# How to Grow Microgreens Indoors in Small Trays

- Link: https://lifeandwork.blog/gardening-how-to-grow-microgreens-indoors-in-small-trays/
- Published: 2026-10-24T02:31:24-05:00
- Author: Bert Swope

If you are wondering how to grow microgreens indoors in small trays, you are not
alone. This article will show you how to plant and grow microgreen seeds to their
full potential in a container. We’ll also cover seeding density, watering and drainage,
and harvesting. So, get ready to start planting! After you’ve filled the container
with soil, the next step is to prepare the microgreen seeds. This step is relatively
easy and will be a breeze once you start to learn how to grow microgreens in trays.

## Seeding density

To calculate the correct seeding density when growing microgreens indoors, you must
know the area of the container, such as a 10″ x 4″ flat. For example, if you’re 
seeding the top 40 square inches of soil, you should plant about 80 seeds. If you
want your microgreens to be thick, you’ll need about 480 seeds. If you have extra
seeds, weigh them to know how much you need.

You may also want to add Rockwool to your soil. Rockwool is volcanic glass, which
is excellent at retaining water. It also contributes trace minerals to microgreens.
It is usually used as an insulation material, but it also works great for growing
microgreens. It’s made by mixing rock with chalk, heating it to about three thousand
degrees Fahrenheit and then blowing it into thin fibers.

Ensure that the temperature is not too low. Seeds need warmth to germinate. Microgreens
must be placed in rooms that are 70 to 75 degrees Fahrenheit or slightly cooler.
Seeds that are placed in cool rooms won’t germinate or will germinate slowly. Various
varieties of microgreens have different optimum temperatures. The University of 
Illinois Extension recommends a temperature of 70-75 degrees Fahrenheit and a humidity
of 40-60 percent.

Arugula is another tasty choice for growing microgreens indoors. It’s easy to grow,
has a peppery flavor, and is a great base for a microgreens salad. It can be grown
in a blackout dome. The lid must remain closed during the first three days. After
the second day, the microgreens should be harvested. Some microgreens are ready 
to eat within a week or two, while others can take up to 30 days.

If you’re new to microgreen gardening, you should try seeding your microgreens at
a higher density than the seeds that you’d use for your garden. This way, you can
ensure that they’ll be strong enough to withstand the elements while they grow. 
After harvesting microgreens, be sure to wipe them thoroughly and store them in 
a refrigerator. It will keep them fresher and taste better if you eat them quickly.

## Watering

The best way to water microgreens indoors is to add just enough water to the growing
tray. Do not over-water or you risk root rot. Only water the top third of the soil
profile. You should monitor your microgreens daily and adjust watering as needed.
To increase evaporation, you can also place your trays next to windows or high-volume
fans. When watering microgreens, you should always make sure to keep the soil moist
but not soggy.

One popular way to water microgreens is to water them from the bottom. Watering 
from below forces moisture into the roots, reducing the risk of mold. You should
also use bottom-watering methods to protect tender stems and leaves. Besides, bottom-
watering will help ensure even moisture throughout your trays. While watering, be
sure to check the moisture level after a few minutes and set a timer.

You can buy pump sprayers at any garden supply store and label them for water only.
Another type of sprayer can be used to apply a 3% hydrogen peroxide solution to 
sterilize trays and seeds. If you don’t want to purchase a separate sprayer for 
microgreens, you can also use the fine mist setting on your hose sprayer. For ideal
results, you can also buy a special mister nozzle for your sprayer.

You can also use soil mixes instead of topsoil. The soil mix is generally more porous
and less likely to harden when spread in a shallow layer. A great alternative is
to bake a layer of soil mix at 212 degrees Fahrenheit for 30 minutes. To prepare
the soil mix for microgreens, spread newspaper or old towels. After filling the 
trays, carefully plant the seeds. Make sure to evenly cover the seeds. If you do
not have a lot of space, use a larger tray or a larger container.

Before you water your microgreens, make sure to check the pH levels of your growing
medium. Microgreens prefer a slightly acidic environment. They can survive in a 
pH range of 5.5 to 7, but they thrive best in a narrower, almost neutral range. 
Using a simple pH tester will help you determine the proper water temperature. And
remember, if your water is too hot or too cold, microgreens will not be as healthy
as you’d like them to be.

