That’s right, nasturtium microgreens are a thing. We know nasturtiums are a beautiful and edible flower that can add a peppery kick to salads. But you can also grow them specifically for their shoots and leaves.
Nasturtium microgreens (also called shoots) are a delicious addition to any dish, adding a unique spicy flavor and texture that is sure to impress.
This is particularly appealing to chefs who use it in a variety of ways for plate presentation. You don’t need to feel intimidated by the prospect of growing them for microgreens (shoots). With a little practice, you can grow them without any problems.
Are you nervous about trying to grow them? A lot of new growers are, but in this guide we will walk you through the steps of how to get a great yield of beautiful nasturtium microgreens. The main reason you will have success is getting the water levels just right.
So if you’re ready to learn how to grow nasturtiums for microgreens, read on.
Table of Contents
Always Soak the Seeds
To grow nasturtiums for shoots and get an even germination, it’s important to start with high-quality seeds. We recommend purchasing these seeds specifically for shoots from Johnny’s Seeds.
With those, you don’t need to “nick” or cut into the seeds to start germination. Remember, we’re not growing these into the flower stage. This is strictly for leaf growth.
Another option for nasturtium seeds is True Leaf Market.
Before planting the seeds, we always soak them for 2-4 hours using a mason jar and sprouting lid. They always come up more evenly in the soil when we do this.
Because we grow in individual, 5×5″ blocks from Bootstrap Farmer, we soak 165 grams of nasturtium seed. This spreads out over 8 blocks that fill one 1020 standard flat. You may need to soak more seeds if you are growing directly in a flat without using blocks.
With proper preparation, we begin to see the seeds germinate and emerge in 7-10 days.
Soil for Nasturtium Microgreens
Be sure to use a deep flat (about 2″) so that you have enough soil. The seeds are large and will require room for root growth.
After soaking, drain the water from the jar, rinse them once, and fill your tray. We use our own custom soil blend of peat moss, compost, and perlite, but any quality seedling soil mix that has an airy texture will work.
As you fill the flat (or 5×5 block inserts mentioned above), make sure to leave about a 1/4 inch of space from the top. This is important because you will need to cover the nasturtiums when you finish planting them.
Spread out the seeds evenly across the soil. Be sure there are enough to fill out as they grow but not so crowded that they will compete for space and stunt each other. The germination rate of nasturtiums is usually about 84%, so keep in mind that some seeds may not pop up.
When you’re done spreading them out, spray some water over the entire flat. Then take some more soil and fill it to the top. This is why we left some space when filling up. Once they’re covered, press the soil down lightly.
Transfer to a heat mat (if you have a thermostat control, set it to 74 degrees) and cover with a blackout dome. If you don’t have a blackout dome you can use heavy duty parchment paper that’s long enough to cover the edges and place an upside down 1020 flat on top.
Don’t be worried when it seems that nothing is happening. Keep the soil moist on top but don’t overdo it. Nasturtiums are flowers, which often take longer to pop out of the soil. An average germination time is 7 days even with a heat mat.
The first shoots will start to emerge and it will look like you’re going to get a spotty crop. Don’t panic! This is normal. More shoots will come out, I promise. We transfer our nasturtiums off the heat mat when there’s a decent amount of soil being pushed up, usually at day 8.
Leave the flat uncovered under your grow light and let the plants do their thing. The light encourages the new shoots and soon you’ll see a good crop of nasturtiums filling out the flat.
This is probably the hardest part of growing nasturtiums for microgreens. As a rule, they don’t like a ton of water. Yet, there has to be enough moisture to encourage the shoots to grow. So after you’ve put it under the light, give it a good bottom watering the next day.
Once you’ve given it a deep watering, only spray the roots enough the next few days to keep them from drying out. This is a balance that has to be mastered through practice. In another several days, you will probably need to give the flat another deeper watering.
You’ll see much better growth by not drenching them every single day. Nasturtium microgreens are very hardy and can survive dry soil. We made the mistake of not giving them enough water in the beginning and realized how dry the soil was. But they were growing and still looked fine with no sign of drooping.
Even if you don’t get it perfect the first time, just keep trying. You’ll get the hang of it soon.
Photo shows nasturtiums at day 10. Their growth intensifies quickly towards the later half of your growing cycle.
By day 16 the nasturtiums should be a tall and vibrant forest in your flat. They are ready to harvest or sell live at this point.
Uses and Flavor
Nasturtiums are not only beautiful to look at, but they also have a unique flavor that can add a spicy and peppery kick to any dish. Chefs love to use nasturtiums in culinary creations to add a pop of color and flavor, such as salmon.
The leaves, flowers, and stems of nasturtiums are all edible and can be used in a variety of ways. The leaves and flowers can be used as a garnish on salads, soups, and main dishes. The leaves are unique and truly add flair to a dish.
In terms of flavor, nasturtiums have a peppery and slightly bitter taste, similar to arugula. The flowers have a milder flavor and are often used in desserts or as a decorative element on cakes and pastries. For this article, we’re strictly focusing on the leaves as microgreens.
Nasturtiums can be a show-stopper and are popular with chefs. If you’re growing microgreens to sell, they are definitely worth perfecting for a restaurant market, but customers on the open market will probably find them appealing as well. Give it a try! It’s satisfying to conquer the challenge of growing nasturtium shoots.