Yes, Outredgeous Lettuce and Not Outrageous Lettuce
Do you like the play on words with the naming of Outredgeous lettuce?
Look at that lettuce; if that isn't an outrageous red, then I'm not sure what is.
Outredgeous lettuce, when mature, is a loose head type of romaine lettuce. There's a picture of one near mature from our garden later on in this article. But Outredgeous lettuce also makes a beautiful baby leaf green for salads and toppings for tacos, nachos, etc.
The story behind Outredgeous lettuce is fascinating, and we'll talk about that later in the article. We also discuss the nutritional value of red leaf lettuce.
First, we want to explain how we get such a deep red color on our red leaf lettuces.

Outredgeous Lettuce 23-days after planting starting to turn dark red. Red leaf lettuce starts out green and gradually turns redder as it grows if under the correct light conditions.
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How to Turn Red Leaf Lettuce Redder
If you've read any of my microgreens articles, you know that I often state that the type of LED light you use doesn't matter as long as the color temperature is over 5,000K. Here's a link to the lights I use for most of my microgreens.
However, to turn lettuces like Outredgeous lettuce and Ruby Red Leaf Lettuce red requires more power than LED shop lights can produce.
The tray of Outredgeous lettuce shown in this article is grown under a Mars Hydro SP150 LED light. We grow up to four trays under the SP150, though as you will see, the light coverage is a bit small for a 2- by 4-foot area without a grow tent.
The TSL 2000 or the SP3000 would be better for my grow area. Currently, we are working with vendors for trial lights to do reviews.
That said, the SP150 does a good enough job at a reasonable price to grow red lead lettuce. There will be more information about lights and how to set them up later in the article.
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How to Grow Outredgeous Lettuce
We grow lettuce a bit differently than microgreens.
The two reasons for this is that we are growing baby leaf lettuce to a larger size than microgreens. Therefore, each plant is going to take up more room in the tray. So dumping a boatload of seed on the soil isn't going to work out too well.
The leaves in the middle of the tray will brown out due to the lack of light.
The second reason is that lettuce seeds need access to some light to germinate. For that reason, we use a clear dome to allow light to reach the seeds and to retain humidity around the seeds sitting on the soil surface.
The Steps to Planting Lettuce Indoors
Below is a video of how I plant lettuce and grow it indoors. The lettuce grown in the video is Ruby Red leaf lettuce, but the same process and amount of seed sown is the same for Outredgeous lettuce.
Photos and text below the video specifically discuss growing Outredgeous lettuce.
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As I mentioned, the same planting process is followed with Outredgeous lettuce. Let's take a look at the growth stages of Outredgeous lettuce.
Outredgeous Lettuce Seeds
Lettuce seeds, for the most part, look similar, Below is a photo of 0.8-grams of lettuce seeds.

In the tray is 0.8-grams of lettuce seeds.
We sell Outredgeous lettuce seeds in the Home Microgreens Store. These are certified organic seeds, and we use them not only for growing indoors but also in the garden.

Besides microgreen seeds, the Home Microgreens Store also sells lettuce seeds to grow inside to baby leaf size or grow them up and transplant them in the garden.
You may be thinking that 0.8-grams of seed can't be enough for a 1020 tray. But we really believe that 0.6-grams of seed would be better because these plants will grow into baby leaf sized plants, and crowding is an issue.

As you can see in the photo, the seeds are spread quite thinly. Try your best to evenly space the seeds for the best results. You can click the image to expand the view.
What to Do Before Planting Lettuce Seeds
Good soil makes all the difference. We recommend our own soil blend or Fox Farms Coco Loco.
Wet the upper 1/3 of the soil profile. There's no need to wet all of the soil in the tray. We use a spray bottle exactly like in the video. We also mist the seed after sowing it.
After the plants start to grow, and the humidity dome is removed, we start bottom watering the lettuce tray.
The heavy-duty trays we use come from Bootstrap Farmer. We love these trays for their strength and durability. Check them out here.
Light Placement for Starting Lettuce Seeds
When we start lettuce seeds, we place the light slightly higher than later when the plants begin to grow. As you can see in the second photo. It's about 2-feet above the top of the dome.
Lettuce seeds need light, but not intense light at this stage.


This is the advantage of the SP150. The ratchets make adjusting the light height much more manageable. We grow out lettuce on a 2- by 4-foot shelf that can hold four trays.
This way, we can have lettuce growing in all stages for a constant supply even during the darkest and coldest central New York days.
Germination and Seeding Care for Outredgeous Lettuce
Lettuce germinates at varying rates depending on light, temperature, moisture, and variety.
Our Outredgeous lettuce started germinating in less than 2-days. We didn't record temperatures, but it was cooler outside, though the house may have been in the low 70's.


Notice the moisture in the dome. Usually, the moisture condenses and falls back onto the soil. But in some cases, such as when the shelf isn't level, soil moisture levels can fluctuate.
If part of your lettuce tray looks on the dry side, use a spray bottle, and mist the soil. Usually, you can tell dry areas as the soil is a lighter brown on color.
At this point, keep the dome on the tray, and the light elevated 18- to 24-inches above the tray if possible.
We run our lights 15 to 16 hours per day.
After 4-days
After four or five days, the lettuce starts to form a stem, and the leaves are getting much bigger.

