What to harvest in September – enjoy the fruits (and veg) of your labour this month

After a long, hot summer of growing, many of our crops will be ready to harvest this month. For those of us wondering what to harvest in September, there's plenty of choice – provided that you're growing the right plants.

Harvesting your fruit and veg after giving them weeks, or even months, of TLC is perhaps the most rewarding job to do in the garden in September.

'September is a prime time for gardeners to reap the rewards of their hard work, says Mark Dwelly, Head Gardener at Audley Villages. 'The season offers a variety of delicious fruits and vegetables that are perfect for enjoying fresh or preserving for later.'

We've rounded up a list of what to harvest in September, with tips from garden experts to help us get the most out of every picking.

What you'll need

1. Tomatoes

First on our list of what to plant in September is a firm gardener's favourite. You might be harvesting the last of your tomatoes this month, especially if you're growing them outdoors.

Learning how to grow tomatoes is really worth your while if you want tasting pickings for salads, chutneys and various other homemade condiments.

You'll know they're ready to be picked once they've reached their full colour. Leaving the stalk attached can prolong the shelf life of your pickings.

'To avoid bruising, cup the tomato in the palm of your hand and use your thumb to break the fruit where the flower stalk swells,' advises Annelise Brilli, Thompson & Morgan's horticultural expert.

But if the fruits just aren't ripening, you might want to try Monty Don's green tomato tips.

Annelise Brilli

Annelise Brilli is the horticultural copywriter for Thompson & Morgan. Annelise caught the gardening bug from her mother, whose tiny backyard was crammed with a huge collection of plants. She is passionate about sustainable gardening and has developed her own wildlife-friendly garden which she has opened as part of Macmillan Coastal Garden Trail.

2. Onions

Onions are a feature of countless dishes, and using home-grown bulbs can make them all the more special (not to mention even tastier). If you're wondering when to harvest onions, you could be lifting the bulbs sooner than you think.

September is the perfect time to harvest onions grown from spring-planted sets or seeds. You'll know they're ready to be harvested once the foliage begins to yellow. Lift them with a fork, but try to avoid bruising or damaging the bulbs.

If any are damaged along the way, use those straight away and dry the rest for two weeks before storing them in a cool, dry place.

3. Potatoes

Learning how to grow potatoes is incredibly rewarding – nothing quite beats the feeling of 'digging for gold' when it's harvest time.

'When the haulms on your maincrops have died, choose a dry, sunny day to cut them off at ground level and leave the potatoes in the soil to dry for up to 10 days,' says the technical team at Harrod Horticultural. 'This will help toughen the skin for storage.'

But how do you store freshly harvested potatoes to help them last longer? 'Store them in hessian potato sacks in a dark, cool, frost-free place,' advises Harrod Horticultural. 'Don’t store potatoes in polyethene bags as this causes them to sweat, which can result in rotting.'

4. Apples and pears

At this time of year, apples and pears are ripening and ready for the fruit basket. If you've learned how to prune fruit trees for a better harvest, you'll likely be enjoying a bumper crop. But how do you know when they're ready to be harvested?

'Apples are ripe and ready to harvest when they come away easily in your hand with a gentle twist,' says the technical team at Harrod Horticultural. 'Pears, on the other hand, are one of the few fruits you should pick before maturity. This will give them time to ripen in the fruit basket and give you more time to enjoy them.'

Make sure you check the fruit over for signs of garden plant pests and diseases and discard any that look damaged.

To ensure your harvests last as long as possible, you'll need to store them in the right conditions. Longevity after picking will depend on the variety, too.

'Early, mid-season or dessert apple varieties won’t last nearly as long as Bramley apples, so leave them on the tree as long as possible,' advise the experts at Harrod Horticultural.

5. Runner beans

Learning how to grow runner beans in pots or the ground is relatively easy, and the plants often crop prolifically, giving you real bang for your buck.

The beans are usually ready to pick from the middle of summer. You'll want to harvest them every couple of days to encourage new pods to form and get the most out of every plant.

'Runner beans are ready to pick when the pods are less than full length, snap easily and the seeds are still pale in colour,' advises the technical team at Harrod Horticultural. 'Typically, this is around 15-20cm long.'

