How to Start Seedlings from Scratch (and Keep Them Alive)
Planting and germinating seedlings isn't the hard part - it's keeping them alive.
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Seedlings are very delicate. They are basically baby plants in every sense. Planting the seeds is pretty easy, but keeping them alive is muchore difficult. Once you keep your seedlings alive, you have to make sure they're strong enough before they can be planted outside.
What you Need to Start.
In order the start your seedlings you need a few things:
1. Seeds, of course. I get all of mine from Baker's Creek.
2. Soil specifically for starting seeds. This type of soil is a different light weight consistency so baby plants can easily pop up and are loaded with extra vitamins and nutrients the seeds need to sprout. I used this organic soil.
3. Containers to plant the seeds in. I saw a really neat Instagram post last year creating pods of soil and planting seeds directly in them. That way you can just plant the pod of soil straight into the garden. I don't have enough space to do that, so I have to use seed trays.
Last year, I used the trays that had biodegradable pods inside of them. I literally just cut the pods out and placed them directly in the ground. This severely stunted the root system of my plants because the delicate roots took forever to breakthrough the pods. I would not recommend this method, as enticing as it may be.
This year, I used some new type of trays called Pro Hex that are hexagons. They enable the roots the grow through the bottom of the tray and, in theory, the root systems grow stronger before they're planted in the ground. I question whether my root systems won't be tangled though, so it's still to be determined how well this new design works.
4. Labels. Make sure you label all of your plants or you won't know which is which when it's time to plant them - especially if you have different varieties of the same vegetables. Most seedlings look the same at first.
5. Sufficient lighting. I am lucky to have a floor to ceiling window in my closet that provides the perfect amount of light. All you need is enough light (not necssarily direct sunlight) to "wake up" the seeds. You can also buy various plant lights, but make sure they're not "too bright" or it could overwhelm the seedlings and dry out the soil.
6. A heat mat. This is optional. You only need a heat mat for more exotic plants that need consistently high soil temperatures. I bought mine off of Amazon here. I specifically planted the plants that I knew grew in warmer soil conditions in the tray I placed on the plant mat: pink bananas, Iraqi eggplant, Iraqi melons, pomegranates, and a South American berry. You wouldn't need a heat mat for vegetables typically grown in your USDA zone.
Starting Your Seedlings.
1. Pour your special seedling soil in your trays.
2. Saturate the soil so it is completely wet before you plant your seeds.
3. Plant seeds according to package directions. Some seeds only need to be sprinkled on top of the soil, because they need direct sunlight to sprout. Other seeds need to physically be under the soil. Make sure you check the package instructions.
4. Place plastic on top of the seeds. Usually plastic tops will come with containers you buy in the store. This helps keep the soil from drying out and also keeps the soil temperature warmer from the sun.
5. Place in a bright window or indirectly near a plant light.
6. Wait for them to sprout! It can take a few days to a few weeks, depending on the seed variety.
Keeping Seedlings Alive (The Hard Part).
1. Once your seeds start to sprout, remove the plastic covers. If a good portion of different varieties still haven't sprouted, I cover them with plastic wrap until they do.
2. Make sure to keep the soil well saturated and wet. Don't let the soil completely dry out.
3. Once the seedlings have two or more leaves on them and are about 2 inches tall, it's time to thin them. Pick out the "weaker" seedlings, keeping only the one that is the strongest.
4. When it's warm enough to move your seedlings outside, you need to give them a "hardening off" period. You can't just plant the seedlings directly in the ground because they will go into shock with the sunlight and most likely die (or be severely stunted).
Once it starts getting warmer (about 60-65°F), bring your seedlings outside (in the tray) and place them in the shade. Do not put them in direct sunlight. After a week or so of being in the shade they can be moved into direct sunlight, still in their trays. It's better to do this gradually and give them a few hours of direct sunlight each day. If it gets cold at night, especially frost, make sure to bring your seedlings back inside for the night.
5. After about three weeks of this "hardening" process, you can plant your seedlings directly in the ground where you want them to be.