Campaign: Diary of a cabbage & onion grower

Diary of a Cabbage & Onion Grower

Week 35-38: August 28 - Sept. 24

Project 1 - Giant Onions

Surprisingly the onions still retained a little green foliage near to their tops, right up until they were lifted for the Malvern Show on September 22nd. The bulb circumference of my largest onion has remained at 30 inches, the same measurement as at the end of August. This has been enough to produce a personal best weight of 11.9 lbs or 5.4 Kg, and that gave me 4th place in the Single Biggest Onion Category. I also entered 3 onions, with a combined weight of 32.14 lbs or 14.58 Kg, in the biggest 3 onion class, in which I managed 3rd place.

Overall, I am very happy with my experience of growing onions in CANNA COCO. There seems to be far less risk of root disease, and I didn’t experience any difficulties with the foliage, which remained green surprisingly late in the season. I am going to try onions in CANNA COCO again next season, but would also like to try some in deep water culture (DWC).

Project 2 - Giant Cabbage

September turned out to be a good month for cabbage growing. It was not too hot, so the best remaining cabbage put on more weight, and feeding was kept simple with CANNA Aqua Vega (EC:1.55). The heart of the biggest cabbage ended up measuring 24 inches in diameter. I got quite excited about this, as it matched the diameter of my UK record cabbage, which weighed in at 124.3l bs (56.4 Kg). The local media caught wind of this and actually came over to do some filming of the cabbage being cut and lifted! My neighbour kindly brought their digger around for the lift, and I’m glad to say it all went smoothly! I carefully removed the roots from the dustbin after cutting, and they had filled the bin and were very healthy. Perhaps next year bigger bins might give bigger cabbage. I’d also like to compare cabbage growth at two different feeding regimes (i.e. EC).

On arrival at the show, we got the cabbage weighed in. I was disappointed that it did not break the 100lb mark, but it was close at 92.5lbs. The good news is that it did indeed win the class! I believe that this has to be the first ever hydroponically grown cabbage to be on the show bench and to actually win. There were roughly 28 cabbages in the class so, in my opinion, it had plenty of competition. Thank you CANNA for giving me this opportunity.

Week 31-34: July 31 - August 27

Project 1 - Giant Onions

Development of the CANNA COCO grown onions slowed down during the hot period last month, and this month they have nearly finished growing altogether. There is a little green foliage on some plants, so a little growth may still occur.

The circumference of the biggest bulb has increased by 2 inches (5cm) during July to reach 30 inches (76cm). This is the biggest onion that I have grown, and I am very pleased with it!

I am very keen to try these onions in Deep Water Culture (DWC) in 2018, as I think that growth will be more rapid. I have kept the nutrient tank at an EC of 1.0 throughout the growing season, and this constancy has made feeding fairly straightforward.

Project 2: Giant Cabbage

Last month I reported that the hot start to July had caused some problems for the cabbage as observed with some tips burning on the leaves. In 2018 I will keep a closer eye on the weather as a good tip is to lower the EC in hot periods when transpiration is higher and to raise the EC in overcast periods when transpiration is lower.

The tip burning seemed to ease as the weather cooled into August. However, in mid-August, we had a few more warm days and this was enough to cause a return of the tip burn problems, which led to the loss of 'one' of my best cabbages. That’s the bad news out of the way! My best cabbage still looks well, and the heart is now 22 inches (56cm) in diameter compared to 18 inches (46cm) last month. The head seems to be very dense, and I think this will weigh well at the Malvern Show. If it was a pumpkin then there would be a tried and tested way of measuring and estimating its weight. Unfortunately, it is nearly impossible to estimate the weight of a cabbage. All I can say is that it looks very heavy with a dense head and very big with healthy outer leaves. I have kept the nutrient tank at an EC of 1.55 during August, and I think that I will continue this for the remainder of the growing season.

The cabbages are still being fed with CANNA Aqua Flores along with the usual additives: RHIZOTONIC, CANNAZYM and CANNABOOST.

I also supplemented the tanks in the middle two weeks of August with CANNA PK 13/14 at the maximum recommended dose of 1.5 mL/L. But this was when I lost one of the cabbages and so I decided not to continue using it since the increase in EC was likely to be pushing them too hard during a time when the EC should have been lowered due to the weather conditions.

If I had had the nerve I would have continued using CANNA PK 13/14, as it seemed to boost the head size, but having lost one cabbage I decided to be cautious.

In 2018 I will perhaps set up two systems and try some different feeding regimes in order to better investigate this. One of the things I will be interested in at the end of the season will be the health and size of the root system. It may be that the roots will need a bigger container next year to support the development of a bigger head.