We decided to keep the dome back on at this point and carefully mist the lettuce seedlings. The lighter the mist, the better, but don't worry if the plants' tip over. They will straighten back up unless you blasted them out of the soil.
We Use These Microgreen Trays
We use Bootstrap Farmer Shallow Heavy-duty trays when we plant 1010 or 1020 trays. We also use their deeper trays to plant peas or other uses.
These trays will never be damaged with normal use.
When we grow microgreens for ourselves we use the Home Microgreens Trays & Soil. We like the amount of microgreens these trays grow and we find we can either stagger plantings or double up trays to fit our microgreen needs.
Start Bottom Watering
When the lettuce seedlings are at this height, we start to water the tray from the bottom. Simply remove the planting tray or lift one end and pour in about 2-cups of water into the bottom tray.
When you lower the planting tray, the water is forced upward into the coconut coir soil base and absorbed.
We check moisture levels daily. At this point, you may need water every other day or so. But once the plants get larger, you'll need to water almost every day.
One Week After Planting
The dome can come off the Outredgeous lettuce tray a week after planting. Don't take that too literally; sometime between six and eight days is sufficient.


At this point, you can really see how well you spread the seeds. In our tray, there are a few light areas and some denser. It's ok; they will either grow to fill or push the outside plants outward. But again, the more evenly spaced you can sow the seed, the better.
In the close-up, you can still see the seed husk attached to the cotyledons. The red color will not show until the first true leaves form.
The fuzzy white hairs on the plants at the soil surface are root hairs and not a fungus. You can click the image and expand it for better viewing.
Now we lower the light to about 12-inches above the top of the lettuce seedlings.
What A Difference A Day Makes
The lettuce in the previous photos is 7-days old. The picture below is the following day.


The first true leaves start to grow, and you can see they are tinged reddish-brown. They will stay more or less this color for the next week to 10-days before the deep red color starts to show.
Outredgeous Lettuce on Day 15
As the lettuce continues to grow, check daily or every other day if the tray needs water and keep the light about 12-inches above the lettuce.
Sometimes, we raise the light higher to get better coverage when we have four trays on the shelf. The lettuce grows well, but the color will be a bit less bright.
Don't put any light that puts off some heat too close to the lettuce as the leaves may burn or curl up on the edges.
Here's our Outredgeous lettuce 15-days after planting.


You can see the lettuce has filled in the spaces and the leaf size is larger.
If you wanted, this lettuce could be harvested. However, we usually wait another week as the lettuce will start to color up even more.
Color Improvement Day 23 - Ready to Harvest
See the color improvement after 8 more days?


Also, notice there are more intensely colored red leaves on the left side of the tray.
This is because that side is more directly under the light. Light intensity is key to increasing the red color of the leaves.
This is also why when you move the outside leaves away, the lettuce is more green inside.
The lettuce is ready to harvest.
Use a very sharp knife or a pair of scissors to harvest the amount you want for your salads. Cut what you want and leave the rest to continue growing.
Can You Get More Than One Cutting of Lettuce?
Yes!
Cut the lettuce about 3/4-inches above the soil surface, and the lettuce will regrow. See the photo below.

The right side of this tray has been harvested and has started to re-grow.
It's possible to get 3 cuttings from one tray. However, it gets harder to keep watered as the tray becomes more root bound, and the lettuce will get slightly more bitter.
That's How Simple It Is!
Follow the directions in the video and this post, and you'll have lettuce ready in as little as 23-days!
We also published another article on growing Ruby Red Leaf Lettuce. Click this link to read that article.
Both Outredgeous and Ruby Red lettuce seeds can be purchased in the Home Microgreens Store. Enter "lettuce" into the search bar, and both will come up.

Home Microgreens Store
All the supplies and microgreen seeds you need to grow beautiful and nutritious microgreens at home!
Our prices are as competitive as the larger seed sellers. We also have our own soil, microgreen kits, and trays!
Some Interesting Outredgeous Lettuce Facts
Outredgeous lettuce is the first vegetable to be grown and eaten in space! It grew on the International Space Station in 2015! You can read more about it in these two articles:
Veggie Plant Growth System Activated on International Space Station
Meals Ready to Eat: Expedition 44 Crew Members Sample Leafy Greens Grown on Space Station
Why Eating Fresh Cut Lettuce is Important
The white milky sap that comes out of fresh-cut lettuce is where most of the lettuce nutrients exist.
The white fluid is called Lactucarium or "milky extract." The edible lettuce's genus and species are Lactuca sativa, named after the milky extract that flows from fresh-cut lettuce.
Usually, within 24-hours of harvest, the sap has deteriorated, as have the nutrients within it.
This is why freshly cut lettuce tastes better and is better for you!
For more information on the nutritional value of red leaf lettuce, read this article.
If you have any questions, please leave a comment below, and we'll find you the answer.