How Organic Growing Techniques Produced a Record-Breaking Onion

How Organic Growing Techniques Produced a Record-Breaking Onion

It all started with a dream, and a bulk bag of Eco-Life soil.

Gareth Griffin, a veteran onion grower from Guernsey, UK, decided he would try to beat the world record for heavyweight onions. For this monumentally competitive task, he knew that he would need to fill his beds with the best mix possible. That’s when Gareth reached out to us and we convinced him to invest in 1000L of the finest organic living soil mix money can buy: Eco-Life.

Roll on to September 2023, and Gareth absolutely smashed the world record by producing a monster onion weighing in at a whopping 19lb 12oz (8.97kg)! Gareth entered his colossal onion into the National Onion Championship class at Harrogate Autumn Flower Show.

Here at Ecothrive, we’re still buzzing with excitement. Firstly, we’d like to heartily congratulate Gareth on this incredible achievement. We are delighted and proud that one of our esteemed customers just shattered the world record!

A Huge Leap of Faith with Eco-Life Living Soil

In January 2023, Gareth reached out, intrigued by the distinctiveness of our Eco-Life living soil. We delved into the meticulous 2-3 week production process that births our biologically active, nutritionally dense soil, designed to sustain plants throughout the growing season with minimal additional inputs. Convinced and captivated, Gareth ordered a bulk bag, marking the inception of a journey that would etch his name in the annals of onion-growing history.

The Art and Science of Growing Giant Onions

Giant onion cultivation is a craft mastered by the patient and persistent. Seeds sown indoors under grow lights during October-November are meticulously nurtured and then transplanted into greenhouse beds in spring, culminating in a harvest at summer’s end.

Global Acclaim for Gareth’s World Record Onion

The echo of Gareth’s monumental achievement resonated globally, with reports flooding in from the USA to Australia and India. The universal culinary staple, the onion, had been supersized, and the world was in awe. The revelation that Eco-Life living soil was the silent partner in this global sensation has piqued the interest of growers worldwide.

 How on Earth Do You Go About Growing a 9kg Onion?

The influx of inquiries from aspiring growers eager to replicate Gareth’s success with exhibition onions using our soil and amendments was overwhelming. To quench this global curiosity, we reached out to Gareth for an in-depth insight into the cultivation process of his 9kg world-record onion:


 Where did the world-record giant onion seeds come from?

I got the seeds from another onion grower called Nick Brake; he came first at Harrogate in 2018. I usually use seeds from Peter Glazebrook who has held the world record for an onion several times.

How was the weather this growing season overall in Guernsey?

It was very similar to mainland England by all accounts. Hot and dry spring followed by a wet summer. Not a great growing year, but it was quite mild without too many really hot days so I think that must have helped the onions somewhat.

How long have you been trying to grow big onions? What got you into it to start with?

I first started growing Robinsons’ Mammoth onions outside, 35 years ago, then moved over to Kelsae, and grew them for 10 years until my dad started getting better weights than me at the local show. The last year he exhibited he managed 7lbs 12 oz. After he died I decided to start again but it was after going to Harrogate and meeting Peter Glazebrook in around 2010 and getting his seed and advice that I really got hooked on growing them. I managed to grow a 17lb 14 oz in 2014 but have rarely gotten over 14lb since, until this year.

Can you explain how you grew your onions this year?

Seeds were sown in the last week of October in a potting compost for seeds, then placed into a heated propagator.

They got potted on at their “crookneck” stage into 5cm square pots and put in a grow room using T5 propagation lights. I kept the lights on for 24 hours light for 6 weeks, then reduced the light to 10 and a half hours of daylight with 13 and a half hours of darkness. This simulates a spring day and keeps them growing leaves instead of bulbing.

I re-potted as required when roots completely filled pots, my potting stages were from 5cm > 1L > 3L > 11L, all using square pots. The soil mix used during these stages was slightly different each time, from a seedling mix, into a lightly fertilised mix then the final pot was more heavily fertilised ‘M3’ mix. Through this propagation stage, I increase the length of time the grow lights are on to match the natural day length outdoors.

Propagtion stage under T5 grow lights

Finally, I planted out the best onions on 18th February into raised beds constructed with 50mm Kingspan insulation boards. Two beds were designed to fit 4 plants, their size is 210 long x 60 wide x 60cm high. With the Kingspan offcuts I made another 2 beds to fit two plants in each, their size was 140 x 60 x 60cm

Each bed was fitted with automatic drip irrigation, six inches below the soil surface, this keeps the soil dry around the base of the onion to minimise diseases. The insulation boards were used on the sides and the base, I drilled holes through the base to allow good drainage. I also installed some heat mats in the beds to keep the soil temperature up in spring. I have used soil warming cables in the past but I find they fail too easily, so I now use warming pads.

What about the soil in the beds, you did a trial this year, right?

Yes, this year I experimented, the three beds were filled with three different soil mixes. One was your Eco-Life living soil, one was an organic peat mix and the other was my usual M3 mix. Each bed had four onions in it.

Heavyweight onion beds ready for planting

I also rejuvenated an old bed of John Innes No.2 soil with your soil amendment Life-Cycle. That bed is 300 x 50 x 50cm and I used 2kg of Life-Cycle mixed into the top 6-8 inches of soil with a barrowful of well-rotted horse manure.         

How often did you water, and how do you judge when it needs water?

