Starting a garden can be both exciting and a little overwhelming, especially when it comes to figuring out where to plant your seeds. When I first began gardening, I was confused about which seeds should be started indoors and which ones I could plant directly in the ground. So, I decided to dig into the details (pun intended!), and now I’m sharing what I’ve learned to make things easier for other beginner gardeners.
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Why Does It Matter?
Not all seeds are created equal when it comes to where they like to start their journey. Some plants have delicate roots and do better when they’re sown in the same spot they’ll spend the rest of their life. Others are a little bit slower to grow and benefit from starting out in a more controlled environment indoors before they’re moved out. Understanding the difference can help you have a more successful garden with healthier plants.
SEEDS TO START INDOORS
Starting seeds indoors gives some plants a head start on the growing season. This is especially useful if you live in a climate with a short growing season or if you want to get a jump on spring gardening.
Here are some of the seeds that I’ve found do best when started indoors:
1. Tomatoes
Why Start Indoors: Tomatoes need a long warm growing season to produce fruit. Starting them indoors 6-8 weeks before your last frost date means you have mature tomato plants (and ripe tomatoes) before the weather turns too hot or cold for these plants to produce.
Tips: Use a grow light if you don’t have a sunny windowsill. Transplant your tomato seedlings outside when the soil is warm and all risk of frost has passed. (Find more tips to grow tomatoes.)
2. Peppers
Why Start Indoors: Peppers, like tomatoes, thrive in warm conditions and have a slow germination process. Many peppers need 60 to 90 days to produce fruit, though some require as many as 150 days.
Tips: Start peppers indoors about 8-10 weeks before the last frost. Pepper seeds appreciate some warmth, so consider using a heat mat to speed up germination. (Learn more about growing peppers.)
3. Eggplants
Why Start Indoors: Eggplants have similar needs to tomatoes and peppers and require a long growing season. I typically don’t expect fruit until at least 100 days after I’ve planted eggplants.
Tips: Start them 8-10 weeks before the last frost in spring, and keep them warm and well-lit indoors. (Find more tips to grow eggplant.)
4. Herbs (Basil, Parsley, Thyme)
Why Start Indoors: Many herbs, especially perennial herbs like thyme, grow slowly and benefit from the extra time indoors. That way, you can transplant your herbs outside as soon as the weather’s right and start taking your first harvests.
Tips: You can start slow-growing perennial herbs and parsley as soon as 10 to 12 weeks before your last frost date. These herbs can be moved outside before your last frost has passed. Start basil about 6-8 weeks before your last frost and wait to transplant until the weather has warmed up. (Learn more about growing herbs from seed.)
5. Cabbage, Broccoli, and Cauliflower
Why Start Indoors: These cool-season crops thrive when the weather outside is cool but not freezing cold. Giving them a head start indoors means they can mature in their preferred temp range.
Tips: Start these seeds 6-8 weeks before the last frost and transplant them outdoors a couple of weeks before the last frost. (Find our guides to growing cabbage, broccoli, and cauliflower.)
SEEDS TO DIRECT SOW OUTSIDE
Some plants don’t like to be transplanted because they have sensitive roots. Others germinate and grow so quickly that it doesn’t really make sense to start them indoors and then transplant them. These seeds do best when sown directly in the ground where they’ll grow.
Here are a few seeds that I recommend sowing directly outdoors:
1. Root Vegetables (Carrots, Radishes, Beets)
Why Direct Sow: Root vegetables like carrots, radishes, and beets should always be sown directly into the garden bed. This is because these crops develop their edible parts underground, and even the slightest disturbance to their roots can result in misshapen or stunted growth. A carrot that has been transplanted, for example, might end up forked or split instead of growing straight down.
Tips: Loose, well-draining soil is key for root vegetables. They do best when the soil is fine and free of rocks or clumps, which allows their roots to grow down easily. Sow these seeds directly in rows, keeping the soil moist until germination. You can plant them as soon as the soil can be worked in early spring or in late summer for a fall crop. (Explore our guides to growing carrots, radishes, and beets.)
2. Beans (Green Beans, Pole Beans)
Why Direct Sow: Beans are fast growers, for one. Plus, they really don’t like having their roots disturbed, so planting them directly outdoors is the obvious way to go.
Tips: Wait until the soil has warmed up and the risk of frost has passed. Beans need warm soil to germinate properly. (Find more on how to grow green beans.)
3. Peas
Why Direct Sow: Like beans, peas have delicate little roots and grow quickly from seed.
Tips: Plant them as soon as the soil can be worked in the spring, even before the anticipated last frost date. (Here’s how to grow peas from seed to harvest.)
4. Zucchini and Squash
Why Direct Sow: While you can start these large warm season plants indoors, they grow very fast and prefer to be directly sown once the soil is nice and warm.
Tips: Plant by seed a week or two after the last frost date when the soil has warmed up. Make sure to give these plants plenty of space to grow! (Learn more about growing zucchini and squash.)
5. Corn
Why Direct Sow: Corn has a deep root system that doesn’t like to be disturbed. It grows best when planted directly outdoors.
Tips: Sow corn after the last frost date when the soil has warmed. Plant it in blocks rather than single rows to ensure good pollination. (Find more tips to grow your own corn.)
A FEW FINAL GARDENING TIPS FOR BEGINNERS
Know Your Last Frost Date: This date will help you time when to start seeds indoors and when to plant them outdoors. You can easily find it online based on your location.
Invest in Seed Starting Supplies: If you’re starting seeds indoors, a few basic supplies like seed starting trays, an LED grow light, and a heat mat can make a huge difference. (Find our recommended seed starting supplies on Amazon here.)
Don’t Worry About Mistakes: Gardening is all about learning, and sometimes that means making mistakes. If some of your seeds don’t sprout or your plants struggle, just see it as a learning experience for next time.
Understanding the differences between seeds that need to be started indoors and those that can be directly sown outside can make your gardening experience a lot smoother. Plus, it’s incredibly satisfying to watch those first green shoots poke through the soil, knowing that you helped them get their start! Happy gardening! 🌱
