Microgreens have become very popular in recent years, and seem to be a key crop for many
market gardeners, especially in an urban context.
It's been fascinating to watch the development of this relatively new crop or method of growing,
and to see the diversity of different techniques that other growers have been pioneering.
I’ve learned so much about this from watching videos from other growers, although I didn’t
think it was so relevant for me, given the context and scale I grow in.
Microgreens are typically presented as a high value product, that is produced within the
context of supplying high end restaurants or access to wealthy urban markets.
I didn’t get the sense that it was a useful crop in the context of people growing their
own food, or when supplying a local rural markets and small communities, like I’m
in.
But late last year I thought I’d try growing microgreens, as I was interested in exploring
this way of producing food, and to try to help fill a bit of a gap in supply of salad
greens over the winter.
Having grown quite a few batches since then, and tried out a number of different methods,
I have now changed my opinion about microgreens.
Microgreens are quite a bit different from other methods
of growing salad greens or other vegetables.
Basically it is harvesting plants at the very beginning of their growth, just after they
have started to produce leaves, and a new batch of seeds has to be sown for the next
harvest.
Growing microgreens is not really viable unless you can get access to large quantities of
inexpensive seeds, and even then it can be quite expensive compared to the amount of
harvest that you can get.
There is a huge diversity of different types of plants that you can grow in this way, though
I’ve generally stuck with peas, sunflower and radish, plus occasionally some kale.
This type of cropping has a very short growing cycle, with only 2 to 4 weeks from sowing
the seed to harvesting, depending on type plant and growing conditions.
Microgreens are often grown in flats or trays of growing medium or potting compost, generally
inside a polytunnel or some other type of controlled growing environment.
Some other growers have had success in producing microgreens directly in the garden soil, and
although this seems a bit less common I’ve had pretty good success with it.
I started growing microgreens in flats or trays late last autumn, and I grew them in
a heated propagation space that I had built, which was going to be empty over the winter.
I was using a variety of types of trays including the wooden flats that I had built for raising
seedlings in soil blocks.
It seemed a good way to make use of this infrastructure and equipment at a time when they were not
needed for other uses.
I was surprised that they grew reasonably well despite the low light levels of the winter
months, although there were some losses and other issues as I figured things out.
But because I was growing a new batches every few weeks or so, losing an occasional batch
wasn’t such a big deal for me.
I also found that the quick turnover very useful, as it enabled me to learn quickly,
much faster than with conventional growing, where I often have wait until next season
to try again.
It was also interesting to get into the weekly routines of soaking seeds, and spreading them
out onto the flats of growing medium or potting compost.
And I found that keeping the flats stacked in the warmth inside my house for a few days
after sowing, really sped up the germination rate, before moving them to the propagation
space to grow, Later in the season when the propagation space
started to fill up with other seedlings, and as the weather warmed up, I started to move
the flats into the unheated Polytunnel Garden instead.
I generally harvested as much of the crop as I needed each day, and it turned out to
be a very useful supply of salad greens throughout the winter and into the early spring.
Later in the spring I switched to growing microgreens directly in the soil in one of
the beds of the Polytunnel Garden, mainly because the propagation space was starting
to fill up with other plants.
But I also wanted to move away from sowing them in trays or flats, because I didn’t
wan’t to continue to buy in more and more bags of the growing medium.
I set out one garden bed that was 1 meter wide and 6 meters long, and sowed one square
meter at a time with a different mix of types of seeds, with a new batch being sown roughly
every week.
By the time I was ready to sow the 7th batch, the first batch would have already have been
harvested, allow enough time for the the remains of this previous crop to be dug in.
For each sowing I would ensure that I started with a fine seedbed, before evenly spreading
the seeds directly onto the flat surface of the soil.
I would then cover the seeds with a thin layer of additional soil or compost, which apparently
helps the growth in this context, though I haven’t done much of my own exploration
about how useful this is.
Once the seeds were watered in, I covered the section of the bed with a plastic lined
board, which was weighed down by a pallet.
It seems that this weight above the seedlings helps them to root properly, and prevents
the seeds from drying out, but it needs to be removed a few days later so that the seedlings
can develop leaves.
I found that this method of growing microgreens directly on the surface of the garden soil,
was an effective way to grow the amount of microgreens that I could manage in a week,
and I was surprised how productive they could be.
I was regularly harvesting about 2.5kg each week of very tasty and nutritious microgreens
from each square meter of bed, after only 2-3 weeks of growth.
With a continual replanting, a bed dedicated to growing like this could potentially produce
a lot of microgreens over a full year.
