Disclosure: Some of the links below are affiliate links, meaning, at no additional cost to you, I will earn a commission if you make a purchase. You can read our full disclosure here.
Gardening season cannot come soon enough. We just got a fresh blanket of snow on the ground after some unseasonably warm days and I’m ready for it to melt. So many spring projects are in the works or need to be started. I need some dirt therapy. Thankfully, soon it will be time to start some of our vegetables indoors.
There are some vegetables that really thrive and transplant well when started indoors. Some… are a bit more particular when it comes to transplant time and I try to stick with direct sowing them.
Honestly, I love starting seeds indoors. I’d start them all in here if I could. It gives me the chance to work in some dirt and watch the garden begin to grow making me forget completely about the cold, wet, barren landscape outside.
8 Vegetables You Should Start Indoors
Lettuce can actually be grown indoors for a wonderful winter garden, but that’s another story for another day. Lettuce takes to transplant pretty well and starting it inside means you’ll have a jump start on your lettuce crop before the weather gets too hot.
It grows quickly so make sure you put it in a larger container. Sow a few seeds into each container about 6 weeks before your predicted last frost. Leave them in the container, covered with plastic, in an area where the temp is about 70°F. Too hot and your seeds won’t germinate.
After a few days, check for sprouts. Remove the plastic at this point and put them under a grow lamp. Thin to the best looking seedling once they get two true leaves. Harden the plants off before you transplant them. Transplanting any start is best on an overcast day with calm winds.
Broccoli and I don’t get along. I rarely have a decent sized head of broccoli before it starts to bolt in the summer heat. Why? Because I hardly ever start it inside and it takes a good amount of time to grow a decent head of broccoli.
Broccoli should be started a few weeks before lettuce. Around 7-9 weeks before your predicted last frost is a good number. Like lettuce, broccoli likes it cool so make sure you keep the sown seeds in an area where the temp is roughly 70°F. Leave them covered with plastic until you see some sprouts.
Once you see sprouts, remove the plastic and put them under a grow lamp. Thin after all seedlings get two true leaves. Do not pull the seedlings you’re thinning. Just cut them off. Pulling them can disturb the seedlings you want to keep.
Spend a few days hardening off your plants before transplant. When you harvest, leave the plants in the ground so you can enjoy the side shoots the plants will produce in the fall.
Did you know that “days to maturity” information on your seed packet for plants pre-started indoors is indicative of how long it will take to see crop after you’ve transplanted 6 week old starts? True story. So that tomato variety you bought that says 65 days… that’s 65 days plus 6 weeks.
Tomatoes should be started indoors about 6 weeks before predicted last frost. They’re finicky. They don’t like it cold, and when you transplant them you need to make sure the soil is nice and warm and the nighttime temps aren’t going to dip below 50°F.
Place tomatoes in decent sized pots so you don’t have to transplant them mid-way through starting. Tomatoes like it warm, so place your pots on a heat mat and cover with plastic in order to see good germination rates. Once you see starts, put them under a grow lamp and keep them on a heat mat. Thin once the plants get their two true leaves.
Tomatoes really benefit from hardening off, so don’t skip this essential step. Like I said, make sure the soil is warm (you can prewarm your soil if you choose) and you don’t want daytime temps below 70°F or nighttime temps below 50°F to make for the happiest tomatoes.
Like tomatoes, peppers like it warm and they take a while to actually produce fruit. Since peppers are traditionally started indoors, the seed packet information is the same. How ever many days to maturity plus 6 weeks indoors.
Start the seeds about 6 weeks before last frost and plan on (like tomatoes) leaving them indoors for at least two weeks after that date to make sure the soil is warm and the daytime and nighttime temps are sufficiently warm.
These guys like it hot, too. Place the seeds in a decent sized starting pot to avoid having to transplant into a larger container midway. Place the pots on a heat map and cover with plastic. Put under a grow lamp once you begin seeing starts keeping them on the heat mat. Thin when the plants get a set of true leaves.
Peppers also need hardened off and transplanted into warm soil. If the soil is too cold or the temps drop too much, don’t plan on a very successful harvest. You’ll get a few fruits, but not many. It’s best to err on the side of caution and wait a bit to transplant these heat loving vegetables.
Like broccoli and lettuce, cabbage is a cool weather loving vegetable. However, the soil is generally too cold to get a good start on it. So, you start it inside and get wonderful cabbages before the weather gets too hot. Plus, it can help if you have an established plant before the cabbage worms take over. It’s easier to cover….
Start cabbage in a decent sized container indoors around 70°F a few weeks before last frost. Cover the container until you see sprouts. Once it sprouts, remove the plastic and put it under a grow lamp. Don’t let it get too warm, it definitely doesn’t need a heat mat. Thin seedlings once true leaves appear.
Transplant into workable soil after hardening off for a few days on an overcast, calm day.
Starting any squash indoors has its advantages. It helps with potentially devastating squash bugs when you start the seeds indoors. Winter squash in particular can take a while to grow to maturity, so in most climates its recommended to start them indoors. Zucchini and other summer squash grow so quickly and prolifically that you can direct sow if you want.
Start seeds in containers about 6 weeks before last frost. Cover with plastic until you see sprouts. Then, uncover and put under grow lamps (or in a really bright south-facing window). Thin seedlings when they get their true leaves.
Harden off before transplanting. For best results transplant on an overcast, calm day.
If you’ve never started onions from seeds and have always used sets, you’re in for a treat. They’re actually one of my favorite crops to start from seed. It allows me tons of different varieties this way. They’re really easy, you have to start them early, but I always have better luck with home grown seedlings than sets.
You’ll want to start onions around 9-10 weeks before your last frost. In about two weeks (mid-February) is a good time for our zone (zone 5b). Use a large container (around 4×6 would be good) and fill it almost all the way with seed starting mix. Make two 1/2″ deep lines all the way across the starting mix. Sprinkle the tiny seeds in the lines you made.
Onions can take a while to sprout, so be patient. Once they do, you can clip the greens when they’re around 4 inches tall and enjoy them fresh. After last frost transplant the seedlings to a well-drained space in the garden. Plant them four seedlings to a spot.
I know, peas are usually started outdoors, but they take quite a while to produce and I’m impatient. Also, every single time I’ve tried to start peas by directly sowing, I’ve wound up with not a single plant. Not even the slightest sign of life. So, I start my peas indoors.
You’ll want to place the seeds in large containers about 6 weeks before last frost. I presoak or nick the seed which results in higher germination rates. Sow a couple of seeds in each pot about an inch down (unless your variety says otherwise). Keep the soil temp around 60°F for best results.
Make sure you harden off your plants, of course, before transplanting. Transplanting peas can be a delicate process. Make sure you disturb the root ball as little as possible. Place them about 5-6″ apart in a place that is well drained and fertile.
There are tons of seeds you can start indoors but these are 8 that I start inside every year. I often start others as well, but the more I can direct sow, the easier it is because I start running out of room to keep the starts under lights! Haha.
What are some seeds you start indoors every year?
Other Gardening Posts You’ll Love:
- How to Grow Onions From Seed: A Complete Guide
- 13 Free DIY Seed Starting Containers
- Why Your Seeds Aren’t Germinating