It can be tempting to pull the beans by hand, but this can actually damage the plant, so best practice is to use a harvesting knife, scissors or secateurs.

'Don't make the mistake of leaving them to get too big, unless you are entering the local longest bean competition!' says Andy Tudbury, head gardener at Belvoir Castle. 'I usually find they become stringy and less tasty than ones picked young and tender.'

6. Beetroot

If you've been growing beetroot this year, you might have already enjoyed the roots in sandwiches and salads. If you sowed a little later, or even successionally, delicious harvests could be waiting in the wings this month.

According to Annelise from Thompson & Morgan, the weather has been perfect for beetroot this year. 'The good news is that whilst your peppers and tomatoes may not be enjoying the wet summer, your beets will love it! Cool seasons and plenty of moisture are beetroot heaven, so you should be cropping plenty of sweet, tender roots with no splitting from dry periods.

'Remember to harvest them when small and tender – there’s nothing worse than woody beets!'

7. Summer squash

You might find yourself overcome with ripe squash waiting to be harvested this month, especially prolific croppers like patty pan squash. Don't leave them on the plant for too long, though.

'Turn your back on summer squash for five minutes and before you know it there’s a whopper lying in wait under those leaves,' says Annelise. 'Large, seedy squash are not nice to eat, so just keep checking your plants regularly, cutting them off with a piece of stalk when they are still small and tender.'

The longer you leave ripe squash to grow, the less taste they'll have, so enjoy them as and when they're ready to be harvested.

8. Sweetcorn

Learning how to grow sweetcorn is exciting, and the delicious cobs can be enjoyed in various dishes. When it comes to harvesting sweetcorn, you'll need to rely on a few key signs that they're ready for the kitchen.

'There are so many varieties of sweetcorn that there can be no hard and fast rules as to when to pick,' says Andy from Belvoir Castle. 'The easiest way is to wait until the beard at the end turns brown, then gently peel back a section an inch or two, like you would a banana – if you are greeted with tender yellow corns, then pick one or two cobs to try.

'If you see pale white corn, then simply smooth the skin back over the corns for a few days.'

9. Autumn raspberries

If you've been growing autumn raspberries, the fruits should continue to ripen this month.

You'll know they're ready to be picked when you can easily pull them from the plant. If you're not sure, check the colour – if they look rich and full, it's a good sign they can be harvested.

Remember to check when you should be pruning autumn raspberries to encourage a bumper crop next year.

10. Peppers

Learning how to grow peppers from seed is really rewarding, and whether you're growing chilli peppers or sweet peppers, you might be lucky enough to pick them this month.

Harvesting rules for peppers are more flexible than other crops on our list of what to harvest in September.

'Unlike tomatoes, peppers have the advantage that you can harvest them at any stage, but bear in mind that waiting for the fruit to fully mature will inhibit further fruit production and reduce your overall harvest,' explains Annelise from Thompson & Morgan. 'It can take 3-6 weeks for fruits to ripen from green to red, and if summer is a damp squib like this year, your peppers may not reach full maturity on the plant.

'So, unless the summer is a scorcher, it’s best to satisfy yourself with green peppers, ensuring that you use secateurs and leave a little bit of stalk attached.'

FAQs

What is the best fruit to pick in September?

We've already mentioned apples, pears and autumn raspberries, but there are other fruits which are ready to be enjoyed this month.

'Figs are a delicious late-season treat that also reach their peak ripeness in September,' says Mark from Audley Villages. 'They are a unique and delicious fruit that can be enjoyed fresh or preserved. When ripe, they're soft and slightly wrinkled.'

Many plum varieties will also be ready for picking this month.

What is the best crop to plant in September?

The growing season might be coming to an end, but there are still plenty of vegetables you can plant this month. Some vegetables can be overwintered for an early crop next spring, like broad beans and peas – provided you choose the right varieties. You can also continue sowing salad crops under cover for harvests well into the colder months.

And if you're wondering what to plant in pots in September, there's a broad range of beautiful plants you can add to your garden now.

The list of what to harvest in September is long, so there's plenty to be enjoyed if you've been growing your own fruit and vegetables this year.