This is a tried and true method to easily grow arugula microgreens at home. This guide shows you how to grow in smaller containers you probably already have in a cupboard.
It takes up little space and you can grow all year long. Grow several varieties at a time with this at home microgreens growing method! Plus, it only takes a few minutes a day! We’ll cover the steps to grow and everything you’ll need including coco coir, arugula seeds, the mister I use and love, and growing containers.
Why Should You Trust My At Home Arugula Microgreens Growing Method?
I was a full-time microgreens grower for over 7 years, I sold a kit before microgreens kits were even popular. I sold living trays for regular people to eat at home. This is not a guide to grow bulk microgreens by the pound. This is for regular people to grow for their personal consumption. You can see all the varieties I grew and sold for years. This guide explains how to grow just like I did for the farmer’s market.
What Are Arugula Microgreens?
Microgreens are edible immature plants with loads of flavor and packed with nutrients. Arugula Microgreens are intense and pack a big flavor punch. Read more about Micro Arugula, what they are, and how to eat them in this post.
How Long Does It Take To Grow Arugula Microgreens?
If the weather is warm (70- 100 degrees) your Arugula Microgreens should be ready in less than two weeks. If the weather is cold (55-65ish degrees) closer to three weeks. If the weather is even colder, you’ll need to grow them indoors and use a grow light (about two weeks).
What Is the Difficulty Level for Growing Arugula?
Arugula is fairly easy to grow. But, they also have a tendency to grow mold, and before you know it, the crop has died. Know that this can happen. It happens to everyone at one point. The trick is to replant and try again.
Gather Your Arugula Microgreens Growing Supplies
1. Microgreens Seeds
Purchase arugula microgreens or sprouting seeds from a reputable seed company that has designated the seeds as appropriate for growing microgreens or sprouts. (Read more about avoiding foodborne illness in my post about the difference between Sprouts and Microgreens). You’ll need about 3/4 of a teaspoon of seeds to grow in a small deli tray. I’ve used this company’s seeds and this company . Contaminated seeds are why so many illness outbreaks have occurred in sprouts (again, sprouts and microgreens are related but not the same).
2. Growing Trays
For growing at home, my favorite trays to grow microgreens are 8 oz transparent round deli containers. I prefer to use transparent trays so I can monitor the progress visually and see the health of the roots. You can purchase these trays in bulk on Amazon if you will be growing many trays at a time, or recycle food containers you already have (like that hummus container).
They don’t exactly need to be 8oz or round for that matter. But, 8oz is a very good size for individual consumption. It allows you to grow multiple varieties at once, each in its own tray. They are easily washable and fit in a standard dishwasher. They are readily available. Also, the round tray allows for even air distribution and airflow to minimize crop loss from mold.
3. Mister
A spray bottle with a fine mister and clean water, the kind you’d drink. If you are going to grow regularly, a pump garden sprayer is convenient. However, a small spray bottle or even the mister nozzle on your garden hose will work in a pinch.
4. Growing Medium (“Soil”)
I recommend Coco Coir to grow Arugula. Don’t waste your time trying to grow on a paper towel (future post on that). Growing mats are an option too. I don’t prefer growing mats because they can break easily and need more attention with watering (they dry out faster). Coco Coir can come compressed or already fluffed up. Compressed bricks are much easier to store and are more economical to purchase online. The most cost-effective is the 5kg size here (you can either rehydrate the entire brick, or chip off pieces as you go), or get the smaller compressed brick here, or buy even small pucks here (I use two of the 30 mm pucks per tray).
Read more about why I don’t grow in peat moss here.
A Warning About Growing Medium
There are several companies that sell microgreen specific growing mediums. Be alert. Any medium used to grow microgreens should absolutely not contain any animal-based manure. That includes earthworm castings and guano. Avoid any growing medium or microgreen soil that contains any animal by-products. If the soil says it has compost– that too may contain animal by-products. Why? Animal manure is known to contain various pathogens like e-coli and salmonella, which can make you sick. Because microgreens are consumed shortly after planting, it is very possible your microgreens can become contaminated too.