## Drainage holes

If you’re growing microgreens indoors in trays, you’ll want to be sure you have 
the right drainage setup. Most trays are designed to hold a certain amount of water,
but some are not. To prevent root rot, drain excess water away from the roots of
microgreens. Some trays include holes for drainage, but you can also purchase ones
without holes. It’s important to drain excess water away from the roots, or you’ll
end up with microgreens that can’t tolerate that level of moisture.

To avoid watering microgreens too much, make sure that you use a tray with drainage
holes. Choosing a tray without holes could lead to mold, fungus, and airflow problems.
It also might make your microgreens unattractive, so you should choose a dark tray.
A dark tray is best for microgreens, but you can also use transparent trays.

When growing microgreens indoors in trays, you should avoid putting soil in them
because they need water to grow. Instead, you can use a flexible plastic tray with
holes. Watering from below or from the top works best. Alternatively, misting your
microgreens every few days will help to get rid of the hulls and let the plants 
grow. And as long as they don’t get too wet, they should do well.

Regardless of the method you choose, you should know how many trays you need. Remember
that you can always buy more when you have more microgreens. And if you want to 
grow them for more than one season, then investing in durable trays will save you
money and trouble. You can even get bulk discounts if you buy ten or more trays.
But before you start growing microgreens, consider the length of time you want to
grow them.

A few more tips for proper microgreen care include water temperature. Microgreens
thrive best in slightly acidic water. They can survive with pH values ranging from
5.5 to 7; however, they prefer a narrower, almost neutral range. To determine the
proper temperature, use a simple thermometer. Make sure the water temperature is
between 50-70 degrees Fahrenheit. Otherwise, they will be unable to grow properly.

## Harvesting

If you’re growing microgreens indoors, you should remember that they will only be
in the tray for nine to twelve days, so they don’t need a deeply rooted root system.
You should use a thin layer of soil to coat the cells and count the number of seeds
you want per cell. The density of the seeds will depend on how fast you’d like to
harvest them.

After seeding, keep the seeds moist but not soggy. Planting seeds too deep will 
delay germination. You can also cover the trays to keep out sunlight, but this isn’t
necessary. Instead, mist the soil daily. Gently wipe the surface of the tray after
sprinkling. Make sure not to over-wet the seeds, since this can lead to mold.

You should start harvesting microgreens when the first true leaf appears. The first
leaves are usually about an inch or two tall. To harvest these tiny vegetables, 
use sharp scissors or a harvest knife. You can purchase a Victorinox serrated knife
from a gardening store or High Moving. The greens are best stored for about two 
or three days. Pea shoots can be harvested indoors in spring. These pea shoots are
grown from organic field pea seeds. The seeds from field peas are a cover crop for
other crops.

Microgreens grow well indoors. Microgreens thrive in indoor conditions and contain
digestible vitamins, minerals, and living enzymes. These microgreens are a great
addition to sandwiches and salads. Your taste buds will thank you for giving them
a taste that is both healthy and delicious! So, start growing microgreens indoors
and see how fast they grow! There’s no need to feel guilty.

To harvest microgreens indoors, place the tray under a grow light. Water regularly.
Be sure to place it on a level surface to promote airflow. Microgreens can become
overly dry if they aren’t getting enough water. To keep them healthy, mist them 
every morning and give them their first water. Once the canopy has formed, it can
be enjoyed as is or trimmed.

[#Microgreens](https://www.youtube.com/hashtag/microgreens) [#UrbanFarming](https://www.youtube.com/hashtag/urbanfarming)
[#Howtogrowmicrogreens](https://www.youtube.com/hashtag/howtogrowmicrogreens)
Growing
Microgreens with SPROUTING TRAYS!?

> [Free eBook – Microgreens Magic: A Homemaker’s Handbook for Indoor Gardening](https://lifeandwork.blog/my-published-works/gardening-books/free-ebook-microgreens-magic-a-homemakers-handbook-for-indoor-gardening/)

[Microgreens Magic: A Homemaker’s Handbook for Indoor Gardening](https://lifeandwork.blog/my-published-works/gardening-books/free-ebook-microgreens-magic-a-homemakers-handbook-for-indoor-gardening/)

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