How Big Should Microgreens Be Before You Harvest? Explained

Microgreens are fun to grow because they grow so fast and take up very little space. Some varieties can be ready for harvest within less than a week and others within 3-4 weeks, but to know when it is time to harvest, you need to know how tall your microgreens should be.

As a general rule, microgreens are ready to be harvested at 2-3 inches (about 5-8 cm) tall. However, the ideal height depends on the variety. While most microgreens should be 2-3 inches (5-8 cm) tall before harvesting, certain varieties such as peas should be 4-5 inches (about 10-13 cm).

This post covers exactly how you can know how tall your microgreens should be and another great trick to know when they are ready to be harvested.

How Tall Should Microgreens Be?

Since microgreens grow so fast, it is important to know how tall they should be before they are ready to be harvested. If you harvest them too soon, you end up with a smaller yield than you could have had, and if you harvest too late, your microgreens may before bitter and stringy and not nearly as nice to eat as if you harvest at the right time.

How tall microgreens should depend on which plants you are growing, but a good rule of thumb is to harvest when they are 2-3 inches (about 5-8 cm) tall. Certain plants such as peas can grow a bit more and are good when 4-5 inches (about 10-13 cm) tall.

Since everybody has different preferences, it can be beneficial to harvest about a quarter of your microgreens at the time, with a day or two in between the first few times you grow them. That way, you can find out exactly how you like them.

One of the things that make microgreens so great, other than the fact that they are packed with nutrients, is that they are extremely fast to grow, and they can be grown almost anywhere. So I recommend harvesting a little bit at the time the first time few times you grow them, so you can find out exactly what you prefer.

In my experience, there is actually an easier way to tell when microgreens are ready to be harvested than by looking at how tall they are. I get into that below.

How Do You Know When Microgreens Are Ready for Harvesting?

How tall your microgreens are can be a fine indication of when they are ready, but in my opinion, an easier way is to keep an eye out for the first set of true leaves.

Generally speaking, microgreens are ready to be harvested once the first set of true leaves appears. The first two leaves that appear on any plant are called cotyledons, or seed leaves, and are not considered true leaves. Once the first set of true leaves appear after the seed leaves, microgreens can be harvested.

I found this video where the host explains when and how to harvest microgreens excellently.

How Long Does It Take from Sowing to Harvesting Microgreens?

As with anything plant-related, it all depends on what plants and varieties you are growing, so it is impossible to say a specific number of days for how long it takes to grow microgreens. However, the difference is not that great and what all microgreens have in common is that they grow fast, so here is how long you should roughly expect to wait before harvesting your microgreens.

Microgreens generally take about 2 weeks from being sown until they are ready to be harvested. However, some plants take less time, and some take more. Examples include garden cress, which only takes about 5-7 days from being sown until they can be harvested, and parsley which takes 3-4 weeks.

I have grown microgreens (on a tiny scale) for a while now, and I enjoy it so much. It is fun to sow seeds and then harvest and eat the result in just 2 weeks or so.

Below, I cover exactly how you can get started with growing your own microgreens.

How You Can Get Started with Microgreens

Other than the fact that microgreens can be harvested in very little time after being sown, one of the things people (including myself) seem to like most about microgreens, is that they can grow almost anywhere and anytime.

When you grow microgreens, you only need a few supplies, and chances are you already have most of them.

This is what you need to start growing microgreens:

  • A plate or a tray
  • Soil without sticks and twigs
  • Seeds
  • Water
  • Grow light (only needed in the winter)

Since you will harvest your microgreens when they are still very small, you can sow them much more densely than regular plants.

To grow microgreens, cover the bottom of a plate or tray with about 1-2 inches (2.5-5 cm) of soil. It is best to use soil that does not have small sticks or twigs. Spread your seeds densely all over the soil and cover them with half an inch of soil. Water carefully 2-3 times per day until they are ready to be harvested.

It can be very beneficial to use grow lights when growing microgreens. Especially in the winter when there isn’t a lot of sunlight. In the summer, when there is a lot of sunlight, it is not required, but in my experience, grow lights still help your plants grow really well since they are more consistent than sunlight.

I bought a Click & Grow Smart Garden a while ago, and it works incredibly well for growing microgreens. It also works for growing tomatoes, lettuce, spinach, basil, and countless other plants, so you can use it for almost anything you like. It has multiple spots for plants, so you can also mix it up by growing a couple of tomato plants and a couple of different types of microgreens.

Can Microgreens Grow to Full Size?

When I first started growing microgreens, I was honestly unsure exactly what they are and what makes them different from regular plants. It turns out they are no different from regular plants, but rather regular plants grown until a certain size and harvested when they are very young.

Microgreens are grown from regular seeds and can reach full size if grown like regular plants. The difference between microgreens and regular plants is that microgreens are sown much more densely and harvested at a much earlier stage than regular plants.

The reason why you can have a lot more plants growing in a small space when growing microgreens than regular plants is that since the microgreens are not meant to get larger than a few inches, there are usually plenty of nutrients in the soil to satisfy all the plants and enough room for their roots to grow.

If you want to grow larger plants, sowing them too close will result in a lack of nutrients in the soil and a lack of room for the plants’ root systems to grow, which will significantly inhibit the growth and production.


My name is Anders, and I am the owner and writer here at Gardening Break. Gardening has always been a big part of my life. As a child, I would watch and learn as my parents worked in our garden or as my grandfather worked in his greenhouse. As I have gotten older, gardening has become a bigger and bigger part of my life. I have grown to enjoy it more and more, but I am also starting to realize just how much there is to learn about gardening, which is why I created Gardening Break in the first place; To share all the useful tips and tricks I learn along the way. You can read more about me and my mission with Gardening Break by following the "About Us"-link at the top and bottom of every page.

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