Seed Germination to Seedling
I try to extend my tomato harvest and growing season by transplanting my own home grown starter transplants into my garden beds earlier than recommended. Like 6 to 8 weeks before the last frost.
I do this by adding adequate heat, light, moisture and freeze/snow protection to my raised beds. Kind of a self made micro-climate! I will discuss more on that in a separate post. To do this, I need mature and healthy transplants at a time of year when they are not yet available from the local nurseries. So, if you want to plant vegetables earlier, you have to be able to successfully grow your own transplants from seeds. A few other reasons to start your own transplants are that seeds are cheaper than plants, you can purchase a wider variety of seeds than available plants, and it is very self satisfying to transplant your own home grown starter plant.
Seed Starter Trays
First off you need to have a place to start your seeds and get them germinated. I use a Burpee Seed Starter Kit that I was given a few years ago. It provides 2 trays, each with 36 cells. A base and a clear plastic lid. I mark the tray with numbered columns and lettered rows so that I can record in a table what seed variety I sow in each cell. There are many types of seed starter cell trays that are available for purchase. I imagine you could even use ice cube trays with a hole drilled in the bottom of each tray cell if you wanted to. I think a key point in tray selection is for the cells to be relatively small because you will use a special seed starter mix for soil just for germination and the smaller the cell, the less starter mix you will need and seedlings do not need much space to get started. So, the smaller the seed cell the less space you will need to grow a lot of seedlings.
As an alternate to using the smaller cell seed starter kits, you can sow seeds directly into a small 2 inch square pot. I have had very good success with sowing in a larger pot directly and germinating the seeds in my Homemade Seed Starter. See Part 2 for more details.
Seed Starter Mix
Having an adequate seed starter mix for starting seeds is very important. You will not have much success starting seeds with your garden soil, or compost or even a pre-made potting soil mix. There are pre-made seed starter mixes available for purchase and they work well. However, you can easily mix your own. I mix six-parts peat moss with one-part perlite and two-parts vermiculite. I mix this up in a small storage container and set aside for future use.
Sowing
Now that we have discussed the trays and starter mix, it is time to sow some seeds. Start by pre-watering your seed starter mix in its storage container. (You want to work with moist starter mix because watering after you sow the seeds will likely screw up the seed planting depth due to the force of the water eroding the surface.) Place the starter mix in each seed starter cell of the tray. Then follow the plants recommendations for sowing depth. As a general rule, depth of sowing is directly proportional to seed size. The smaller the seed, the shallower the depth of sowing. Conversely the larger the seed the deeper the depth. Generally sowing depth is 2-3 times the seed size. You really do not need to overthink this. In reality there is not a lot of variation in seed size for most plants the common gardener will grow. The smaller seeds being about 1/16 in in diameter. Like lettuce and radish seeds. And larger seeds being ½ to ¾ inch in size. Like corn, beans, cucumber or squash seeds. The main point is to make sure your smaller seeds are covered and the larger seeds are not so deep that they delay emergence.
Once the seeds are sowed and covered, mist a little more water over the top and cover with plastic. If you purchased a seed starter kit then it probably came with a clear plastic cover. If not then use plastic saran wrap to cover the tray. Keep in a warm spot, 75-85 degrees and your seeds should emerge in 7 to 14 days depending on the seed variety. They will not need sun or artificial light until they emerge.
