What Are True Leaves on a Vegetable Seedling?

What Are True Leaves on a Vegetable Seedling

If you are new to vegetable gardening, you probably have heard the phrase “true leaves” a time or two. This is especially true if growing from seed, where this phrase is used most often. But what exactly are true leaves?

When a seed first emerges from the soil, or potting mixture, it has a set of two leaves called cotyledons. The cotyledons are actually a part of the seed, and act as a food source for the sprouting seedling. At this time the seedling does not conduct photosynthesis. It gets all its food and nutrition from the cotyledons.

Cotyledons and True Leaf of a Seedling

As the seedling becomes stronger and healthier, it will begin to form two more leaves that look very different from the cotyledons. The true leaves will look more like what the plant’s leaves look like when mature. Once the true leaves are present, the plant is now actively photosynthesizing. Eventually the cotyledons will wither and fall off as the true leaves take over the job of feeding the plant.

True Leaves On a Tomato Seedlings

Knowing how to identify a seedling’s true leaves is important if starting seeds in pots for later transplanting into the vegetable garden. Some vegetables should not be transplanted in the vegetable garden until at least two true leaves appear. This is true for cucumbers, squash, pumpkins, and melons. Hopefully now you understand what is meant by “true leaves”.

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16 Comments on What Are True Leaves on a Vegetable Seedling?

  1. Tee –
    Just thought I’d let you know here in Florida my tomato plant have already started to fruit. The last frost was back in February so I was able to get my plants out early.

    • Wow! THat’s awesome Frank! I’m kind of jealous. I haven’t even started my seeds yet. It won’t be long now!

      I’ll start them this weekend and probably plant around the end of April since my last frost date is around April 15th.

  2. I started several plants from seed. However, I don’t think I’m doing too well because they have not started their true leaves yet. What can I be doing wrong? They are about 4″ tall now.

    • Hi George – What kind of plants are they? Did you start them indoors, or outdoors? Are they tall and leggy, or as wide as they are tall?

      • I am having the same problem as George and myine are long and skinny. I moved them to where there is more light is there still hope for them?

        • Generally they are OK until they start to fall over. Once they fall over they will die. If you can get them to proper lighting before they get so leggy they fall they can recover.

  3. Hi there!
    I’ve just started seeds for the first time (yay!) – tomato, pepper, cantelope and Brussels sprouts. Your post here has been tremendously helpful – thank you! Almost all of my seedlings have begun to come up, but now I need to know whether or not to pinch off the cotyledons… I’m sure I was told to do so in the past, but I can’t recall if that applied to vegetables too. Please advise.

    • Hi Erin – I’m glad you have started seeds and they are sprouting! There is no need to pinch off the cotyledons, just let them be. Once the true leaves of the plant “take over” the cotyledons will die off on their own.

      Thanks for your question and for stopping by!

  4. How long does it take for the first true leaves to appear on peppers, and zucchini?

    • Hi Jennifer – the true leaves should appear within a couple weeks. What variety the plant is and growing conditions can affect the growth rate, but generally two weeks is plenty of time for the true leaves to appear.

  5. Maureen O'Connell // May 24, 2011 at 6:45 pm // Reply

    I would like to know about the flowers on my cucumbers and squash. They produce many flowers, they open, and then die but not any veggies.
    What should I do to change this situation? Thank you, Maureen from Florida

    • Hi Maureen – Cucumbers and squash flowers need to be pollinated. Most of the time Mother Nature takes care of this via bees and other pollinators. If your plants are producing male and female flowers but are dying off without any fruit, then it’s mostly due to a lack of pollination and a lack of pollinators.

      You can hand pollinate them by transferring the pollen from male flowers to the female flowers using a very small paint brush, or plant flowers and herbs throughout your yard that attract bees.

  6. Hi,
    It’s the first that I’m planting seeds indoors. It’s been exactly 2 weeks and my cucumbers, peppers, and tomatoes have not sprouted. They are in a shady, 70F area in my house. Should I plant them again, give more time, change area/temp? I have not watered except when I planted them.
    I also planted herbs, and some flower seeds in a sunny area. Nothing. What I’m I doing wrong?

  7. Hi! I planted my seedlings and they have all sprouted. Watermelons, cucumbers, tomotaoes and chives. Green beans were also in the group, but only one sprouted and then some kind of odd little clear worm ended up in its planter and started eating the roots after a couple of weeks. My real question is about true leaves, though. My cucumbers have started to get their true leaves, and a couple of my watermelons, and only one of my tomato seedlings. They have been sprouted for weeks now, possibly a month or more. I didn’t know what a true leaf was until I read this article, and I actually have just finished transferring them all to bigger pots until I can build my raised bed.

    Will the seedlings that have not yet received their true leaves be harmed or not produce fruit and vegetables?

    Also, my mature tomato plant has produced buds, but only has bloomed and has now started to die without producing any fruit. The others are still green and unopened, should I be concerned about disease or the plant being stressed?

  8. I am growing pumpkins and they just sprouted 2weeks ago and they haven’t got there true leaves yet. what is the problem?

  9. Can you trim off the cotyledons leaves on pumpkin , squash, watermelon and cucumber plants ? Without harming the plants

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