5. Topper
After sowing, your tray of microgreens will need a cover until they grow a stem. The cover minimizes evaporation, keeps the seeds from drying out, and provides a darker environment. You have two options: a small piece of cardboard or box to place on top of your tray, or a second tray placed directly on top of your seeds. With the cardboard, you will have to spritz your seeds twice a day; with the second tray on top, you can plant and ignore them for several days.
6. Sun or Grow Light
If you’ve got a sunny window or a place with indirect sunlight, that is all you need. If it is mid-winter, cold and there is little sun out, you’ll need a grow light or even a desk lamp. Read to the bottom to see my note on growing in colder conditions.
7. Measuring Cup and Teaspoons
½ cup measuring cup and ½ and ¼ teaspoons
8. Water
Microgreens must be grown in potable water (i.e. water that is not contaminated and is safe to drink straight). Use bottled water, or filtered and boiled water if you must.
How To Grow Arugula Microgreens in Soil
Step 1: Prepare and Sanitize
Wash your hands thoroughly. Sanitize all surfaces. Wash all growing supplies (trays, measuring spoons, measuring cups) with hot soapy water and dry. Sanitize next. This is especially important if you are planting and growing in your kitchen. Kitchens tend to have various pathogens lurking about (it’s gross but you definitely do not want to pick up any pathogens and start growing them along with your microgreens)
Step 2: Measure Seeds
Measure out ¾ teaspoon arugula microgreens seeds. *seed measurements based on growing in an 8oz deli-style tub. For bigger trays, adjust the amount of seed to ensure even seed coverage with no seeds on top of one another but most of the soil is covered with seeds.
Step 3: Sanitize Your Seeds
It is best practice to sanitize your microgreens seeds, especially If you or anyone who will eat your microgreens have weakened immune systems. If you buy from a reputable microgreen seed company, are growing in soil (i.e. not sprouting), using potable water, and sanitizing your tools and surfaces, the associated risk is much lower. I have not heard of any illnesses or outbreaks from microgreens, though several larger companies have issued recalls.
It is important to understand that when you grow microgreens at home, you have control over many of the potential sources of contamination. By buying reputable seed companies, using clean water, growing medium without animal-based manures, and using clean tools, you are ensuring your microgreen grow is safe.
Step 4: Prepare Growing Medium
If you are using compressed coco coir, add water per the package directions to rehydrate. You can also eyeball it. Add some water, stir or massage (or wait for 15-30 minutes for the coco coir to absorb it), and repeat until the coir is moist. It is not possible to give you an exact amount of water because it depends on how much coir you will be rehydrating.
If you overwater your coco coir and have a soupy mess, simply grab a large handful and squeeze until no more water drips out.
Step 5: Fill Tray
Add at least a ½ cup of moist coco coir to the 8oz deli-style tray. If you will be unable to check your growth each day, and you expect warm weather, increase the amount of coco coir to 1 cup. Gently jiggle your tray to even out the soil distribution and use the bottom of the measuring cup to gently (but firmly) compress the soil and create an even surface for seed distribution.
Step 6: Dampen and Sow
Mist your now-even tray of coir with water (just enough that your seeds will stick) and spread seeds evenly over the soil. They should not overlap much, but can touch each other. Use the tips of your fingers, the measuring spoon, or broadcast seeds from a very small cup or bowl. This part is not an exact science.
If the seeds get clumped up, use your fingers to spread them out. Lightly mist with water.
Step 7: Cover
Place the second tray directly on top of the seeds (the topper tray). Or, place a thick piece of cardboard over your tray. Place in a warm place (no light needed at this point).
Step 8: Mist Daily
If your tray is covered by cardboard, check on your tray twice a day. Mist lightly to ensure the seeds and soil stay damp. You do not want the seeds to totally dry out.
*If your tray is covered by another tray sitting directly atop the seeds, you likely do not have to mist for a couple of days. Feel free to take a look, but avoid lifting the topper tray. Some seeds will stick to the topper tray and their growth will be disrupted. If it is very warm and you notice the soil is drying out, you can trickle water around the edges without lifting the upper tray.