I am now thinking ahead to harvesting and transporting the cabbage. Usually, I put a sling-strap around the heart of the cabbage to support the head and use a winch system attached to a tractor to pick it up after severing the stump. The cabbage is then lifted clear of the stump, before being lowered onto a plastic sheet big enough to wrap it in its entirety. The photograph below shows a cabbage being harvested in 2014.

The rules of showing a heavy cabbage state that all leaves must be attached to the cabbage if they are to be included in the final weight. If a leaf breaks off it cannot be included in the final weight.

The problem I see this year is the shape of the cabbage, as they have grown so vigorously that the outer leaves are facing downwards and nearly touching the ground. I think we are going to have to turn the cabbage upside down to transport it, in order to avoid breaking the outer leaves. This is going to be very tricky for sure! If we get the rest of the growing and harvesting right, then I believe these cabbages are on target to break records. The next few weeks are going to be interesting and worrying at the same time as a lot can still happen!

Week 27-30: July 3 - July 30

Project 1 - Giant Onions

With Early July being very hot the onions have slowed the pace of their growth and are starting to look a bit tired. The biggest onion is now 28 inches (71 cm) in diameter and is now plodding along. I think I will be trying onions in DWC as well as CANNA Coco next season as I do think they could do very well.

Project 1 - Giant Cabbage

As with the onions a hot start to July has caused some problems, there is some tip burning on the cabbage, but this has calmed down now that the weather has cooled. In early July the cabbage started to look pale so I have upped the EC from 1.2 to 1.55, this seemed to green them up again. The hearts have also started to swell up with the best one at 18 inches (45cm) across now, the whole plant has a diameter of about 7 feet (215cm).

Week 23-26: June 5 - July 2

Project 1 - Giant Onions

My onions still look healthy, we had a week of very hot weather in June, but they seemed to cope fairly well with it. There are a few scorched ends, but overall they are okay. The biggest is now 22 inches (circumference).

I am still feeding CANNA Coco Professional plus at EC 1.0, but am thinking of increasing to 1.2 in July. In an earlier diary entry (weeks 5-8; month 2) I touched on an automated feeding system with feeds between 6:30 am and 16:30 pm. My expectation had been that feeding would occur over a longer period of the day as daylight hours increased. Although this system worked well early in the season, unfortunately a bad choice of transformer blew the controller and I am now watering the onions on a timer 8 times a day through drippers based on a ‘little and often‘ rationale. I will rebuild the control board in the winter when I have more time. The onions are being grown in a very similar way to last year in CANNA Coco Professional plus (with no comparison to other substrates), although the idea was to improve the watering/feeding system this year to see whether I could increase the final size of the onions. For this reason, the technical difficulties with my automated feeding/watering setup have been particularly disappointing. Next year I am hoping to try some onions in DWC by way of a direct comparison with Coco. In weeks 9-13 I touched on the potential for measuring EC and pH directly in the Coco substrate (according to the 1:1.15 extraction method.

Although it’s conceptually attractive I haven’t used this method of gauging feeding requirements yet for my onions as I’m concerned that it may disturb the roots and even possibly leave the onions more vulnerable to disease. During the same 9-13 week period I noted previously that the onions looked advanced compared to previous years and speculated that this may be due to using a lower EC. I still believe this may be true and suspect that raising the EC too high in the past may have led to some ‘burning ‘ of the roots.

Project 2 - Giant Cabbage

My deep water culture (DWC) cabbage in CANNA Aqua Clay Pebbles now look superb, the leaves are nearly touching the ground and covering the bins. If this sort of growth continues I think harvesting them may be a challenge!

The frames that I made up last month are allowing better air circulation around the leaves, supporting the cabbage perfectly and encouraging them to take on a much better shape than last year. Additionally the later seeding date (Feb rather than January) looks likely to give me peak cabbages closer to the dates of the shows than last year, when they were ready a little too early.

In mid June the pH in the recirculating reservoir (measured via a sensor in one of the pots) started to drop rapidly, which I assume is due to increased potassium uptake by the cabbage. On changing from CANNA Aqua Vega to Aqua Flores (EC 1.2) I have noticed that the pH has now stabilized. Feeding continues to be straightforward since I installed the new system to monitor the water via a pH sensor and an EC sensor, which has automated regulation of the EC and pH. I can now leave the cabbages all day without worrying about them, whereas last year I would have to test the water by hand in the morning and guess what they might need during the day. This has taken a lot of guess work away from feeding.

