This season is something special with seed starting for me. It’s not only my fifth season starting seeds, but it is where I have ease and confidence in starting these seedlings. It takes the right supplies, as well as following the right steps, much in the same way as following a recipe when cooking or baking.
Wondering about what supplies you need? Check out this post that describes everything that I use for my seed starting process.
Two Important Planting Dates for Seed Starting
With recipes, I start with pre-heating the oven, if need be, as well as some other preliminary steps. For seed starting, it is essential to know at least two dates.
Late Spring Planting Date for Seed Starting
The first date is one that all gardeners will teach one about. That is your last frost date in the spring. I live in Northwestern Pennsylvania in the mountains of the Pennsylvania Wilds. My average last frost date is May 15. This is a rough estimate. When observing the forecast, if the weather is calling for frost on May 15, it is necessary to wait until after the chance of frost is gone. In the same way, I could begin planting by May 10 if the weather is called to be warm, sunny, and frost free. It all depends on the season for that year.
I like to go off of what other plants are doing. When my irises are in bloom, it is okay to plant the pepper plants. This isn’t a guarantee, but neither is planting at your average last frost date. Keep everything in mind from what is blooming to what you can plan logically.
To check for your average last frost date for your home, search in Google “last frost date for {name of your town} {state}”. This will bring you sources to skim through to discover when your last frost date is.
Early Spring Planting Date
The second date to keep in mind is when daffodils are approximately in bloom. This is around the first week of April for me. My cell phone camera takes pictures and identifies them by the date they were taken. My pictures of my daffodils in bloom are always that first week of April. This April date is for planting out cool hardy annuals. This is my spring flower garden, but it is also some cool hardy vegetables, such as lettuce, radish, peas, and the brassica family.
Lastly, keep in mind when your soil is first able to be worked. Some flowers and vegetables can be planted as soon as the soil is thawed and able to be worked. When the first full week of March comes, I’m out planting some seeds in our raised beds such as radish, spinach, and peas.
When to Start Seeds
On seed packets, the company should be providing information on how early to start seeds indoors or when to direct seed outdoors based on the last frost date or the date that you will be planting out.
An easy example of this is tomato plants. They should be started 6-8 weeks before the last frost. To find when 8 weeks before May 15 is for me, I’ll search “8 weeks before 5/15”. The search results will provide with the exact date, which is March 20.
Curious about the best places to order seeds from? Check out this post, “Ordering Seeds for the Vegetable Garden.”
Using Excel
On and excel document, I enter this information to keep it organized so that when March 20 comes around, I am ready to start these seeds.
This excel document has been a game changer when it deals with seed starting. I just have to find the date of the current week, skim down that column to see if anything needs started. It also works great to include the time frame of 8 to 6 weeks before the last frost. That way if I would forget about the tomato seeds, or let’s say didn’t have them ordered, I could wait a week to start them, and they would still be ready for my May planting.
Without having this excel sheet, or let alone anything written down, I was starting tomatoes too late, as well as peppers. Starting peppers were my biggest nemesis for years one and three of seed starting. I felt as if they were super hard to start and I wasn’t capable of growing my own pepper plants. It really came down to starting them early enough to have them to a good size for planting in the garden.
Here is a copy of my Excel sheet for my 2023 garden season with early spring planting date of first week of April and late spring planting date of May 15.
I refer to this excel document weekly to determine what seeds I am starting indoors, or outdoors. Then, I search for the seeds in my seed tote. I take the seeds with me to my seed starting table.
Prepare the Soil Medium for Seeds
At my seed starting workspace, which is a 2’ x 4’ adjustable height foldable table in the basement, I keep a bale of all-purpose soil medium and a tuff bin. Scoop the soil medium out of the large bag and fill the bin about 2/3 to ¾ of the way full. Add water until all the soil is wet to touch. If it is too wet when picked up where it is dripping water, add a half a scoop of soil medium at a time. If it is too dry, add a small amount of water at a time, about a cup at a time.
Place a 72-cell plug tray into a leak-proof tray. Fill the plug tray with the moisten soil medium.
Add Seeds
Seeds have various planting depths. Seed packets should provide more information. When in doubt with information, access the Grower’s Library at Johnny’s Select Seeds.
Some seeds will be surfaced sown, meaning the seeds will just be spread on top of the soil medium. These seeds need light for germination. With these surface sow seeds, I like to think about how poppies will drop their seeds naturally to where the seed will be on the surface until the next growing season.
Other seeds need to be planted in the soil at various depths. They need darkness in order to germinate. If this is the case, use a pencil or a skinny popsicle stick to create a hole in the cell for the seed to drop down into.
Add one to three seeds per cell. If I have grown a variety before and know how prolific they are when germinating, I will sow one seed per cell for most cells. Some do end up with two so that if some don’t germinate, I can pull seconds out and move them to a different cell. For smaller seeds, it is harder to sow just one or two seeds per cell. In this case, I sprinkle the seeds across all the cells.
Using a toothpick with saliva also works to only have a few seeds per cell, but I don’t do this because when I tried this with tiny petunia seeds, I still ended up with 10 seeds per cell in some cases. I had lots of petunias that year! But, I didn’t find the effort in using a toothpick to pick up a few seeds, when it still picked up lots of seeds for me anyways.
Label Seeds
Label a new popsicle stick, or another labeling supply, to write the name of the variety on it. Then insert this identification stick into a cell with the seed. I keep these ID sticks near the center where it meets another variety.
Seed Storage
When putting seeds away, some seed packets will reseal with the glue on their envelopes. For the ones that don’t reseal, I take sewing pins and pin the top shut. Some other things that one can do is fold down the top two times, re-glue the seed envelope, staple, or tape it shut.
Place the seed packets back into their storage container, even if there are no seeds left. I will make a mark on the seed packet if it is empty, but the seed packet will provide valuable information during the growing season. Also, if it is a new variety you love, then you will know what variety to reorder to plant again.
Start Seed Germination
For seeds, many take light to germinate, while others need darkness. If the seed takes light, move the seed trays to underneath a grow light. The grow light should be able 4 inches above the tops of the trays. The light should span the whole width of the seed tray, so adjust accordingly.
If the seeds do not require light, seeds can be put in a warm location, including on top of the refrigerator, near a heat source like a pellet stove, or on top of seedling heat mats.
Germination may take a few days. Most seeds germinate within 7 to 14 days, but each seed variety varies, so check on your seed packet for information or go to Johnny’s Select Seeds’ Grower’s Library.
After Seed Starting
Next, seeds will germinate and be in the next youngest stage of life. Once this happens and they continue to grow, there’s other steps in taking care of them. Stay tuned for my next post starting with the germination process, “Caring for Seedlings Indoors.”
Happy Seed Starting Season!