This past year grew a big trial of 15 different varieties of onions, all grown from seeds, which
is something that I had want to do for a while. I decided to replace the usual large crop
of onions in the Simple Garden that we have grown in the past using onion sets,
replacing it with multi sown modules of onion seeds, with enough plants of each variety to
hopefully be able to make a decent comparison. Overall I was really impressed with this crop,
as there was a much bigger yield than I had expected from onion plants grown from seeds,
even though the seedlings were stressed earlier in the year with poor conditions.
And fewer of the onion plants in this large batch bolted or started to produce seed,
compared to two of the other gardens where we also grew three of these same varieties.
And with the good weather that we got this year,
there was good yield from all the different varieties, with enough
variation in yields to start to figure out which varieties I might want to grow again.
A lot of the varieties that we grew are fairly typical types of onions, with a globe or round
shape, and a yellow or straw coloured skin. The first one, a variety called Ailsa Craig,
was one of the varieties that we also grew in the other gardens, where quite a few of
the plants of this variety bolting in two of the gardens with more densely spaced plants.
With the slightly lower density of plants in this variety trial, only two of the 28 plants bolted,
and one of the bulbs split at the base, but the rest produced a good yield of large bulbs which
were slightly elongated, but I think that was more because the plants were squished
together in the multi-sown stations. Looking at one bulb that I cut open,
the top of the bulb wasn’t so tight which might indicate an issue with storage,
but apart from that and the possible tendency to bolt, this looks like a decent standard
variety that can produce a lot of onions. Another globe shaped variety called Rijnsburger
5 produced decent sized bulbs, but something seems to have happened with a lot of the plants,
with a few of the clusters missing, and I am not sure what happened.
The inside of one bulb that I cut open had pronounced drying or decay of the layers at
the top of the bulb, which reduces the amount that is edible and may affect how long it will store,
but another bulb of the same variety had a tighter top which is what I want to see.
So I won’t know how common this is with this variety, or with any of the other varieties,
until we cut open a lot more of the bulbs. The Sturon variety is one of the few varieties
that I have grown before from onion sets, and this batch grown from seeds produced nice
quality bulbs, some of which were slightly flatter in shape, with no apparent issues,
and looked good on the inside. But they were smaller than the
others in this first set of varieties, producing only a moderate yield.
Each of these 3 similar open pollinated varieties seem to have issues, either with bolting, rotting,
missing plants or smaller yield, but based on this one trial I’d probably pick the Ailsa Craig
variety to grow again, at least for producing large quantities of conventional types of onions.
The open pollinated Rose de Keruel variety looked like a fairly conventional onion on the outside,
with a slight rose coloured skin, but this rose colouring
continued into the centre of the bulb, producing quite an attractive onion.
This variety produced a relatively high yield, but unfortunately 3 of the bulbs were rotten at
the base, and another had split open from the inside, indicating it might not be so
successful in this climate, especially if we get cool and wet summer weather.
But the remaining bulbs ended up being larger than most of the other varieties,
weighing over 400g each on average, so perhaps it is worth growing again.
There was one other variety called Stuttgart Giant, that I would generally include in this set
of straw coloured onion varieties, with a similar colouring inside that many of the others had,
but it had a distinctive flattened shape that differentiates it from the other varieties.
The yield of this variety was mediocre,
and it had the smallest bulb size out of all the varieties, but the shape and colour was
quite attractive and it didn’t seem to have any issues with bolting or rotting.
One of the two hybrid varieties that we grew in this trial,
named Hytech produced quite a consistent crop of well shaped, fairly large onions,
and the third highest yield of all the varieties. None of the plants showed any signs of bolting,
but there was one small plant that rotted in the garden, so not sure if this is significant.
The other hybrid variety called Santero, was one of three varieties that I grew
in the other gardens, where quite a few of the plants had bolted,
but none in this trial started to produce the flower stalk prematurely.
One bulb started to rot before it dried, but the rest of the bulbs seemed decent quality, but the
bulb size and yield was significantly smaller than the other hybrid type, and seemed less consistent.
Based on this one trial, and a relatively small sample size, I am not sure it is worth the extra
cost of the Santero hybrid seeds, but I think it might be worth growing the Hytech variety again.
Two of the varieties produced bulbs that were
definitely quite a bit bigger than the others, and both had paler yellow skin.
The Bedfordshire Champion variety produced some of the largest bulbs, weighing 540g each on average,
with some of them quite a bit larger, though this was partially because some
of the seedlings in a few clusters did not survive the start of the season.
And a few of the larger bulbs ended up splitting open at the base, more than with many of the other
varieties, and this reduced the useable yield that we harvested, but the inside of the onion I cut
open seemed in good shape, though fairly typical. The Globo variety produced the biggest yield of
this trial, of consistently large bulbs that didn’t seem to have any issues,
and inside there was a pronounced red banding which really accentuated the different layers.
The plants were still growing strong when they were harvested in September, with no signs of
the usual lodging that occurs with many of the other varieties when they stop growing.
So this crop might have grown even bigger, and if I wanted the largest yield of big onions, this
Globo variety is definitely one to grow, though apparently it isn’t great for long term storage.
