Monty Don wants us to sow sweet peas this October for a very important reason

Wondering when to sow sweet peas? Monty Don – aka the don when it comes to garden ideas – wants us to start planting the perfumed flowers ASAP.

That's right: this is one of those garden trends that is all about timing things just right. And, if there's one thing we know about Monty, it's that he's very into his timings – whether that's telling us when to plant parsley or the best time to cut hedges.

Still, the gardening guru has a very good reason for telling us to start sowing our sweet peas in the next week or so...

When to sow sweet peas, according to Monty Don

'By sowing sweet peas in October you will have bigger plants with a stronger root system that should give flowers next spring earlier and last longer,' writes Monty Don on his popular gardening blog. 

Andrew O'Donoghue, one of the co-directors at Gardens Revived, agrees wholeheartedly, noting that sowing sweet peas in October will provide them with a longer growing season. 

'These cool-season annuals thrive in cooler temperatures and produce more fragrant and robust blooms when sown over the autumn,' he says, adding that the soil should be just warm enough to give your sweet pea's roots a jumpstart.

Andrew O'Donoghue

RHS-trained gardener Andrew O'Donoghue set up Gardens Revived with his brother, Christopher, in 2018  to create a thriving family business. Together, they have worked on residential gardens, listed buildings and gardens, flower shows and large estates with some exceeding 70 acres – many with historical significance.

Before you start digging, though, it's important to know that there is a disadvantage to planting your sweet peas in October: your young plants will need a little helping hand over the winter months if the weather is bad. 

To combat this, Monty Don hacks the whole 'when to sow sweet peas' problem by planting some in October, as well as a second batch in February to spread the risk.

'I sow three seeds in a three inch pot, although root-trainers also do the job very well,' he says, urging amateur gardeners to use a good potting compost rather than seed compost. 

Once this is done, Monty Don says that he pops his sweet peas on a windowsill (or in a greenhouse) to allow them the time they need to germinate.

'Once the first leaves have grown, place outside in a cold frame or protected spot,' he continues. 

'They only need protection from hard frosts, mice and becoming sodden, so do not provide any extra heat. They will be ready to plant out in April.'

Joseph Clark of @JoesGarden fame, is also a big fan of the dual planting method.

Joseph Clark

As a child, Joe spent a lot of time with his great grandmother in the garden, learning about the different plants, growing fruit and veg and spotting all the animals in the garden. Nowadays, Joe utilises his abundance of innovative growing ideas to create easy and fun recipes to help his audience lead more healthy and environmentally-friendly lives (whilst also saving money). He recently launched a gardening subscription box service called ‘Garden with Joe’ which can be found here.

'By sowing your first batch now, you can enjoy a much earlier display than spring sowings. But by also sowing in March/April you will have another round of sweet peas that in my experience will last slightly longer,' says Joseph.

He goes on to note that, at 'this time of the year the garden is starting to slow down, and there are less jobs to do. That makes it the perfect time to tick this job off the list now, instead of rushing to do it with all the other spring jobs, when the garden is all systems go!'

'An October sowing of sweet peas is a great excuse to get outside in the garden in the oft-forgotten autumn months!'

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