Grow juicier tomatoes with Monty Don's one-ingredient homemade fertiliser - but beware, it's 'vile'

Tomatoes are a favourite among gardeners due to their ease of cultivation, but they require more nutrients than most other plants.

Gardener's World's Monty Don suggests that tomatoes will yield larger and tastier fruit if adequately supplied with potassium, an essential nutrient for fruit production.

The gardening expert also revealed that a homemade potassium fertiliser can easily be made to give crops a boost, using just one common garden plant.

Monty explained: "Potassium is what plants need to form good flowers and fruit, and fruiting flowers like tomatoes and gooseberries have quite a high potassium demand."

"You can boost that at this time of year and improve fruit production. One way of doing that is to go to a garden centre and buy liquid or granular fertiliser, but there's no need as you can also grow your own supply of potassium really easily through comfrey. ", reports the Express.

Comfrey is a typical garden weed recognised for its large hairy leaves which are very rich in potassium and other nutrients needed by tomatoes such as calcium.

Monty stated: "Its main use to me in this garden is to provide the raw material for a liquid feed that's high in potassium.He further cautioned: "A note about comfrey is that once it gets established it has deep roots and it's quite hard to get rid of. However, you shouldn't get rid of too much as it really is so useful."

How to make a homemade tomato fertiliser

You will need:

• Comfrey leaves

• Large waterproof bucket with lid

• Large stone to weigh on a bucket

• Plastic bottles such as old milk bottles

• Watering can

To start, carefully harvest comfrey leaves from the plant, making sure to wear gloves as they can sometimes irritate the skin.Strip away any flowers and stems, then finely chop the comfrey leaves before packing them into a watertight container.

Pour clean water over them until the container is full.

Secure the lid on tightly and stash it somewhere out of the way in your garden for several weeks, allowing the contents to decompose and turn into a liquid state.

Monty explained: "The idea is to loosely fill a bucket or just put what leaves you've got, then put water in on top of that and leave it to brew for three weeks. It's crucial to use a lidded container and weigh down the lid with a stone because, while beneficial for tomatoes, decomposing comfrey emits a horrendous odour."

Monty warned: "Then when it is properly made, it will form a black vile-smelling sludge, and I'm not exaggerating it smells disgusting...it's covered not to protect the brew but to protect us from its vile smell.".

After about three weeks, you'll find that the mixture has transformed into a pungently scented brown liquid. Transfer this to plastic bottles and store in a dark and cool setting.

When the time comes to feed your tomato plants, strain off the leaves and dilute the brewed fertiliser - one part comfrey extract to 10 parts water is ideal. The more concentrated the fertiliser, the more dilution required.

Then place it in a watering can and use it to feed your tomato plants, where you will help give your tomatoes a boost to get bigger, juicer and better quality fruit for your next harvest.