Onions have always been one of the main crops that I grow,
even though they are prone to some problematic issues in the gardens.
And for all of the years that I have grown onions, I have relied on planting onion
sets which are small starts or beginnings of an onion plant, which I need to buy in each season.
I have found that planting onion sets to be a quick and easy way to grow onions,
and I have stayed away from sowing onion seeds for several reasons.
But this year I finally switched to growing from seeds for the main crops of onions in the gardens,
including a big variety trial. And I was pleasantly surprised
how successful the crops were, for the most part, and how big some of the bulbs grew!
I have known for a long time that I should try growing onions from seeds,
as there are apparently quite a few benefits. The local community farm has always grown onions
from seed, but the yields always seem to be quite low, producing a
large quantity of very small onions. And the process of sowing all those
seeds seemed to take up a lot of time and valuable propagation space in the spring,
and then a lot of work in the fields transplanting and looking after these crops.
All of that for what seems like a relatively small yield, at least compared to what I had been able
to grow in my own gardens when growing from sets. Using onion sets just seemed easier to me,
and a lot more successful, and it was useful to keep doing same thing each year,
as the consistency meant that I was better able to compare the crops over different seasons.
But I wanted to try seeds partially because there was a much greater
diversity of varieties that I could try. And there is this idea that onion plants
grown from seed tend to suffer less from some of the key issues I have had with onions,
including that they were less likely to bolt, and they may be more resistant to
mildews and other rotting in the bulbs . And apparently onions grown for seeds
could store better, especially when they are grown to be not soo big.
And lately I have wanted to avoid buy in sets every season, especially as they have
not so easy to get in the last few years with widespread disruptions to the supply chains.
I am also becoming more interested in saving onion seeds,
to reduce dependence on suppliers even more. And, perhaps more importantly, I wanted to better
understand the real differences of growing from seeds and growing from onion sets, rather than
relying on the experiences of others, and the only way to really do this is to give it a try.
So this past season I made a big change and decided to try growing
from seeds for all of the main crop onions in all the gardens.
I selected three different 3 varieties, a typical globe shaped variety, a red one,
and a newer hybrid variety, to grow in 3 of the family scale gardens.
In the Intensive and in the No-Dig gardens these seeds were sown as multi-sown soil blocks,
aiming for 3-4 plants at each transplanting station, and for the Extensive Garden
only one seed was sown per cell which were transplanted out to grow as individual plants.
For the large bed of the Simple Garden we sowed seeds from 15 different varieties of
onions in a tray of modules, with about 4 seeds per cell, and transplanted out
8 stations of each variety, trying to make sure there were 4 plants at each station.
And for the Polyculture Garden, we sowed the same 15 varieties,
which were transplanted out as clusters intercropped with other types of vegetables.
Most of the these seeds were sown at the end Jan and transplanted out near the end of March,
though we delayed transplanting the plants for the Extensive and
Polyculture Gardens for a little bit longer.
I didn’t have high hopes for this first planting using seeds, especially in the Simple Garden,
as the tray of seedlings had been overwatered in the cool conditions of early spring and
some of the seedlings had died off. And there were signs of stress in the
seedlings when they were transplanted into the ground, likely because there was not
enough growing medium in the small cells. This was not a good start to a very large
variety trial, and I was tempted to abandon all the seedlings and to look
to buy some sets to replace the crop, but we went ahead with the planting instead.
The transplants for the other gardens were in much better shape, especially with the stronger plants
growing in the soil blocks that were transplanted into the Intensive and the No-Dig gardens.
All the plants eventually started to grow well, and we looked after them well enough,
and we tried to keep the beds free of weeds until the bulbs had almost fully developed.
And we had good growing conditions for most of summer, with more warmth and dry conditions
that we normally get, and there was very little signs of mildew or rot on any of the varieties
of onions, despite the rains coming in a few weeks before they were harvested.
I was surprised how big many of the plants grew, and they developed some really big bulbs
despite the high density of planting in the No-Dig, the Intensive and the Simple Gardens.
I really didn’t think these onions would get so big, and they were so much larger than
anything I had seen produced on the local farm, including the crop from this year.
I haven’t weighed the onions yet, as I want to wait until they are dry to get
more appropriate data for comparison, but the onions we grew this year are comparable
to a crops of onions I would have grown in a good year in the past using onion sets.
The biggest issue I had was bolting, where the onion plants prematurely started the process of
using all their energy to develop a flower head, instead of producing more onions for us to eat.
I didn’t expect this, as I had heard that onions
grown from seeds are less likely to bolt than the ones grown from sets.
This bolting was especially bad in the No-Dig Garden, with over 60% of plants
of the standard variety, 35% of the red variety and 25% of the hybrid variety plants bolting,
translating to a total of about 40% of all the plants being wasted in this garden.
In the Intensive Garden, only 20% of the plants bolted, which is still too much,
with 26% of the standard variety bolting compared to the 60% in the No-Dig Garden.
But none in plants in the Extensive or Polyculture Gardens bolted, and only three
or four plants in the big crop of the Simple Garden bolted, even though there were almost
400 plants from the 15 different varieties. It is possible that the higher density of
plants in these gardens could have led to this bolting, if they had become stressed
because of competition or some other factor. But the three larger plantings of the No-Dig,
Intensive and Simple Gardens were all planted with the same density of plants,
with 4 onion seedlings planted at each station, 30 cm or one foot apart each way.
