Growing Mustard Microgreens: How to Grow Beautiful Red Lace Mustard

We have published quite a few articles on growing mustard microgreens. The reason is we keep finding cool ones to grow.

We have Wasabi Mustard, one of the spiciest (we might be getting in an even spicer one! Fingers crossed) microgreens.

Then there’s a similar Wasabina Mustard, not as spicy as Wasabi but close enough, and the organic seed is less expensive than Wasabi.

Let’s not forget about Red Garnet Mustard, which we thought had the reddest cotyledons around (until now).

This article will showcase our newest and reddish mustard yet! It’s called Red Lace Mustard, the deepest maroon color we’ve seen. As good of color as Rambo Radish.

Growing mustard microgreens is easy, and there are multiple ways to grow them.

Check it out. 

Growing Mustard Microgreens Two Different Ways

We grow mustard microgreens using two different blackout methods. The method most commonly utilized by microgreen growers is the weighted blackout method.

Another tray covers the seeds, and weight is added to the top to create better seed-to-soil contact.

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Then there is the domed method, where another tray is placed upside down over the planted tray.

The domed method is used when the microgreens have thin stems or when temperatures in the growing area are warm.

The domed method is on the left. The weight is used to hold the tray in place when a towel is draped over both sets of trays. The weighted method is on the right. For small trays, we use 2-1/2 to 5 pounds. We use up to 10 to 15 pounds of weight for larger trays.

How to Choose Between the Weighted or Domed Blackout Method?

As mentioned above, the weighted method will work with any microgreen.

So why even talk about the domed method? 

Because some microgreen varieties do better without the added pressure on their thin stems.

I also use the domed method when the temperatures are hot and if I have soil that is still working (composting – yes, I’ve had commercial potting mixes still composting when I receive it).

But the domed method has drawbacks too.

You will see a couple in this article. 

So how do you choose?

You read Home Microgreens articles because we do the testing for you! This article will show you. 

Or, you plant two small trays and test which works better for you. 

Growing Mustard Microgreens – Red Lace Mustard as an Example

We planted two Home Microgreens Trays filled with our potting mix with 2.0-grams Red Lace Mustard Microgreen seeds.

In this article, we won’t go over how we prepare the trays for seed. You can read how we do that in the Red Garnet Mustard article or get your Home Microgreens Quick Guide copy.

We placed the trays into blackout, one using the weighted method and the other the domed method, and didn’t look at them for three days.

Removing Trays From Blackout and Under the Lights

Three days is more than enough time for the seeds to germinate and the seedlings to search for a way out of their confinement. If you have a warm room, say 75 degrees F or above, most likely, they will be ready in two days.

When the mustard microgreens look like the ones below or reach the top of the blackout dome, it’s time to put them under lights.

You can see mustard microgreens pushing against the lid. We like the opaque lid because we can see the growth without disturbing the seeds if they aren’t ready to come out of the blackout.

Differences Between the Domed & Weighted Blackout Methods

One of the most observable differences between growing mustard microgreens using the domed and weighted methods is how they look once they have germinated. 

Microgreens under the domes method are taller, and the roots haven’t anchored into the soil. 

The left tray (below) is the domed method. All that white you see isn’t mold; those are root hairs. 

The roots are more visible in the domed method because they haven’t had to fight any weight. So there is no need for them to anchor deeply. The air is more humid under the dome, so the roots can get water from the air instead of the soil. 

The left tray is grown under the domed method. The right tray is under the weighted method. The white is not mold. Those are root hairs. The text explains why there are so many in the domed method.

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Close-up of the root hairs.

We watered both trays from the bottom – the Free Guide shows this step – and placed them under two 24-watt LED grow lights from Barrina. 

These lights are working wonders for our microgreens. We will publish a blog on them soon. 

The Differences Are Amazing

We have never seen such a difference between growing method as in the following photos. 

We have seen microgreens grown under the dome be much taller and straggly. But never such a delay in color.

Under the Lights They Go

If I didn’t grow them, I’m not sure I’d believe the difference in these microgreens. 

Believe it or not, these are the same microgreens after 2-days under the lights.

The left tray is the Red Lace Mustard grown by the weighted method, and the right tray was germinated under the domed method.   

The weighted method has already turned a deep burgundy red and grown only slightly. While the domed method is only starting to turn color and has grown like a weed.

One wouldn’t even think they are the same microgreen!

The Red Lace Mustard microgreens in that photo are five days old (from seed).

Below are close-ups. Click the image (or any in the article) to expand the photo for better viewing. 

Grown using the weighted method.

Grown using the domed method. Both trays are the same age.

Red Lace Mustard Microgreens 6-days After Planting

From this point on, growing mustard microgreens is very easy. Ensure they aren’t dry or overwet and will grow for you.

After one more day, the mustard microgreens grown under the dome have added a bit of color, while the other tray has decided to grow and catch up to their sibling tray.

The only question is whether the Red Lace Mustard on the right will turn as deep maroon as the left tray. 

We Love the Color and Compactness of the Weighted Tray

The following photos are of trays 11- and 15-days after planting.

The key point of these days is that the microgreens are ready to be harvested on about day eleven, and the color on the mustard microgreens grown under the dome is now about the same color.

Red Lace Microgreens 11 days after planting.

On day-15, true leaves formed on both Red Lace Microgreens trays. 

Red Lace Mustard microgreens 15 days after planting. True leaves are starting to form.

Red Lace Mustard Microgreen True Leaves

As mentioned, on day 11, the microgreens were ready to be harvested. But mustards have different flavor profiles as they grow.

For example, many people like the stronger flavor of mustard microgreens once the first true leaves form.

True leaves start to form around day-15.

Another reason, if one is inclined to plate their food instead of plopping it on their plate as I do, is that Red Lace Mustard has a lovely true leaf.

However, it is smaller than the true leaf on Red Garnet Mustard and much more serrated, almost like a cut-leaf Japanese maple leaf.

Red Lace Mustard Microgreen Flavor – How to Harvest

I like mustard microgreens when they are younger, with no true leaves. But you will have to try them as they grow to figure out your favorite.

We harvest our mustards when they reach almost 3 inches tall. Then, using either a sharp knife or a pair of stainless steel scissors, we tip the tray about 45 degrees and cut the stems above the soil’s surface.

We cut what we will use and let the rest keep growing. 

Mustard microgreens will not grow back when cut this low. 

The flavor of Red Lace Mustard microgreens is much milder than any other mustards we have grown. However, many websites say they are spicy.

We do not concur if you want spicy grow Wasabi, Wasabina, or Southern Giant mustard for microgreens. They have a punch.

The Home Microgreens Store sells all of these (and more) mustard microgreen seeds in various packet sizes. 

Summary & Recommendations for Growing Mustard Microgreens

Growing mustard microgreens is easy, regardless of the method you use. 

For Red Lace Mustard, we recommend growing them using the weighted blackout method. 

You will find that the microgreens are sturdier, color up sooner, have a denser habit, and reach the same height as those grown under a dome.

If you need the microgreens sooner than later, use the domed method. They grow taller quicker. Also, if the area you grow microgreens is hot, say in summer, it’s best to grow them with the domed method.

You have seen the photos so that you can choose your desired method. But by all means, grow Red Lace Mustard.

Growing mustard microgreens is fun, and Red Lace Mustard is beautiful to look at during all stages of growth. Red mustard microgreens are nutritious, rich in vitamins A, C, and K, and antioxidants, with anti-inflammatory and natural detoxifying properties. Some sources also report that they contain compounds with cancer-preventing benefits.

Red Lace Mustard Microgreens will not disappoint you. Give them a try!