The cabbages have also now started to form hearts at exactly the time I’d expect them too. I am dumping all of the water from the reservoir once a week and putting in fresh as advised by CANNA. I have decided that I am not so good with the Coco cabbage as they are growing a lot more slowly than the DWC plants and, although they are improving fast, it would seem likely that DWC will be better suited to the cabbages than Coco by season end. Although in the previous diary entry, the 2 red cabbage were doing better than the green cabbage in Coco, this situation has now reversed. It’s perhaps not surprising that the green cabbage are now larger, as they are naturally a much larger strain. The variety of green cabbage that I grow is known as Cornish Giant and was originally grown as cattle feed, although there are more efficient ways to feed cattle nowadays. Gratefully, the variety was kept going by a friend of mine George Rogers, who has grown it on his farm for over 50 years. Most giant cabbage on a show bench these days have originated from Georges seeds.

Week 18-22: May 1 - June 4

Project 1 - Giant Onions

My onions are growing better than ever! I am still maintaining the nutrient tank EC at only 1.0 and they seem to happy and responding well. I have lost one onion through a watering error as the pump for that one had stopped working and I did not realise until it was too late. Still, they have been very simple to grow so far, and I think this could be because of the preferred lower EC. They have up to 15 leaves now and the biggest one is 15” in diameter, I think my biggest one last year finished a diameter of around 27” and was just over 12lb.

Project 2 - Giant Cabbage

A lot has happened with the cabbage this month. Early May I made new frames to better support the weight for last year I used pallets but when the cabbage got really big the lower leaves were starved from air and I lost a lot of them. So this year I have supported them with steel frames made from four legs driven into the ground with a welded square on top. I am hoping the leaves will then layer themselves in such a way that they all get air.

At the beginning of May the DWC cabbage looked small on top of their bins but by the end of May they have completely covered both bin and frame. I am also feeding the cabbage with an EC of 1.0 (using CANNA Aqua Vega A & B).

Last year I struggled to keep both EC and pH at the correct levels so I have designed a system to regulate the both of them. It consists of a pH sensor and an EC sensor feeding back to a micro controller of which I have set the parameters at EC 1.0 and pH 5.5. When the water alters outside these parameters automated injectors come into action to maintain the water. It seems to be working extremely well and keeping the water at the right level. The system also records all data so which means I can monitor patterns.

The coco grown cabbage are not looking as advanced as the DWC cabbage but they do look healthy. I am watering by hand at the moment as I haven’t had time to set up a drip system. I intend to sort this out in the next few days. Oddly the Red cabbage are growing far better in the coco than the Green cabbage, it will be interesting to see if this continues...

Week 14-17: April 3 - April 30

Project 1 - Giant Onions

The onions are getting really strong now and with a leaf count of up to 10 leaves. Generally this is really good for me at this time of the year. Looking after them has been fairly easy so far and I have now increased the EC to 1.2 (with COCO A&B & RHIZOTONIC) which it is where it will probably stay for a while now. The onions are not taking too much attention as my automated watering system is looking after them with ease.

Project 2 - Giant Cabbage

The cabbage were moved out into their final position on the 16th April of which there are four being grown by Deep Water Culture (DWC) in CANNA Aqua Clay Pebbles and four grown in CANNA Coco Professional Plus.

Whilst all four DWC cabbages are all giant green ones, due to a last minute decision at the time of planting, I decided to grow just two green ones in Coco alongside two red ones in Coco.

For the DWC cabbages I am using CANNA Aqua Vega and RHIZOTONIC (EC: 1.0). Due to low temperatures at the time of planting, these cabbages went blue for the first few days but are now back to a good colour of green.

I am watering the Coco grown cabbage by hand for the moment until I get a little more time to set it up as an automatic system. At the moment they are being watered from the same reservoir as the onions.

I think next month will be much more exiting with a lot more growth!

Week 9-13: February 27 - April 2

Project 1 - Giant Onions

The onions have really started to show good growth and as daylight hours now exceed 10 hours, the grow lights have been removed. The irrigation system is working well and due to the moisture sensors and programing, I am confident that the young onions are getting just what they need. I am still maintaining the EC at 1.0 (Coco A&B & RHIZOTONIC) with a view to easing it up to 1.2 towards the last two months of growth.

However, I have been advised by CANNA that measuring the EC and pH in the coco is a more accurate way to determine if the plant is being overfed (EC needs lowering) or underfed (EC needs raising),

So far, I have only used 120 L of water in total.

On comparison with 2016, this years onions look to be more advanced and this could possibly be as I am growing at a more suitable EC (maybe too high in 2016).

Project 2 - Giant Cabbage

The weather for March was very dull and wet and so growth was slow. As I have no lights on the cabbage they are totally reliant on natural conditions.

The cabbage are nearly ready to go out. So far they have been growing in CANNA Coco Professional Plus. As per the 2016 cabbage project, four plants will continue in coco and four will be transplanted into CANNA Aqua Pebbles for growing by Deep Water Cuture (DWC).

