Caring for Seedling Starts to Ensure Their Success
With care and attention after germination, your seedlings will grow into vigorous, healthy juvenile plants ready to be transplanted outside into the garden when the weather is right.
How Much Light Do They Need?
When grown outdoors, vegetable plants require a spot where they get a minimum of six hours of sunlight daily. Indoors, they need a place that gets 12-16 hours of daylight. If your home doesn’t get enough natural light, use a grow light to supplement sunlight.
The best spots in your home for your seedlings are close to south- or west-facing windows. South-facing windows get the most sun; they typically have light streaming through them for most, if not all, of the day. West-facing windows stream direct sunlight for a good portion of the day and are often shaded from the intense sun in the late afternoon.
At What Temperature Should I Keep Them?
- Most vegetable plants prefer daytime air temperatures between 75°F and 85°F.
- Keep the nighttime temperature between 60°F and 75°F. Cooler nights mimic the drop in outdoor temperatures when the sun goes down.
- Never let the temperature drop below 50°F.
Watch out for extreme temperature fluctuations indoors — these can still plant growth and affect yields. Avoid putting your seedlings where they can feel cold drafts from an exterior door.
How Often Do They Need Watering?
The goal is to keep the potting soil moist without it being saturated. If it is too wet, the water pushes air out of the potting mix, starving the roots of oxygen.
Water your containers from the bottom, setting them in a shallow pan of water. The potting soil will wick up moisture through the drainage holes, stopping once it has enough. Watering this way helps prevent overwatering and won’t dislodge the seeds or seedlings like overhead watering.
Do I Need to Fertilize Seedlings?
There isn’t a need to fertilize newly germinated seedlings. The endosperm within the seed has enough “food” to get the plant started until it grows roots capable of taking in nutrients from the potting soil.
When your seedlings develop the second (or third) set of true leaves, you need to start fertilizing them. They have used up all of the reserves stored within the seed and need nutrients for growth.
Now it’s time to feed your seedlings a half dose of all-purpose fertilizer every two weeks.
