It’s February, which is the time to finish up the garden plan you’ve been working on and get some seeds started indoors! Today we are going to learn how to use recycled egg cartons to start a variety of seeds and then transplant them to larger pots until they are ready to go outdoors. This technique works well for smaller seeds like ones in the kale family and many annual herbs and flowers.

Here are some amazing volunteers tediously transplanting this seasons greens one by one. We are using 72 cell plant trays which are the best for starting several transplants at once. You can purchase them online or find them locally at garden stores like All Seasons.

 

Materials:

  1. Pulp egg cartons.
  2. Seeds of your choice.
  3. Soil mix for seed starting
  4. A plastic tray (for holding the egg carton)
  5. Extra pots or 72 cell plant trays

Soil Recipe

One important thing about starting seeds for transplants is the soil you use. As we learned in our previous piece on germination, seeds need a balanced mix of moisture and oxygen to sprout. They also need correct temperatures and light/darkness levels, but these vary depending on the variety.

Because of this, the soil you want to use to start your seeds should be able to hold both moisture and air, and be light enough that roots and tender shoots can move freely. We make our own seed starting mix using peat moss, vermiculite and worm castings in a 2:1:1 ratio. You can also buy a seed starting mix at your local garden store and it will have most of the same ingredients. Whatever you do, don’t use dirt from your backyard because it won’t have the properties we need for this project.

Method

Some thickly sown kale. We made a mistake and over seeded! There are approximately 300 plants or more in each carton.

To start seeds in an egg carton, simply fill it with soil and sprinkle your seeds on top. Make sure to sprinkle them evenly and don’t overseed. One way to think about it is to imagine you are seasoning food. Then you can cover your seeds with a light layer of your soil mix. Occasionally, seeds like chamomile or columbine may require light for germination. When dealing with seeds like this, simply sow seeds on the surface and then cover with a very light layer of vermiculite. The reflective surface of vermiculite grains will help ensure that light is present.

Water your seeds everyday using a spray bottle, which will gently mist the soil without moving things around. Make sure your soil stays moist and never dries out completely. With the proper conditions, your seeds should start to sprout in about 1-2 weeks. Sometimes even as little as 2-3 days.

Once your sprouts are 2 inches tall, or when they have made their first true leaves, they are ready to be separated into larger pots or cell trays. Gently remove the plants from the pulp carton and make sure the roots stay moist as you do the tedious work of transplanting. You can set them on a wet paper towel while you work to reduce the risk of transplant shock. Another important thing to remember is to pre moisten your soil before transplanting. Moving young tender plants from a moist to a dry environment can cause stress and kill them.

This technique is good for starting a lot of plants in a small amount of space using a minimal amount of resources. If you are successful you will probably find that you have extra plants to share with your friends and family too.