But in the Simple Garden we ended up with only 3 plants per station on average, probably because
the stressed seedlings early in the season naturally thinned out some of the plants,
so there ended up being about 25% fewer plants overall.
This could have be enough to prevent bolting, but in some sections of large Simple Garden patch
there was a full density of 4 plants per cluster, and those plants would have been just as crowded
as the ones in the No-Dig and Intensive Gardens but this didn’t trigger the plants into bolting.
So I think something else is going on, or it is not simply the density
of the plants that is the issue. Perhaps it is related to excessive
fertility or a nutrient imbalance in the No-Dig and Intensive Gardens.
Or the seeds may have been sown too early, leading to the plants being able to grow
too big before they started to develop the swollen edible bulb at the base.
And with the higher density of plants this could have triggered the bolting of many of them.
Whereas in the Simple Garden the transplants were in poor condition and had a slower start.
And the potentially lower levels of soil fertility in this garden
may have led to slightly slower growth, so the plants didn’t grow large enough
for the density to become a problem, even though they did end up growing quite big.
I probably need to find a balance between how early the seeds are sown,
how much space each plant is given to grow in, and how big of an onion we want to harvest.
And this depends on the soil fertility that is likely to be available,
and on the growing conditions which is something that we cannot control.
I suspect that this balance was achieved in the Simple Garden, more by accident than any planning,
but there wasn’t that balance in the other two gardens where bolting occurred,
possibly because there was just too much growth early in the season.
But there could also be another factor that I am not considering.
I was very pleased with the large batch of 15 different varieties of onions in the
Simple Garden, especially after the rough start with the poor quality seedlings.
I had expected some varieties to do well, and some to really struggle, and others would be badly
affected by mildew or some other disease issue. But all of varieties produced a respectable
yield this season, or at least more than I was expecting, and some of them produced
quite a big crop of really large onions, bigger than I have ever grown before.
But the yield of the crop is only one factor to consider, and I am really looking forward to
tasting the differences between all of these types of onions, and how different varieties can be used
for different purposes in the kitchen, which is something that I have not really explored before.
Some varieties had a few bulbs that split, others had some rotting plants and a few bolted, but I am
not sure if it is just a random occurrence or a sign of an issue with that variety.
Another big issue is storage, as no doubt there will be significant
differences and in how well the onion varieties will keep in useable condition,
and for how long into the sprig next year.
I had originally planned the sowing and density of this crop thinking that the average onion
size would be smaller, based on the idea that they might store better than the larger bulbs.
But this is only really an issue for 2 to 3 months of the late spring, and for the rest
of the year, a crop of larger onions, which are easy to peel, is definitely a benefit.
There were a few soil blocks of onion seedlings leftover from the gardens,
and I decided to transplant a few seedlings from the three main varieties into grow bags
with different soil mixes or growing medium. This was not a useful comparison of course,
but I wanted to see how they would grow, and despite neglecting them for a lot of the season,
and letting them dry out too may times, some of the bulbs grew surprisingly big.
The red variety growing in a bag of soil with a bit of low quality compost mixed in did poorly,
or not as well as the same plants in other gardens, and one of the plants bolted.
The hybrid variety growing in a bag of soil amended with compost,
some balanced fertiliser and some perlite did well, producing three nice size bulbs, which
were about the same size as the other plantings. But the conventional variety grown in bagged
potting compost amended with a balanced general fertiliser, produced 4 bulbs that
were all substantially bigger than the plants grown in the soil in the gardens.
I did not expect this, and I am not sure how such big plants could have been produced from
such a small volume of growing medium. And I am surprised that none of these
pants bolted, as they were the same variety that bolted the most in the No-Dig Garden,
which seems to go against the idea that stress and competition led to bolting.
It seems that these plants benefited from the good fertility, and the warmer root zone in the
grow bag, at least compared to the soil in the gardens, but I am surprised how little volume
was needed for the roots of these plants. This small experiment ended up being
surprisingly useful, as it led to a lot of questions and possibilities.
Switching to seeds for all of the main crop plantings this year,
could have been a disaster, but it ended up being a really good crop, for the most part.
And there is still so much to learn from this year,
including the taste and possible use of the different varieties, the storage potential,
as well as a more accurate yield comparisons once all the bulbs are properly dried.
I will need to repeat the variety trial, to see what works in different weather
conditions, and I am planning to sow a trial of overwintering plants in one of the polytunnels.
I think the divergent results from the three grow bags was really interesting, and I’m
looking forward to exploring the possibilities of using grow bags like this a lot more.
And I plan to start saving onion seeds, so that we don’t need to rely on buying
in sets or buying in seeds, but because of cross pollination risks, I can only really
save seeds from one onion variety each year. And I want to make sure that it is actually a
useful and appropriate variety that doesn’t bolt too much, before getting too deep into
the process of building up my own seed supplies for the future and to share.
I wish I had started exploring growing from seeds a long time ago, and this has been a
very valuable lesson for me, to not be put off by the mediocre experiences of others, and that
there can be a lot of benefits from just trying things out, if I have the time and capacity.