When and what seeds do I start indoors?
What starts indoors vs outdoors
A very simple answer is to check the back of the seed packet. Many companies will tell you if it is a direct sow seed, if it needs to start indoors, how deep to plant it, and even what months it does best in your area. The back of a seed packet can be very informational if utilized. But I will give you a general rule of thumb of what starts indoors vs. outdoors, and also explain the why behind it.
Direct Sow Seeds
Root vegetables - carrots, beets, radishes, potatoes. The general consensus of why these are not to be started indoors is because of the fragile root. Any root disturbance will likely destroy any progress of growth. You may have luck with biodegradable pots that you can just place straight into the ground after starting indoors. But I personally wouldn’t recommend it.
Squash - summer squash, zucchini, pumpkins, etc. These are a direct sow because of their rapid growth and fragile roots. Plants like squash, once they germinate, they will begin to grow faster than you may be able to transplant them into bigger pots each time. This is not to say you absolutely cannot start them indoors. I have heard of people starting squash seeds indoors time and time again, and having much success.
Cucumbers. Cucumbers grow like a wild fire and have a fragile root system. It is recommended to start them outdoors. They put on blooms and flowers rather quickly, and you’re going to need something to pollinate them!
Seeds to Start Indoors
Tomatoes - Tomatoes, you typically want to start 8 to 10 weeks before your last frost. The reason being is that it can take up to 2 and a half weeks for them to germinate indoors. Additionally, they take longer to grow flowers. In my experience, they will need transplanted and repotted two or three times depending on their growth while indoors. When repotting, you will notice fibrous hairs on the main stem, those can grow roots, if you let them. Therefore, it is recommended when transplanting to place the entire main stem into the soil so it can grow a thicker, more stable stalk. I did this each time I repotted and again when I transplanted them outdoors.
Many, if not all, pepper varieties - With many peppers (jalapeños, bell peppers, cayenne, habaneros, etc.), you will also want to start 8 to 10 weeks before your last frost. Peppers take quite a while to germinate, and even longer to start to grow upwards. In my experience, I did not have to repot them while indoors, but they also did not get nearly as much sunlight as my other indoor plants did.
Eggplants - Eggplants require to be started indoor TEN to TWELVE weeks before your last frost. I am growing eggplant for the first time this year, so I have no words of enlightenment or advice. I will report back as I continue the indoor seeds of any notes, progress, dos and don’ts.
Herbs (depending on your growing zone and length) - Herbs like dill, thyme, rosemary, basil, and parsley CAN be a direct sow outdoors. However, if you have a shorter growing season, you may want to start them indoors. Or if you’re like me, I want to jumpstart growth as soon as possible. I will be starting my herbs about 4 weeks before my last frost, in hopes I can harvest slightly sooner outdoors.
When do I start seeds indoors?
First, you need to know your areas last and first frost date. Just simply Google “my area + last frost date”. Do the same for your first frost date (although this information may not be available or reliable information just yet). Put these dates into your planner, notes, calendar, a piece of paper, memorize it. This not only tells you when you can start indoors and outdoors, but also when your garden may stop producing due to light or hard frosts.
Once you have these dates, you’re going to work backwards. Let’s use my last frost date as an example..
Last Frost Date for my area: March 22, 2025
Pepper Plant Seed I Want to Start Indoors: start 8 to 10 weeks before last frost date
What I will do is pull up a calendar and count the weeks back starting with the week of March 22. 10 weeks before my last frost will be January 11, 2025. 8 weeks before my last frost date would be January 25, 2025.
Additionally, if you’re wanting to succession sow, you may utilize BOTH of these dates, rather than one or the other. This would help you in the scenario of wanting large harvests at mostly different times. You may even want to start your pepper seeds on 1/11, 1/25 AND 2/1. Just be sure to keep your labels with dates on the seed tray so you can remember what is what. With seeds starting and germinating at different times, possibly growing multiple varieties, you just wouldn’t want to get things mixed up. Especially with peppers! How unfortunate would it be if you bit into a pepper you thought was sweet but it ended up being scorching hot because you misplaced the label!!!
Closing Notes
At the end of the day, do what you feel is best. I am no expert, I just share what I have personally learned, what I have heard from others, and I also read books. Some of the information from others, doesn’t apply or work for me. And that’s okay. Some of the information here may or may not apply or work for you—and that is okay! It is all truly trial and error. With different growing zones and climates, it’s hard to find any one single piece of advice that will work exactly the same. This is where I encourage you to meet other very local gardeners and farmers. With not only their knowledge, but sharing nearly exact climates, they will be your biggest fall back if you run into an emergency. My sister-in-law grows in a climate that is similar to mine, but her plants produced at different times, and were done for the season at different times than me. And we are only three hours away from each other.
