you don’t like it change varieties next year. We believe that every year you should try a plant of one new variety to see how it perfomers against your ususal choose.
Purple / dark green curled leaves
When this happens it’s usually an indication that you’ve been overfeeding. Overfeeding can reduce growth and crop.
Treatment : don’t feed for two weeks and water with plain water.
Green curled leaves
This may be a characteristic of the variety (have you tried a new one this year?), but is often casued by very hot weaher and bright sushine.
Treatment : shade your greenhouse.
Yellowing leaves all over the plant (and spindly growth) probably means you aren’t feeding or aren’t feeding enough. Use tomato food it’s the best for tomatoes. Yellow leaves later in the season and low on the plant is the plant moving food to the fruiting & growing area of the plant.
Treatment : feed properly. You can remove these leaves.