Growing tomatoes in a temperate climate often seems like a race against time. If you are battling a shorter outside growing season then you may often find that you have green tomatoes left on the vine as the first frost rapidly approaches. While tomatoes will ripen off the vine, those that mature on the plants will usually have the best flavour. Here are some tips to help you mature as many tomatoes on the vine as possible before time runs out:
Introduce Extra Protection
The first thing to think about is how you can extend the season and keep tomato plants productive and happy for as long as possible. You may wish to consider a polytunnel or greenhouse next year, to facilitate year round growing and eating. Even this year, however, you could consider providing extra protection for tomato plants in your garden. Consider placing row covers or horticultural fleece over your existing plants to protect them from the first, light frosts. This will give green tomatoes more time to ripen.
As the weather cools, remember to reduce the amount of water that you provide for your tomato plants. If it rains a lot where you live, again, covering your plants could help. Just remember to uncover them again on sunny days, as the sunlight is required to ripen up the fruit.
Prune Tomato Plants
Giving tomato plants a 'haircut' can also help to induce ripening. Cutting off the lower leaves and any dying or diseased leaves on each plant will free up energy that the plants can put into ripening the fruits. Another way to refocus the plants' energy is to remove all the flowers to concentrate on ripening up the fruits that have already formed. The flowers will likely not have time to set fruit that will mature before the first frosts, so their loss will not reduce your yield. Immature fruits may also be too small to grow to maturity late in the season, so these can also be removed to allow the energy to go into maturing the fully grown or almost fully grown tomatoes.
Place Ripening Bananas Beneath Your Plants
Bananas and other ripening fruit will give off a gas called ethylene. Ethylene speeds up the ripening process so placing a source of this gas below your tomato plants will help to produce a few more mature tomatoes before the season is over and done.
Give Tomato Plants a Shock
One final, and rather drastic measure that you can take to help green tomatoes to ripen is to give tomato plants a 'shock' by giving them a slight tug to shift and loosen their root systems. It may seem a little cruel but this will send a signal to your tomato plants that they should hurry up and produce viable seed to ensure their survival. This will tend to encourage them to put more energy into ripening existing fruit rather than putting on any new growth.