Seed Starting

TIME TO START SEEDS FOR YOUR SUMMER GARDEN

 


What you need:

  • Soilless potting mix
  • Plastic sandwich bags
  • Germinating containers
  • Plant labels
  • Shop Lights
  • Heat mat (optional)
  • Cell trays with domes
  • 3-4" containers

Use a good, well draining, seed starting mix or even potting soil without fertilizer. I have found that using a sterilized mix is not that important as long as you follow temperature and watering instructions. I like mixes containing mycorrhizae, a good fungus aiding root development. Espoma, and many other manufacturers, make seed starting mixes with mycorrhizae added. It really does develop plants with stronger and larger root systems.

Day before potting soak seeds to jump start germination. I put seeds on a paper towel, fold it, wet it with warm water and put it into a small sandwich bag. Label the bag with the seed name. I have used masking tape or stick on filing labels. Then place it in a warm place for overnight. I use and like a seedling heat mat from Hydrofarm, but any warm spot (around 80) would work.
Seedling heat mats raise ambient temperature by 10-15 degrees. Warmth is the most important requirement for germination. Too cold and seeds will rot, too high and they will not germinate. The best is between 80-85 degrees in general.

The same day get your potting mix, containers and labels ready

You can use any shallow (1.2”-2.5”) container – mushroom plastic container, circular oatmeal carton, ½ gal orange juice or milk carton and cut it to size. Punch or burn holes for drainage. I have used metal skewers that I heat up on my stove to burn drain holes into plastic containers.

Put some potting mix into the container, filling it almost to the top and pack it in very lightly. Sit the container in shallow tray of water for several hours, ideally overnight. That makes sure the mix is completely hydrated.

Working with one sandwich baggie at a time, I take out the paper towel and spread it out on the work counter. Write a label and stick it into the side of the container. Do not cut your labels too tall, you need to be able to cover the container. 1.5” above soil level is great.

Then place seeds into the container on top of the wetted mix.  If you want to start directrly in pots or cell trays then use 3 seeds per cell. I use toothpicks to gently nudge seeds apart if they are too close together of stuck. Be gentle, as they may already have started germination. Cover with another thin layer of potting soil (1/8”) and spray. Write a label (plant label, popsicle stick, a strip cut from window blinds, etc). Put a container onto a tray. Cover the pot with plastic wrap and and rubber band or if you have cell tray, cover with the dome and put it onto heating mat or a warm place.

Start checking seeds twice a day. Pepper seeds may take up to 10 days to germinate. Tomato seeds usually emerge within 3-4 days, but may also take a week. Check your seed packet for germination requirements. If the seeds do not come up within a week or so, I gently dig around with a toothpick. If I find a small root sticking out of a seed, I cover it up. If the seed rotted, you will find no trace of it after 7 days. If the seed appears dry (and the surrounding soil is dry as well and container feels light), soak it on a tray of water and recover. If seeds rotted, you need to start again and keep the temperature higher.

Once the seedlings emerged, I move them to cell trays. I use Plantation cell trays and like to cut a 72 cell tray to 6 with scissors. Easier to handle and if some seeds grow faster, you can just lift those out and put them under higher lights. Easier to water too.

I use a stem of a small dessert spoon or a popsicle stick for transplanting to a cell tray. Scoop out small amount of mix to a neighboring cell. Scoop the plants out and gently separate with toothpicks if they are tangled. Usually there are only a few roots at this stage and they if you separated the seeds enough at planting time, there usually is very little entangling. If the roots are too long, I usually just snip them shorter. Seedlings take well to root pruning at this stage.

As soon as they emerge, take off the cover and move them under lights. I use shop lights suspended 2”-4” above plants. As the plants grow, lift the grow lights, keeping them around 4” above the tops of the seedlings. I use a fan to circulate air to prevent dampening off. Lift the pots daily to feel  their weight. You will learn quickly to knbow if they are dry and need watering. Bottom water if you can. I spray on top too in the beginning, but it is imperative to have a good airflow if you get the foliage wet.

Let the seedlings grow until 2 sets of true leaves appear bottom watering them if needed. The seedlings do not need fertilizer until a set of true leaves appears. When the seedlings come up they have a set of thin seed leaves. They nourish the plant until it grows roots to feed itself. Only when the true leaves appear, will the seedling be able to feed itself through its root system and photosynthesis. 

Once the seedlings are 3-4" tall, then transplant into a 3-4” plastic pot, newspaper pot, coffee cup, etc.Usually plants survive root disturbance well, it may set them back a week until they regrow roots that were damaged. 

 

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