Small-Space Seed Starting Part 1.5: What Do I Do Once Seeds Have Sprouted?

*This post is Part 1.5 of a series that will take you from the very beginnings of starting seeds in a small space, such as a home, apartment, or backyard greenhouse, all the way through to getting your young plants ready to plant outside. See the other posts in this series for a complete guide on how to start and grow seeds in the small space of a home or apartment (useful for small-scale greenhouse growing, too!)

There is a bit of an interim step between the germination stage and the potting up step of this small-space seed-starting method. The timing of this step will be different for different types of vegetables and flowers, because they all have their own internal clocks; their individual timelines to germination.

Germination Begins

About a week after planting you will see the earliest-germinating seeds start to pop above the surface. It starts with one or two and then over the next couple of days quickly becomes a pretty virulent pot of popping seedlings. Sometimes, given the high density of seed in the pot with this method, you will even see the mass of seedlings lifting up an entire layer of dirt, looking like they are wearing something of a seedling cap.

young tomato seedlings

When you only have one or two seeds popping, you can continue on as you are, monitoring moisture and keeping them in the dark. They’ll look a little anemic and yellow at this point, but that’s okay. These just-germinating seedlings don’t need to photosynthesize yet, and you’ll get a better overall yield by keeping them under germination conditions for another day or three.

*The one exception to this rule is things like cucumbers and squash—those larger seeds which we discussed starting preferably in individual peat or paper pots, that will not be potted up. For those seedlings, remove them from the dark and put them in a bright space as soon as you see them break the surface of the soil.

peaking squash seed, newly germinated

These seeds grow very quickly and if left in a dark space for even a day longer than necessary, will grow a long, leggy, weak stem.

Since you are not potting these seedlings into new pots, you will not be able to correct this in the transplanting. By putting them to the light as early as possible, you will prevent this legginess and weakness.

Show Them the Light

When you have several seedlings that have emerged—something that looks to you like most of the seed has begun to germinate and break through—you can now move the seeds out of their makeshift germination “chamber.”

germinated eggplant seedlings

Take only the germination pots with plenty of emerged and emerging seedlings and bring them out of the dark. Place them in a space with plenty of light and warmth. If you have your grow lights already in place, you can set your germinated pots under them—just don’t place the light too close to the pots, as these young seedlings can still easily dry out and can easily burn if the light is too hot. If your lights are not set up yet, place them in a bright space or on a sunny windowsill. Just take care that the light is not too bright or too hot, which again, could cause the tiny plants to dry out and burn.

small seedlings germinating

Though soon enough the right light will be important for strong stems and good growth, at the early in-between stage a bright place that is maybe a little less than optimal in the light department is okay.

The subsequent “potting up” step will correct a lot of early issues anyway, and your plant is not really making its own food yet, so its needs are less.

Simply moving them into a well-lit room will be enough for the time being.

Within a week you will want the seeds under grow lights, but this gives you a bit of a breather while the seedlings are slow-growing to get the lights set up and let the just-germinated seedlings mature for the next step, potting up into individual plant cells or pots.

Keep Germinated Seeds Warm, Wet, and Draft-Free

Really, the heading says it all. To maintain your young seedlings at this stage, all they really need is for you to maintain them in a bright, warm, space protected from drafts, and to keep their soil wet—but not too wet!

As before, soil should be kept moist and should not be allowed to dry out. Seedlings will die off quickly if their soil is allowed to become dry. Bottom-watering is still best, and you should still only water until the top of the soil just darkens with moisture. The seedlings will tolerate over-watering better than under-watering, but they still will not tolerate over-watering that well. Over-watering is a prime factor in rotting and disease. Do not let the soil get so wet that the pot is sopping or dripping.




In terms of “warm,” comfortable room temperature, perhaps a little on the warmer side of things, will be enough to maintain your seedlings until it is time to pot them up. Something above 65F and in the range of 65-75F is a good, comfortable temperature for a seedling—about the same temperatures that you kept them at for germinating and sprouting. You do not necessarily need to increase the temperature of your home to achieve this. Selecting a spot closer to a heat source (but away from direct-blowing hot heat) will be enough to increase the seedlings’ climate those few degrees.

Just A Little Longer Until Potting Up

seedlings potted up and ready to grow

This interim stage will only last for about a week or two, and then it will be time to move on to the next stage, when it will be time to split these little seedlings into individual pots or cells of a cell pack to live on their own.

This is where it starts to get exciting—where you’ll start to really see these sprouts as plants with promise, well on their way to gaining size and stature, ready for planting out in your garden in another month or so.

Be sure to subscribe and follow along so that you don’t miss a post of this series. Together, we’ll move through this process of small-space seed starting. You’ll be amazed at just how much you can grow in even the most limited of space!

Missed a post?

Find Part 1 of Small Space Seed Starting Here

Find Seed-Starting Questions and Answers Here

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