Are you pulling your hair out trying to grow microgreens? Maybe you’re trying to grow harder varieties. Or maybe you’re just missing the trick that makes it all work.
The hardest to grow microgreens typically have slower growth, small seeds, thin stems, inconsistent germination, hard-to-source seeds, low available information, seed hulls that don’t shed on their own or a combination of these factors.
Microgreens that are commonly considered hard to grow include:
Keep reading to get to the bottom of why these microgreens can be so challenging, and unlock the secrets to success.
What makes a microgreens hard to grow?
Microgreens can be hard to grow because of:
- Slower growth
- Little available information
- Mucilaginous seeds
- Small seeds and thin stems
- Inconsistent germination
- Hard to source seeds
There is usually a way to work around each of these issues.
Keep reading for a dive into some ways you can grow the more exotic microgreens. They open up a world of possibilities (for your cooking at home, or to sell).
If a microgreen is hard to grow, it means you have less competition if you’re interested in selling it.
Information can be another reason microgreens can be difficult to grow. The less popular varieties have a lot less information available online. Not knowing what to expect: seeding densities, timelines, whether soaking or blackout are necessary. The lack of information can really increase difficulty.
Pre-soaking to help even germination can be necessary. And it’s really tricky to grow a seed that needs pre-soaking without it.
Chia, flax, basil and amaranth are popular examples of mucilaginous microgreen seeds.
Mucilaginous microgreens need to be grown slightly differently than a lot of other microgreens.
They benefits from a blackout period, but unlike more robust microgreens, stacking trays during the blackout period results in stunted growth.
You can find out more about the typical microgreens growing steps in my step by step guide, it’s the blackout step that needs to be modified.
The modification: instead of pressing down the seeds with another tray on top, give them room to grow by flipping the tray upside down. You’re creating a humidity dome with the second tray, but it’s blacked out instead of transparent.
Smaller seeds can germinate unevenly because they dry out so quickly. A smaller seed can’t hold as much water, and doesn’t have as much surface area in contact with the soil.
Small seeds and thin stems
Broccoli is a very commonly grown microgreen with tiny seeds and really thin stems. One of the big problems with the really thin stemmed microgreens is that they have moisture problems.
They’re not very tolerant of drying out (they start to shrivel up easily), but they also aren’t tolerant of high moisture levels. The thin stems and close spacing needed to get decent yields can result in mold problems.
If the humidity in your grow space is too high, and you’re having mold issues, consider a dehumidifier. You can find equipment recommendations on my supplies and equipment page. I update it every time I find a better piece of equipment to get the job done.
You can also consider fans to move the air around. Humidity will be highest near the microgreens because they’re release moisture into the air as they photosynthesize, the soil is also evaporating water.
If you’re having problems with microgreens falling over & wilting, consider watering more frequently, and also consider planting more densely. Planting more densely restricts airflow and holds in moisture, but again, too dense and you can have mold problems.
Inconsistent microgreen germination is usually due to one of the following factors:
- Not soaking the seeds. Not all microgreens need to be soaked, but microgreens with larger seeds like pea or sunflower germinate much more consistently after a good soaking.
- Blackout period. The blackout period traps in moisture, and slows down growth, giving the slower seeds time to catch up.
- Old seeds. Older seeds have lower and slower germination.
It might seem like it’s in a plant’s best interest to germinate quickly.
Let’s think through what could happen in nature.
Imagine if all the seeds of a species germinate quickly, then there’s a heavy frost. Or a disease spreads across them. If everything germinated and was wiped out, the species is in serious trouble.
To counteract this, most plants have genetic diversity that cause faster and slower germination to stay in the mix. This way there are always some late-bloomers to save the day if something goes wrong early.
Hard to source microgreens
Some microgreens are harder to source than others. They might sell out quickly, or they’re just so rare that they’re hard to reliably find.
Harder to source microgreens are the ones that are less frequently grown, but they can also be microgreens that are harder to grow. Harder to grow mean less demand, means less reason to have them in stock.
I’ve noticed that in the early part of 2020, Kale microgreens have been harder to source from some large seed suppliers. In this case it’s not because they’re rare, but the opposite! Demand is higher than supply, so they’ve temporarily run out.
Slowest-Growing Vegetable, Herb and Flower Microgreens
Microgreens that take longer to grow are more prone to disease pressure. Some microgreens sprout and grow quickly, outpacing most fungi and bacteria.
