Two frequently asked questions by people starting to grow microgreens are: “What are cotyledons?”, and “What are true leaves on microgreens?”
Microgreen seed vendors and writers often forget to explain microgreen terminology before using uncommon words or phrases. We say things like “Harvest during the cotyledon stage” or “Wait until the first true leaves form before harvesting the microgreens.”
This only confuses people who have just started growing microgreens. Making the simple task of growing microgreens seem more difficult or too technical than it is, and lowering the chances that they’ll try growing their own microgreens.
Home Microgreens aims to make growing microgreens as easy and fun as possible. Hopefully, this article will help those new to microgreens by explaining the terminology.
Growing microgreens is easy, and we want you to have trays of microgreens ready to harvest every day of the year.
What Are True Leaves?
The photo above is Purple Wave Mustard microgreens showing both cotyledons and the first true leaves.
If you haven’t read the article on cotyledons or seed leaves, you can read that article by clicking this link.
Which leaves in the photo are the true leaves?
First true leaves are smaller versions of what the larger mature leaves will be, so they are the leaves that have vascular structures and frilly edges. Now not every first true leaf has frilly edges like the mustard shown above. But they will look more like mature plant leaves.
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Cotyledons are usually smooth and plain looking, with very basic shapes like ovals or heart-shaped in the case of the mustard above.
Below, we’ve labeled some cotyledons and true leaves on the mustard microgreen photo (you can click on either picture to expand the size).
You can see that the cotyledons, or seed leaves, are heart-shaped with smooth edges.
While the first true leaves are more vascular, lobed, and have frills along the edge.
First true leaves, without a doubt, start providing energy for the plant by photosynthesis. There’s some debate if cotyledons are able to photosynthesize. Many sources on the internet say they don’t.
However, a study by Zhang et al. (2010) shows that cotyledons of some plants do contribute energy to the plant by photosynthesis.
We believe that the cotyledons of many plants grown as microgreens produce chlorophyll and help contribute more nutrition to microgreens. The main reason we think that is how much the microgreens grow before growing their first true leaves.
But this isn’t an article about cotyledons, but we want you to understand how the plants grow so you can produce the most nutritious and flavorful microgreens possible.
We’ll get back to the topic at hand.
Harvest Before or After the First True Leaves Form?
Well, that depends on the microgreen.
You harvest many microgreens before the first true leaf forms, for example, broccoli, kohlrabi, turnips, radishes, and many more.
Others, like the mustard microgreens shown above, should be harvested as the first true leaves form. Not that you can’t eat the cotyledons because you do harvest them along with the true leaves.
Purple Wave Mustard microgreen. The plant rests on two cotyledons, and the first true leaves are growing between them.
Flavor is the Real Reason
We wait to harvest some microgreens because the first true leaves add much more flavor to the microgreens.
The flavor will be more intense after the true leaves form. Generally, before harvest, we wait for the first true leaves to form on herb microgreens, like basil, cilantro, and parsley. But we wait on some vegetable microgreens, like mustards and celery.
Confused When to Harvest What?
We know it’s confusing, and we’ll publish an article on which microgreens should be harvested prior to or after the formation of the first true leaves very soon.
We’ll post a link here when that article is published. Or, you can sign-up below to receive a weekly e-mail update with links to the newest articles and growing tips.
More Photos of Microgreen First True Leaves
Below are three more microgreen varieties. Again, you can click the image, and the photo will expand.
The cotyledons are the fan-shaped leaves at the top and bottom of the photo. The first true leaves are coming out of the middle of the plant, pointing east & west.
In this image of celery microgreens, all of the leaves shown are the first true leaves. The cotyledons have either fallen off or can’t be seen below.
The cilantro cotyledons are narrow and oval. The first true leaves are tri-lobed.
Have a Question?
If you have any questions about the information in this post or microgreens in general, please comment below or contact me using the Ask a Question page.
