The Basics of Seed Starting
I started growing my vegetable plants from seed rather than buying seedlings from big box stores or local greenhouses for several reasons. First, I love working with soil and plants so by starting seeds I get to start gardening (albeit indoors) earlier than I would if I bought seedlings. Second, I have a very large garden, so I save money by buying seeds and starting them rather than buying plants. Lastly, one of my favorite parts of having a garden is to try many different varieties of vegetables, especially tomatoes and peppers. If I buy my seedlings from big box stores or even independent greenhouses my selection is much more limited than if I buy seeds and start my own.
Before I get into the supplies you will need to start seeds let's discuss timing. I see this question asked all the time in my online gardening groups and there is not a simple answer. The easiest way to get a rough idea of when to start your seeds is to first figure out your average last frost date in spring. There are lots of different websites and I would recommend checking several, but this one has worked well for me and gives dates close to many other sites. Once you enter your zip code, look for the 50% chance of last frost at 32°F, which for me is mid-May. Remember, this is an average and in any given year the date could easily fluctuate by a week or two. Realistically, I generally do not get my warm season crops, both directly sowed seeds and transplants, planted until the soil warms up more which is usually the first week of June for me.
Once you know your average last frost date count back, however many weeks is recommended (check your seed packet or do an online search), to figure out when you need to start seeds. For slow-growing and slow-germinating seeds like onions, celery, artichokes, and some herbs like parsley I start seeds 8-10 weeks before my last average frost date. For many cold crops like cabbage, kale, broccoli, and cauliflower I plant 7-8 weeks ahead. For peppers which can take weeks to germinate (especially the super hots), even with a heat mat, I start about 7-8 weeks before my average frost date, but I generally plant them out 2 weeks after my last frost date since peppers do not like the cold. Lastly, for tomatoes, which germinate and grow more quickly than peppers I start later, about 4 weeks before my last frost date. Again, I usually wait a week or 2 after my last frost date to transplant to make sure the air temperature and soil temperature are warm enough.
The reason seed starting dates is not an exact science is because even knowing your average last frost date you may live in an area with a microclimate that is either warmer or cooler than average. You can start tracking your temperatures where you live, but that would take years to get good data or learn to enjoy a little trial and error. As mentioned above the actual last frost date can vary because it is based on an average. Also, the temperature in which you are growing makes a difference. I found that when I started putting my seedlings into a greenhouse for a couple of weeks before I planted them, they grew much faster than when I had them growing in my cooler basement. So, I had to adjust my dates and start my seeds later to account for faster growth. The best resources I have found to help you calculate dates are from Johnny’s Selected Seeds which has SO MANY freely available calculators and tools, some of which are downloadable. My favorite tools are their seed-starting date calculator for seedlings and their fall-harvest planting calculator. They also have a succession-planting calculator which I have never used it as I do not have much time to replant most seeds due to my short growing season.
Once you have your seeds organized and dates figured out it is time to get all the supplies you need. Some of these supplies are optional so buy what you can depending on your budget. I also recommend starting just a few different types of seeds in your first year and if it goes well increase the number you grow in the years after if you want. You do not want to end up overwhelmed or with a bunch of leggy, or even worse dead seedlings because things went wrong (trust me I’ve been there).
Seedlings in 6-cell pots with a fan blowing (middle) to strengthen them and help avoid dampening off.
Before you start seeds, you need to stock up on a few supplies.
From left to right, onion seedlings under 4 foot LED 5000K lights, lettuce seedlings potted up into 3.5 inch square pots, and endive and pac choi recently transplanted into a raised bed.
I love starting my own seeds and hopefully you will too. Just remember if it does not work out great your first time, try again! My first time I started seeds I went on vacation and the person who was checking in on my seedlings overwatered them because she thought they were dying. It turns out they were dying because I had problems with dampening off (this was not her fault, some had started dying before I even left for vacataion). Unfortunately, watering even more makes dampening off worse so I lost about half or more of my seedlings that year. I have since learned that less water is usually better and I also try to time my vacations until after the majority of my plants are in the ground! Good luck and feel free to contact me with any questions!
In 2016, my family and I moved from the New York City area to small town Wisconsin. Our move, this website and blog (and our previous Etsy store) is the result of our desire over the past several years to simplify our lives, increase our quality of life, reconnect with nature, and enjoy a more self-sufficient life. I grew up as a country kid in central Pennsylvania working on my grandfather's fruit farm and as a corn "de-tassler" at a local seed farm. My background is in biology where my love of nature originated. I am a former research scientist and professor and have now transitioned to a part-time stay-at-home mom, self-employed tutor, and small business owner. Thank you for taking the time to check out my site.