For the slower growing ones there’s more time for problems to set-in, so you need to control temperature and humidity that much tighter.
Here are some common examples of slow growing herb microgreens:
- Cutting Celery
- Lemon Balm
Grain and vegetable microgreens can be slow growing as well, here are some examples:
Johnny seeds does a ton of testing, and they put together a chart of slow-growing microgreens.
Most Difficult microgreens to grow
Many vegetables, herbs, and flowers can be grown as microgreens. Here’s we’ll focus on the more popular varieties that are difficult, as they list can get really long.
It’s hard to put together an objective list of which microgreens are most difficult because your experience, your conditions (temperature and humidity), and the quality of seeds available to you will all have a huge impact.
But here it is.
The 6 most difficult Microgreens, and Why
Top tip: Sub-irrigate or mist instead of watering from the top. This will stop the tiny seeds from moving around and clumping together.
Amaranth tends to be a challenging microgreens. Uneven germination from the mucilaginous seeds and tiny stems can be conttiny
mucilaginous seeds, thin stems, uneven germination
Top tip: Let me know if you figure out a consistent way to grow these! I’m still working on it.
Chives & garlic chive microgreens get off to a slower start than a lot of microgreens. They also have short storage life.
“A slow grower and more challenging”
They only store for around 5 days, maximum a week. That’s one of the biggest challenges with chive microgreens, especially if you intend to sell them. You need to get them into the hands of your customers on an expedited timeline.
This can also present an opportunity in the market. The larger food distributors with their slower supply chains won’t be able to get chive microgreens to chefs and other customers with enough shelf-life left. But you can!
Beets & Chard
Top tip: pay special attention to humidity and watering schedule before harvesting, to soften up the seed hulls, consider a humidity dome to soften up the hulls so you can brush them off pre-harvest.
A big challenge with beets and chard isn’t so much the growing, but removing the seeds. Whether you’re growing them for yourself, or to sell, you’ll have some work cut out for you figure out how to deal with the tiny seed hulls.
Top tip: spread the seeds as evenly as possible.
Basil has mucilaginous seeds. Tiny seeds that develop a gel-like substance around them. There are a lot of ways you can go down the wrong path with mucilaginous seeds.
Mucilaginous seeds are also believed to release phyto-toxins. This means as the seeds germinate they slow or prevent the growth of nearby seeds, an evolutionary benefit, but a real challenge for microgreens!
Basil is also slower-growing, it can take 2-3 weeks to be ready for harvest.
Basil can be particularly attractive to insects. I’ve noticed on more than one occasion whiteflies somehow make their way towards Basil, and they’re a real pain to get rid of, fungus gnat can be a problem too (here’s how to get rid of them).
Top tip: germinate at slightly higher than room temperature (75 F or 24 C, use a heat mat if you must), then return to regular temperature (60 F or 16 C, just below room temperature)
Carrots are a bit unique because they have really small seeds, that have a long germination period.
Otherwise, grow similarly to brassica family microgreens, like broccoli or radish.
Getting into more complex-to-grow microgreens
The important thing with difficult microgreens is understanding exactly what the challenges are. The more you understand, the more easily you can succeed where others fail.
One of the best tips I can give when trying a new microgreen is to read the instructions. Your seed supplier will likely have a set of steps for growing your specific microgreens. Follow the steps and you should be just fine.
Some of the more complex microgreens are really rewarding. Amaranth has beautiful deep reds and pinks. And some microgreens have interesting fine textures, like chives.
Easiest Microgreens to Grow
The easiest microgreens to grow are radish, broccoli, sunflower (don’t forget to soak for 8-24 hours), and pea shoots (soak these too).
Radish and broccoli germinate really evenly and quickly.
Sunflower seeds and peas are large. So they store lots of energy and moisture once they’re hydrated. I find they’re more tolerant of under and over-watering as well.
Can you harvest microgreens more than once?
Some microgreen species can be harvested more than once, pea shoots are a great example of this. Sunflower, broccoli, and radish microgreens can only be harvested once.
I’m Alex Lafreniere. I learned a lot about plants when I built and operated a landscaping company. But, there’s always more to learn. Ever since travelling across the world, I’ve wanted to find ways to bring more tropical and exotic plants into my life. This is the site where I share everything I’ve learned with you.
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