In a few days, you will notice your seeds have begun to grow. If you have a topper tray, you may remove the topper to mist to ensure the tray stays moist. Continue to mist daily (or twice daily if it is warm) until there is ½ inch of growth.
Step 9: Remove Topper, Introduce Light, and Continue Watering
Once the micro arugula is about ½ inch tall, remove the topper. The microgreens will look yellowish from lack of sun. From now on, you will water by pouring rather than misting. Basically, if you continue to mist, the greens will get wet, but the growing medium will not get fully watered. To ensure the soil gets adequate water, pour water along the edges of the tray to avoid damaging the microgreens but to get the water down to the soil where it is needed.
Move the tray to a place with bright light and airflow. This can be a sunny window, a patio, or under a lamp. While direct sunlight is not bad for your microgreens, it will dry out your tray much faster. You will need to check on the tray frequently to ensure it doesn’t dry out. Again, your soil must be moist, not wet. It is tempting to water more in hot weather or in direct sunlight, but overwatering is still an issue. You will need to water more often rather than using more water. Expect to check your microgreens at least three times a day if growing outdoors in very warm weather. (or just grow indoors).
Step 10: Harvest
When the Arugula are tall enough to easily cut with a knife or scissors, they are ready to harvest. If they are outdoors, bring them indoors. There is no more need for a bright window. Harvest as much as you want to eat at a time, you do not need to harvest the whole tray all at once. Continue to water to keep the soil moist. The microgreens should remain fresh for at least a week. (if you want to keep them in a bright window, they will continue to grow quickly. You will need to eat them faster).
Discard the soil and start over. Your Microgreens will not re-grow. If you see white fuzz growing on your microgreens, that fuzz might be root hairs (totally normal). Read my post about white stuff growing on microgreens here. Learn all about arugula microgreens in this post.
A Note About Glass And Growing Microgreens
I do not use glass or Pyrex to grow microgreens. Glass is no doubt “cleaner” than growing in plastic, but when you farm for others, glass is a major no-no. Glass shattering in someone’s food supply is very bad. Glass is not allowed anywhere in commercial farming–not even glass light bulbs. Seriously, the Food Safety Modernization Act (FSMA) does not allow it. Obviously, when you are growing for your own consumption, the fear of errant glass ending up in the food supply is not a big concern. But, keep in mind that water is involved in growing microgreens. You will also be inspecting your grow, lifting, spraying, and moving them around. Consider whether glass is the best option for you.
A Note About Overwatering
It is very possible to overwater your microgreens and drown them. The goal is for moist soil, not waterlogged. If you overwater at the early stages, remove all toppers to try to dry it out before any damage is done. If you overwater at the later stages, try gently tipping your tray on its side and allowing the excess water to drain out. You can gently squeeze the tray to encourage more water to drain out.
If it is not possible to tip or dry out the tray, you can always try to poke a few holes in the bottom of the tray to drain out the excess water.
Growing in Colder Conditions
If you are growing during the cooler months (under 60F/15.5C degrees) and your grow-zone (where you grow your microgreens) temperatures are below 60 degrees, a seed heating mat will be helpful. You can grow Arugula without a seed heating mat, but they will take longer to grow. During the extra growing time, your crop is more at risk of mold. A seed heating mat like this one will speed up your grow.
Other Microgreens Varieties
Microgreens 101: Learn All About Basil Microgreens
Learn All About Sunflower Shoots—Yes, They Are Microgreens!
All About Mustard Microgreens (Intense Mustardy Flavor)
All Your Questions Answered About Radish Microgreens
Why We Should All Eat Broccoli Microgreens
Microgreens Care
3 Ways to Wash Microgreens And Avoid Mushy Microgreens
Growing Microgreens: Should You Grow Them in Your Garden?
White Fuzz on Microgreens: Is It Microgreens Mold?
Growing Microgreens: Should You Grow Them in Your Garden?
Microgreens Care: 2 Reasons You Have Gnats In Your Microgreens
