Monty Don's fail-safe trick will ripen harvested green tomatoes fast – it's perfect for the last of the fall harvest

It’s a frustrating moment for any gardener: summer has ended, the leaves are turning, and your tomato vines are still heavy with stubborn green fruits. But all is not lost. Celebrity gardener and Gardeners’ World presenter Monty Don has a simple, one-ingredient hack to rescue your late-season harvest: a banana.

In his regular blog, Monty explained the challenge gardeners faced when growing tomatoes this past summer. Tomatoes ripen best when temperatures stay between 79 and 86°F (26–30°C), but this year, many regions experienced intense heat that stalled the ripening process, leaving countless fruits unripe.

As cooler early-fall temperatures arrive, natural ripening slows, and many green tomatoes seem destined for the compost heap. But Monty Don shows that even at this stage, harvesting tomatoes can still be successful – with a banana as the secret ingredient. It’s a tip every gardener should include in their fall gardening checklist to save their late-season tomato harvest.

How to use Monty Don’s tip to ripen green bananas

Monty Don's method is remarkably simple and effective. 'If you pick them,' he writes, 'either individually or on the vine, then put them in a drawer with a banana, they will ripen and turn red.'

The magic behind his method isn't magic at all – it’s science. Bananas, especially as they ripen, release large amounts of ethylene, a naturally occurring plant hormone. This gas acts as a powerful signal, triggering the ripening process in other fruits around it. By placing your green tomatoes in an enclosed space with a banana, you are creating a concentrated ethylene environment that forces them to ripen quickly.

As Drew Swainston, a former professional gardener and gardens editor, explains, 'It's common for growers to place unripe tomatoes into a paper bag with a banana; however, the same effect can be achieved by placing a banana among a bowl of tomatoes or putting the banana and tomatoes together in a sealed glass or plastic jar.' The key is to trap the gas so it can work its magic.

Whether you place your harvested green tomatoes in these brown paper bags from Amazon or glass mason jars with airtight lids, also from Amazon, adding a banana will help them ripen perfectly for you to enjoy

What about tomatoes still on the vine?

Monty Don's trick is best used when temperatures have dropped and on-the-vine ripening is no longer a viable option. However, before it gets too cold, there are a few things you can do to encourage ripening while the tomatoes are still on the plant:

Remove Leaves: Strip away some of the lower leaves to ensure sunlight can reach the fruit more directly.

Reduce Watering: Cutting back on watering encourages the plant to put its energy into ripening its existing fruit rather than into new growth.

Top the Plant: You can also 'top' the plant by cutting off its top growing point and any remaining flowers. This redirects all the plant's energy into ripening the tomatoes that have already formed.

Ultimately, Monty Don’s banana trick is the last-resort solution for when the season is ending and you want to enjoy every last tomato from your garden. It’s a simple piece of wisdom from a gardening master that can save an entire harvest.

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