Nasturtium microgreens remind me of the Ugly Duckling fairy tale.
I’ve never seen such an awkward and misshapen seedling grow into a beautiful microgreen like a tray of nasturtiums.
Nasturtium microgreens start as stringy white seedlings and turn into gorgeous purple-tinted large-leaved microgreens. A true ugly duckling turning into a beautiful swan.
How to Grow Nasturtium Microgreens
Not only am I going to show you one way how to grow nasturtium microgreens, but I’ll also show you two different methods to germinate nasturtium seeds and grow them into microgreens.
Before we get into the details of growing nasturtiums, let’s discuss how these uncommon microgreens taste and how you can use them.
Nasturtiums: Not Your Average Microgreen
Most people recognize microgreens as tiny seedlings growing tightly in a tray. While nasturtiums eventually fill out a tray, they are seeded more sparely than most because the end product has much larger leaves.
You harvest nasturtium microgreens when the leaves are between 3/4-inch and 2 inches across and quite tall for microgreens as they will reach up to 5 or 6 inches tall.
Nasturtium leaves are similar to sunflower shoots. However, the leaves are more round and more extensive.
Like all microgreens, both the leaves and stems can be eaten raw.
The Flavor of Nasturtium Microgreens
The biggest surprise of nasturtium microgreens is their flavor profile. I heard they had a peppery, spicy bite, but the first time I tried my nasturtium microgreens, I was surprised by the sweetness of the leaf.
Then after the initial sweetness, the pepper bite and spiciness kicked in, making me glad I didn’t eat more than I did.
It wasn’t a mustard-like bite, not like wasabi mustard at all. Instead, it was sharp and more persistently spicy than any mustard microgreen I had tried before.
Nasturtiums are also reported to be very nutritious. I’ll touch on their health benefits later in the article.
How to Use Nasturtium Microgreens
Because of their spicy bite, using only a few nasturtium microgreens at a time is wise. They are not the kind of microgreen that you throw a handful on a salad. At least, I’m not going to go overboard with their use.
I chopped the leaves and stems so I could distribute the flavor.
All parts of the nasturtium above ground (stems, leaves, flowers) are edible.
My first use of nasturtiums went into street tacos. The first time with chicken tacos, I added the chopped nasturtium raw into the taco.
For the second batch of street tacos, I added the finely chopped nasturtiums right to the taco meat just before taking it off the heat.
I liked this method better. The spiciness was more thoroughly incorporated into each bit.
Dips, Guacamole, Salsa, Dressing
The next day I had a few people over to watch a football game. I added the raw, finely chopped nasturtium microgreens to guacamole and salsa. Both got compliments, and I didn’t tell them beforehand what was in the dips.
I will remember this and use nasturtiums in my guac when I don’t have fresh hot peppers. It added a fresh spiciness that wasn’t overwhelming. Also, there is no reason nasturtium microgreens couldn’t be used in any dip, salsa, or cream dressing where you want a kick.
Of course, I added nasturtiums to salads. Again, finely chopped to spread out the flavor.
You can also use nasturtium microgreens to add them to potato and macaroni salads, egg dishes like breakfast scrabbled, to dinner quiches.
They can flavor olive oil or be added to oil & vinegar salad dressings. I’ve even heard of them being used to flavor tea.
Growing Nasturtium Microgreens
Nasturtium seeds are large. Depending on the variety, up to a centimeter long.
I chose the nasturtium variety called Empress of India for a few reasons. Firstly, the seed size is on the smaller side, 5 to 6 millimeters.
Secondly, I liked the purple tinge to the leaves and the lavender-colored stems rather than a plain green leaf.
Lastly, the seed price is lower than the variety Jewel, which does have multi-colored flowers but plain leaves. The Empress of India has scarlet-colored flowers. Not that I plan on growing nasturtiums to the flowering stage in the house.
Maybe I’ll plant some in the garden next year; we shall see.