As you can see in the picture there are also some giant red cabbage plants. After setting a World Record for the giant red cabbage in 2016, I expect to see it heavily contested this year.

Week 5-8: January 30 - February 26

Project 1 - Giant Onions

The final ten onions were transplanted into 44L pots on February 13th. Each pot contains a moisture sensor which has been set to irrigate according to data returned from the sensor. After discussing watering strategies with CANNA I have also set daily watering start and finish times. At present the onions get watered only when needed, but never before 6.30am or after 4.30pm. Of course, this will alter as the days get longer.

By the 26th February the onions had produced a lot of growth. The nutrient tank's EC still maintained at 1.0.

Project 2 - Giant Cabbage

Last year I started the giant cabbage in January and they were ready way before the show, so this year a later start was planned. This years cabbage were started in CANNA Coco Professional Plus on February 14th. The seedlings have been watered with CANNA RHIZOTONIC (2 mL/L) and CANNA Coco A & B (EC: 1.0)

Week 1-4: January 2 - January 29

Project 1 - Giant Onions

Despite this diary entry being for weeks 1-4, the onion seed was actually started on the 14th November. The seed was set for germination in CANNA Coco Professional Plus and the propagator temperature was set at 25 oC. Germination success rate was excellent.

Directly after germination, the lights were switched on and the onions received a full six weeks of non-stop 24 hour light. I have been told that this is necessary for an early sowing to prevent seeding, apparently when the light is switched off for the first time the plant then thinks it is a day old. From day one the onions were watered (when needed) with CANNA RHIZOTONIC and CANNA Coco A&B (EC 1.0). By the 26th of November the seedlings were at the right stage to transplant into 3.5” pots, this is best done at what is called the crook stage which is before the first leaf has fully extended. After transplanting to individual pots, each one was placed on capillary matting.

By January 7th the plants were ready to move up into a larger pots and were potted on into 1.5 L pots.

After experimenting with giant onions in coir during 2016 and seeing the potential, I realised that knowledge and control of moisture levels in the rootzone is very important.

In fact, I knew that complete climate control would be necessary to get the best results. As a result I created and am testing a system to monitor and control moisture levels in the coco, root and air temperatures, relative humidity and light levels.

More to follow as the season goes on...

The Grower:
David Thomas from Cornwall has been growing all of his life after having been born into a farming family. David has always enjoyed gardening as a hobby and some 16 years ago grew his first Giant Pumpkin.

He attended his first UK Giant Vegetable show at Shepton Mallet in 1999. Seeing the vast array of Giant Vegetables on show, David quickly became hooked and has been growing Giant Vegetables in his garden ever since.

David broke his first World Record in 2011 with a parsnip weighing 7.88 Kg at the Malvern Autumn Garden Show. In 2014 David set a UK record at the UK National Giant Vegetable Show at Malvern by growing a Giant Cabbage weighing 56.4 Kg. David broke another World Record at Malvern in 2015 with a cucumber weighing 12.9 Kg.

The Project:
Until recently David has been growing Giant Vegetables traditionally in soil. However, in 2015 David became interested in growing hydroponically having recognised its potential to advance his growing. He now has the bug for this.

Having witnessed David's dedication and drive, CANNA worked with David on a giant vegetable growing project in 2016. CANNA is delighted to be assisting David again to achieve his goals through the CANNA Sponsored Giant Cabbage & Onion Project 2017.

Growing medium: CANNA Coco Professional Plus CANNA Coco Professional Plus (2a)
CANNA AQUA Clay Pebbles (2b)
Plant: Giant Onion Giant Cabbage
Location: Polytunnel Polytunnel
CANNA Nutrient: Coco A & B (5-4-3) Coco A & B (5-4-3) - Project 2a
AQUA Vega (5-3-8) - Project 2b
AQUA Flores (4-4-10) - Project 2b

With a UK Giant Cabbage record already under his belt, David will be growing 4 cabbage plants in CANNA Coco Professional Plus (Project 2a) which we believe will provide ideal root zone conditions not present in soil.

David will also be growing 4 cabbage plants hydroponically using CANNA AQUA nutrient and clay pebbles (Project 2b). A significant advantage for David of growing on a recirculating system is that it uses less nutrients and water than most other systems.

Also, because of a meticulous control of the supply of nutrients with CANNA AQUA during the growth and blooming phase of the plant, and the fact that the plants roots are in direct contact with the nutrient solution, means that the potential yield is high.

However, as always, the onus will be on David to perfect his growing with both Coco and AQUA but we will be there every step of the way to share our expertise.

Furthermore, David will also also be growing 10 Giant Onion plants in CANNA Coco Professional Plus (Project 1). David will also be using CANNA additives (RHIZOTONIC, PK 13/14, CANNABOOST Accelerator and CANNAZYM).