After planting out in March, I hand-watered for the first month or so, just a few times a week as and when they needed it. Around late April I began drip watering daily for between 2 and 5 minutes depending on how warm or bright it is that day, and the day before. I did use a basic moisture meter with 2 metal probes and 1-10 micro-irrigations daily for moisture, however, I find these pretty unreliable so I think perhaps it was more luck than judgment on some waterings!

Sounds great, how did the onions set off? Did they start growing at a similar rate or were they any signs of some being ahead early on?

They all grew pretty vigorously as expected without any feed for the first few months. The onions in the M3 and Eco-Life started off the best, then I could see within the first month that the Eco-Life beds were slightly ahead.

I was feeding one of the other beds with organic liquid nitrogen-rich feeds, and I also used some feed with the M3 but kept on just water to start with for the Eco-Life.


 Did you use any of the Life-Cycle or Biosys microbial tea I sent you?

No, I didn’t use any of the Biosys, I completely forgot if I’m honest! The onions in the Eco-Life were growing really well so I didn’t think I needed it. Then, around 3 months after planting I had some yellowing of the leaves in the Eco-Life bed. That’s when I called you and asked your advice.

Yes, I remember you calling. We thought it could have been a touch of over-watering because you were getting a bit of run-off from the beds, and a bit of low nitrogen because that is used up quickest and most easily flushed out.

Yes, that’s right, on your advice I drilled a hole in the side of the Kingspan and cored out some of the soil down low in the bed. It didn’t seem too wet, but moving forward I was more mindful about watering, and I also gave them a feed with half-strength organic high-nitrogen feed.

Ecothrive living soil grown giant onion in mid summer

Did you use any other feeds later in the seasons with the Eco-Life bed?

Around mid-July started giving a liquid high potash feed which I’ve always done to help firm up bulbs, I really think this helps to bulk up their weight. I use water-soluble potassium sulphate, so nothing fancy.

 I know onions are prone to a few problems through the season like pests and disease, how did yours fare this year?

They were all fine until late July, unfortunately, I had a severe infestation of thrips while I was away on holiday.

I was devastated when I got back, the thrips had done so much damage to the leaves it had pretty much finished them off! Silvery white patches of death all over them!

Because the leaves had died back so much I didn’t water or feed during August as I didn’t want onions to sit on wet or even damp soil while no evident growth taking place.

So when did you pull the onions out of their beds?

They were all lifted the four onions on September 12th.

 The weights of the onions from the Eco-Life bed were:

·         19lbs12oz (world record)

·         18lbs 4 oz,

·         17lbs 8 oz

·         14lbs 10 oz

Amazing! What about the re-used soil bed you amended with Life-Cycle?

That produced very firm bulbs ranging from approximately 12 lbs to 15 lbs 2 oz. All the onions I enterd into the Harrogate show were grown with your soil or amednments and I won with the heaviest set of 3, as well as the single heavyweight.

Can you tell us about the weights achieved from the two other beds?

The weights were still good but were around my usual average weights. Mostly around 13 to 14 lbs, with one just topping 15lbs.

Were there any visual differences in growth between Eco-Life and the other beds? Did the finished bulbs have any different characteristics or were they just heavier? Were the winning giant onions more elongated, for example, or firmer?

The finished specimens in the Eco-Life bed and the Life-Cycle rejuvenated bed were certainly firmer onion bulbs. In my other two beds, there were several I had to pull out as they went soft or were showing signs of botrytis. All onions in both the Eco-Life and Life-Cycle beds were bench-able, which just shows there is something about the soil and amendments that are working together beautifully.

So, now you have the world record, are you going to hang up your gardening gloves or do you have plans to go bigger next season?

Go big or go home they say! I’ve got a few plans for next year that I think will help. I’m going to dig out 2 beds and replace them with Eco-Life soil and your new peat-free soil to try. The old Eco-Life bed that grew the world record I will rejuvenate with Life-Cycle and go again. I hope I don’t get pink root which is quite a common disease with big onions. That’s why I used insulated beds as pink root can become more problematic in warm soil, so the insulation is useful as it helps to keep the soil cool.

I’ll use more predatory insects this year to keep the thrips at bay. I think if the thrips hadn’t come along and devastated them in July, I could have hit the often talked about 20lb onion! When I lifted the biggest onion I was just less than 2oz under 20lb, so it lost a few ounces on its way to being weighed at Harrogate! Knowing I was so close to 20lbs is a huge incentive to keep trying!

Early in the season I grew under T5 lights, but I’ve heard some good reports about LEDs grow lights, so I’m going to try a few Daylight LEDs from Maxibright and see how I get on.

I’ll also be more mindful about the nitrogen depleting out of the bed over time and use some a bit earlier in the season to avoid running into any deficiencies.

What seeds are you going to be using next season?

I’ve still got a few Nick Brake seeds from last year, so I’ll definitely be using those, but I’ve also got some fresh seeds from Peter Glazebrook.

Any final words for aspiring giant onion growers out there?

I must give proper credit to Peter Glazebrook, if it wasn’t for Peter sharing his seeds and knowledge about giant onions I would never have achieved this world record. When you’re growing championship onions, you’re already standing on the shoulders of giants.

Gareth Griffin with world record 19lb 12oz onion

Reading next

From Soil to Style
What the Fuzz?

Leave a comment

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.