I digress; if you’ve read my how to germinate microgreen series, you know that I’ve documented that the weighted blackout method can be applied to all seeds. Furthermore, the buried blackout method is my preferred method to grow seeds, especially in smaller trays.
So why not show you both methods with nasturtiums, and then you can choose which method you want to use?
Empress Of India Nasturtium Seeds
The seeds of nasturtiums are relatively large as microgreen seeds go. They are oval with lightly colored longitudinal ridges and darker brown depressed areas. They are relatively dirty (a powder coating) and quite hard, similar to beet and chard seeds.
How Much Nasturtium Seeds per Tray?
Before I tell you my recommended seeding rate, I want to remind you that nasturtiums are spicy. You don’t need many microgreens to impact your food.
So unless you are planting nasturtium microgreens to sell, you only need to grow a small tray of these beautiful microgreens.
Of course, I planted my nasturtiums in Home Microgreens Trays. The trays have a planting area of between 37 and 38 square inches.
I prepared two sets of nasturtium seeds weighing 13.6 grams. A level Tablespoon weighs about 9.5 or 9.6 grams. It’s best to have measuring spoons with steep, almost vertical sides to measure microgreen seeds. Especially larger seeds.
My recommended seeding rate is 0.36 grams per square inch of planting area.
Soaking Nasturtium Seeds
Because the seeds are large and hard, it’s best to soak them before planting on or in a potting mix.
I poured some lukewarm water into two prep bowls and added my seeds.
I let the seeds soak for about 5 hours before planting. However, there is no reason you can’t soak them longer. Soaking them overnight would be good, or start the soak before you go to work, and you can plant them when you get home.
As mentioned, the seeds have a powdery coating, so the water is dirty. Therefore, I dumped the seed into a strainer and rinsed them after soaking.
Preparing Trays for Nasturtium Microgreens
I recommend you grow nasturtium on a potting mix.
Because of their nature, the nasturtium will not grow well on grow mats. I’m sure they will germinate, but a grow mat would not provide enough support for the plant because they grow large.
I prepared two trays of Home Microgreen Potting Mix for my sets of nasturtium seeds. One tray is filled near the upper lip for the weighted blackout.
The soil in the second tray was tamped and leveled with the soil surface about 1/4 inch from the top. The seeds that go into this tray will be germinated using the buried blackout method.
Once the soil is at the correct level and tamped, it is misted to wet the upper surface of the soil. There is no need to wet the soil to the bottom of the tray.
Why Did I Plant Two Trays of Nasturtium Microgreen Seeds?
You only have to plant your seeds using one method or the other. I’m explaining what I did. You can see my results and choose one of the methods.
I knew I could grow the nasturtiums using the true and tried weighted blackout method.
But I wanted to see if the buried method would produce a better product.
If you need to familiarize yourself with these two methods. You can click here to get more details on how the trays are prepared and what is involved with these two blackout period methods.
In the buried method article, I said I like to use that method with larger seeds because the seeds don’t dry out. With the weighted method, the larger seeds keep the tray separator raised above the soil. Allowing air to flow around the seeds on the edges of the tray.
The air dries out the seed, and the germination rate drops. Also, the plants around the edges of the trays grow smaller. This is more apparent when using smaller trays than 1010 or 1020 trays. But it still occurs to a lesser degree on large trays.
Planting the Nasturtium Microgreen Seeds
Spread the seeds as evenly as possible across the surface of the potting mix. There will be some space between the seeds.
This is okay.
The nasturtium microgreens will grow large and fill the tray.
My seeding recommendations are less dense than most, but the extra space allows all microgreens to grow to their potential. We are not growing these microgreens to sell. Instead, we are growing them for peak nutrition.
The majority of the nutritional value of microgreens is in the leaves, not the stems. We want larger leaves. Give all of your microgreens room to grow. They and you will be happier.