As this polytunnel started to fill up with other summer crops, I shifted away from growing
the microgreens in a dedicated bed, and tried growing them as an infill crop among the other
plants instead.
This seemed to be quite a useful way to use the space after the successional harvesting
of early potatoes, which were only being harvested a few plants at a time.
As soon as enough space was available, I would rake the soil to produce a flat seedbed, sow
the seeds, cover with compost, water in, then then cover the seeds with a board for a few
days.
The microgreens seemed to grow quite well in this context, right beside the actively
growing potato plants, and it all seemed to work out reasonably well.
Because the very young microgreen plants would not have started to pull a lot of nutrients
out of the soil, I felt that there wouldn’t be many issues with competition, and this
seemed to be the case.
I just needed to make sure that there was enough soil moisture, and that they were far
enough away from the potatoes so that there wasn’t too much over shadowing.
And I needed be a little bit more careful when harvesting the adjacent potato plants.
Growing microgreens in this way, as a type of succession or infill planting to make use
of part of the bed while the rest of the crop was being harvested, I think has real value
in an intensive growing space like this.
There are of course some issues with growing microgreens, and perhaps the most significant
is the amount of seed that is required, and this can cause it to be quite expensive.
With the other crops that I have been growing in the gardens, the cost of the seed is usually
very low and typically insignificant compared to the amount of food that one seed can produce.
This isn’t the case with microgreens and one of the reasons that I was uneasy about
growing them in the first place was that it seemed a waste of the seed to harvest the
plant so young.
This is still bothers me a bit, and I'd definitely like to explore the possibilities of growing
my own microgreen seeds.
Some of the other issues that I came across included the expense of the growing medium
that I was buying in order to grow the microgreens in flats.
I can appreciate that for many market gardeners, the ease, convenience, and reduced risk of
buying in specially prepared growing medium for this is a big part of the process, and
definitely worth the cost.
For those of us growing at smaller scale, I think there's other options, and for me,
it seems to make more sense to grow microgreens directly in the soil of one of my gardens.
I have had some issues with mould, which apparently can be an issue with microgreens, and perhaps
it is harder to control when grown in the soil.
I have also occasionally had problems with seed germination and I wonder if this may
be due to a build up of disease organisms in the soil, or that the decomposition of
the remains of previous crop may be causing some of these problems.
And I wonder what kind of issues would develop if I was to continue to grow a succession
of microgreen crops in the same bed for a long period of time.
Growing them as a scattered and an occasional crop between other vegetables is an option
that seems to work well, though it can make it more difficult to plan and to maintain
a consistent supply.
But making use of these small spaces in the garden combined with occasional growing in
flats, may be a useful combination for small scale production, or for somebody growing
just for themselves.
Another issue that i had from while in the polytunnel, was that mice kept eating a lot
of the sunflower seeds, and making a mess by burrowing out of sight under the cover
board.
This was a hassle, and I tried a number of different methods to get rid them or to deter
them, and ended up reverting to sowing sunflowers in flats again for a while.
Then I realised that I had typically spread seeds right up to the edge of the cover board,
and sometimes beyond, which made it far too easy for the mice to locate the crop.
I found that if I didn’t let any sunflower seeds come close to the edge of the cover
board when I was sowing them, this seemed to prevent the mice from being able to find
the seeds.
This was a really simple solution to a tricky problem, and it’s worked so far.
Overall I'm quite impressed with the possibilities of growing microgreens, and with how productive
they can be.
I've found them to be very useful when other crops are not so available, whether this is
due to poor planning on my part, or some disease or pest issues, or because of natural variations
in the seasons.
If I feel there might be a gap coming up in what I can harvest from the gardens, or if
there is limited variety available, then sowing a range of microgreens can really help.
I think that this is perhaps the greatest value for people growing food for themselves,
and to share with neighbours, as well as for community farms and market gardeners.
Microgreens can help make it easier to be self sufficient in vegetables throughout the
full year, or at least in this climate.
And I didn’t expect to see microgreens as part of developing the resilience of our food
supply systems, especially for those of use who grow our own food.
Assuming that I can continue to buy seed at a reasonable price, or to grow enough of my
own, then microgreens can be a way to quickly supply nutritious greens when problems develop,
or if disaster strikes.
I also think that microgreens can be a really valuable way to learn how to grow, or to begin
to grow your own vegetables.
The really quick time between sowing and harvesting means that we can learn a lot faster and explore
a lot of different possibilities in a short time and in a small space.
This is something that could take years and a lot of effort and space with conventional
crops in a garden.
And this is perhaps one of the most interesting benefits of growing microgreens.