Most of us find that we have lots of green tomatoes in September. This is because when the temperature drops, ripening slows down considerably. If you are growing outdoors or in an unheated polytunnel or greenhouse the tomatoes will need to be harvested before the first frosts. Here are some top tips for ripening tomatoes.
Before the first frosts take steps to hasten ripening while the tomatoes are still on the plant.
1) Cover your tomato plants with a polythene ripening cover with air vents.
2) If you are growing on cordon (vine) varieties remove the supports and lay the stems on the ground and cover them with cloches.
3) Remove the leaves around the green tomatoes to expose the fruit to the sun
Tomatoes won’t survive a frost, so if a frost is forecast and you are growing outdoors you need to either bring the plant indoors or harvest the tomatoes green and ripen them off the vine.
If a frost is forecast you can pull up the whole plant and hang it upside down in a frost-free, cool darkish place like a cellar or garage. Many people say that this method gives the best flavour, which makes sense because the tomatoes are still ripening on the vine, although more slowly than when they were in the greenhouse or garden. Make sure that some roots are still attached. Shake off as much soil as you can and hang it upright. Avoid direct sunlight or total darkness; otherwise your tomatoes will die!
Bananas are our favourite method of ripening green tomatoes. Put 5 to 10 tomatoes in a brown paper bag with a banana. You can ripen more tomatoes if you line a cardboard box with dry newspaper and place the green tomatoes in a single layer with a little space between each. Cover every day or two, removing anything suspect. This works because bananas give of ethylene which is a gas that speeds up ripening. Apples give off the same gas.
Pick green tomatoes that have a tinge of colour at the blossom end and feel a little softer than the solid young fruits. To check whether your green tomatoes are mature, cut one in half. If it is yellowish inside and has a jelly-like or sticky tissue around the seeds making it difficult to cut the seeds, it is mature enough to ripen, so pick the ones that look similar to that one. Clean the tomatoes removing vines, twigs, stems, leaves and anything that might rub on the other tomatoes and cause damage during the ripening process. Take care not to bruise or squash the tomatoes and don’t pile them up!