Once the seeds are on the potting mix surface, mist them with a sprayer to rewet the seeds.
My tray for the weighted blackout method is ready to go under the weight. With the buried tray, I covered the seeds with a layer of soil and misted them until I thought they were wet to the seed level.
You can see both trays below, ready to go into the blackout.
Buried method on the left. seeds are covered with a thin layer of soil. Weighted blackout method on the right. Both trays are ready for a tray separator to be placed on top and then weight.
Time Spent in the Buried and Weighted Blackout Period
The trays were set on my microgreen rack, a tray separator was placed on top, and then 2-1/2 pounds of weight was added to the top of each tray.
Both trays remain in the blackout period for the same amount of time.
Nasturtium seeds start germinating after 4 days. However, they remained in the blackout for a total of 7 days.
On the fifth day, the trays were misted to rewet the soil. The tray in the buried method was likely ok. That is the advantage of using that method, as the soil retains moisture. But I wet the soil regardless.
The photo below shows the seeds’ progress and differences in how the plants emerge from the seed and soil.
Check on the seeds on the fourth or fifth day. Then recheck them on the seventh day to see if they are ready to go under lights.
Day 4 of Nasturtium Germination
Trays are reversed compared to last photo. Weighted method on the left. Buried method on the right with the tray separator off.
You can see the nasturtium seeds have started to germinate. Therefore, one would have to expect that the seeds in the buried method (right tray) germinated, but we have yet to see them.
Notice how the soil around the edges of the left tray (weighted blackout method) is lighter brown and dry. While all of the soil in the buried method is much darker and wetter.
The larger seeds lift the tray separator allowing air circulation to dry out the soil. This is why I misted the tray on this day.
I could solve that problem by lowering the soil level, so the separator rests tightly on the tray top. But this would take soil away from the plants as they mature and make them less supported.
Below is a close-up of the weighted method tray. You can see the root hairs on the nasturtium radicle.
Nasturtium seeds start germinating on day 4.
Day 6 of Nasturtium Germination
Plants start emerging from the buried blackout method tray on the sixth day.
Nasturtiums start emerging from the soil in the buried blackout method tray on day 6 (right tray).
Day 7 Nasturtium Germination – Ugly Ducklings
After spending one more day in the blackout period, it’s time to put these nasturtium microgreens under the lights. They don’t look like much, but it’s time.
Weighted blackout method on the left. Buried blackout method on the right.
Remember, at the beginning of the article, I called young nasturtium microgreens ugly ducklings. So you can see why I called them ugly.
Again, the weighted blackout method tray on the left is quite dry. While the buried method tray looks better.
Time to Water From the Bottom
Now is the time to water these microgreens from the bottom. It wouldn’t hurt to mist them one more time over the top at this stage. The soil in the left tray is quite dry.
The Home Microgreen Tray and the 1010 and 1020 trays have a significant advantage over the other methods I see people using.
The planting tray fits snuggly in the watering tray. So when you add water to the bottom tray and lower the planting tray, it forces water into the holes in the bottom.
The plants don’t have to grow down to the water like they do in those green and white sprouting trays.
Another advantage is you can’t overwater the trays. If you add too much water, it spills over the top of the watering tray. It is only possible to over-water microgreens using these trays if you water them daily.
Don’t do that. The potting mix can hold enough water for 2 or 3 days.
You can read my article titled How to Water Microgreens to see how much water to use each time you water.
Nasturtium Microgreens Under Lights
I choose the grow lights instead of my shop light setup mainly because that is where I take most of my photos. But also because I knew Empress of India Nasturtium leaves had some purple highlights on the leaves. Also, grow lights will produce more colorful microgreen leaves than shop lights.
I discuss the pros and cons of grow lights and shop lights in Episode 26 of the Microgreens Podcast. In the podcast show notes, I list links to my favorite lights for microgreens.
I didn’t grab a photo of the nasturtiums after the first day under the lights, but below is one on the second day. Making it nine days after planting the nasturtium seeds.