We grew three red onion varieties as part of this trial, each producing beautiful
globe shaped onions, with a deep red or purple skin, and a similar purple colouring inside,
though they didn’t produce as well as most of the straw coloured varieties.
The Karmen variety had a slightly larger yield of slighter bigger bulbs than the other two
varieties, but a few of the onions rotted before they dried, and one was split at the base.
We had also grown this variety in the other gardens, and with similar lower
yields compared to the more typical coloured varieties, and a few of the bulbs split at the
base with this variety in the other gardens. The Red Baron variety had a smaller bulb size
and the smallest yield of the three, but only marginally, and a few of these onions ended up
splitting at the base, and I wonder if this is more common among the red onion varieties
The Robelja variety was similar size and yield to the Red Barron variety,
but didn’t have any of the roots splitting, but the top or neck of the bulb was quite wide, though
with a small sample size like this it is hard to tell if this is a characteristic of the variety.
There is not much difference between these three varieties in terms of yield,
but the Red Baron variety seemed to produce bulbs that were tightly wrapped,
with a thinner closed neck or top, which might indicate that they will store better.
Three of the onion varieties that we grew developed much more
elongated bulbs, which I have not seen before. The Cipolle di Tropea variety produced bulbs that
looked stretched, with a range of shapes from more bulb like to more elongated, but they were
quite large and had beautiful dark pink coloured skin, that continued into the inside of the bulb.
The one bulb that I cut opened seemed separated into several distinct sections, which is
interesting, though I am not sure how common it is to the variety, or if this affects how it can be
used in the kitchen or how long it will store. This plating of this variety included a large
Globo onion that had obviously grown from a misplaced seeds, and even without
this one large plant, the yield was quite good, but it could have been even higher.
The Long de Florence Simane variety had quite similar elongated bottle shaped bulbs, with a
very similar colour, and similar colouring inside the bulb, though with more layers.
This variety had similar yields and bulb size to the other elongated variety, but quite a few of
these bulbs still had green shoots, either as regrowth or leaves that had not dried off yet,
which were covered with a black fly or aphid. This could be cut off for storage, but it seems
that the bulbs of this variety were not going into the dormant stage that was common with all
the other onions in the trial, indicating that they would not store for very long.
The Tosca variety had a similar elongated shape,
though more cylindrical that the other two, and a straw coloured skin,
and internal colouring similar to many of the typical straw coloured varieties.
These onions were quite a bit smaller than any of the other varieties in the trial,
producing the smallest yield, less than half the weight of some of the more productive varieties.
Looking at the yields of all of the different varieties,
as they were laid out along the length of the bed, there is a definite slope, with the
plants at one end of the bed seeming to produce a higher yield that the plants at the other end.
This could be just a coincidence with the arrangement of the varieties in the bed,
especially with two of the larger producing varieties at one end of the bed.
But it could also be due to changing soil quality or fertility along the length of the bed,
with the larger yielding varieties towards one end of the bed having better growing conditions.
But the total harvest from this large bed in the Simple Garden,
including the less productive varieties, is significantly better than in the previous five
seasons that I have grown a big batch of onions as part of the crop rotation of this garden.
An overall yield of almost 9.5 kg/m2 is significantly better than any other year,
and a lot of this increase could be due to the relatively good growing
conditions that we had this past year. Especially compared to a few crops a
couple of years ago that had really reduced yields due to serious issues with mildew.
But the gradual increase since then, could be because of improving soil health and fertility
in this garden, and the use of better disease resistant varieties, but until this year I had
only grown a single variety each season from onions sets that I had bought in.
I used to only grow onions from sets, partially because I felt
that they were easier, and I had also been put using seeds off by the not
great crops the local community farm was getting when growing from seeds.
This season was the first time I grew a large onion crop from seeds,
and I have been been pleasantly surprised with the results, even with all the different varieties.
It was great to get a good growing season for this first trial of onion varieties.
But I realise that variety trials like this should generally be repeated over a couple of seasons,
as different varieties respond to changing weather patterns in different ways, and can
have different levels of disease resistance. So I am planning another similar trial for the
same garden next year, and I have already sown another batch of seeds for an overwintering trial
in one of the polytunnels, and I am interested in harvesting them as fresh, immature plants,
as apparently some of the varieties are typically grown for this rather than for storage onions.
I don’t have a lot of experience growing onions for harvesting at different times of the year and
at different stages, and no doubt I would end up selecting different varieties for different uses.
I still need to figure out which of these varieties will store better than others, as this
is a really important factor for ensuring that we have access to home grown onions all year round.
And I plan keep a few onions of each varieties over the winter and into
the spring, essentially waiting until each variety degrades, sprouts or rots.
And of course another key factor that I have not yet explored is the taste of all these onions,
and how well they cook, and what ones are better for different uses in the kitchen.
But I still don’t know how to do an effective taste test with so many varieties of onions,
especially if I want to cook them in several different ways.
This will be a time consuming, though probably enjoyable task,
but I am not sure I’m looking forward to sampling raw onions from 15 different varieties.