They still don’t look like much, do they?
However, they start growing quicker from here on out, depending on the room’s temperature.
Nasturtium Microgreens Ready For Harvest
On day 12, the nasturtium microgreens are ready to harvest!
The stems have elongated and colored up, and the leaves have grown in size too. For scale, the height of the Home Microgreens Tray is 2 inches tall.
Which Method Grew Nasturtium Microgreens Better?
It’s a toss-up. Both trays look very similar and have the exact yield.
However, the buried method required much less maintenance and worry while growing these microgreens. In addition, the soil stayed more evenly wet, and even though I misted the seeds during the blackout period, it wasn’t necessary.
Buried blackout method for the win when planting large seeded microgreens varieties.
Another Nice Thing About Nasturtium Microgreens
I enjoy growing nasturtiums.
The seeds are different than most microgreens. The germination process is enjoyable, watching the odd-shaped seedlings grow and unfurl their leaves. The quick spurt of growth once the leaves form.
And let’s not forget their unique flavor and spicy bite.
But one of the best attributes of nasturtium microgreens is the time the microgreens can grow in the tray. If you water them, they will keep growing in the tray.
In other words, the leaves have the same flavor regardless of age. Many microgreens have what I call a short harvest window. They must be used before they become bitter or tough, or the flavor changes and becomes inedible.
Not so with nasturtiums; the leaves have the same flavor. Sure, the lower stems become woodier, but you have more than enough leaves to eat by then.
In fact, I know some people that grow nasturtiums in the garden, enjoy the flowers, yet still harvest leaves to use in the kitchen.
If you want to purchase nasturtium seeds to grow as microgreens, the Home Microgreens Store carries them in a few different size packets and bags.
Nasturtium Microgreen Health Benefits
Nasturtium microgreens are reported to have high levels of vitamin A precursors (beta-carotene), vitamin A, manganese, and iron.
Nasturtiums also contain the highest concentration of lutein of any plant. Lutein is helpful for eye health.
Nasturtiums are a traditional medicine go-to for colds and sore throats. In addition, the young leaves can be applied to wounds as an anti-bacterial treatment.
Nasturtiums and teas made from nasturtiums are used to treat chest congestion and sinus problems. The main types of chest infections are bronchitis and pneumonia.
I haven’t made nasturtium tea, but Living Healthy Herbs says to put 3 or 4 bruised leaves in a cup, add boiling water, steep for 15 minutes, strain out the leaves, and you have tea.
Because bronchitis is viral, nasturtium’s anti-bacterial properties won’t help. However, pneumonia-type infections are bacterial, and nasturtium concoctions may help.
In South America, the Inca use nasturtium leaves as an herbal cleanser, diuretic, and sterilizer to help reduce chest congestion symptoms and wound care.
Nasturtiums may be beneficial in reducing hair loss and helping clear up acne.
How to Grow Nasturtium Microgreens Summary
Here is a summary of the article. Details are found in the article.
- Nasturtium microgreens grow best on soil.
- I recommend using 0.36 grams of seed per square inch of tray. This may change for larger trays.
- A level (vertical-sided) tablespoon weighs ~9.5 grams.
- You don’t need many nasturtium microgreens to increase flavor – a small tray should be enough.
- The buried blackout method is my preferred way to grow nasturtium microgreens.
- The blackout period is more extended than most. It could last up to seven days.
- Once under lights, the microgreens grow faster.
- You can start harvesting nasturtium microgreens in 12 to 14 days.
- Nasturtiums will grow in a tray much longer than most microgreens.
- There are many ways to use nasturtiums in the kitchen.
There you have it. You should give Nasturtium microgreens a try. They are fun to grow, beautiful, nutritious, and tasty!
Do You Have a Pinterest Microgreen Board?
If not, why not start one? Use this pin as the first, or add it to your existing boards.