6 Plants You Should Never Start Indoors (Sowing Outdoors vs. Indoors)
This post may contain affiliate links from which I will earn a commission. Learn more in our disclosure.
Did you know that some plants should NEVER be started indoors? It’s true! In this post, we’re going to talk about sowing seeds indoors vs. outdoors plus I’m sharing a list of seeds you should never sow outdoors, and why that is.

Growing from seed is a great way to get more out of your garden for less money, but you only save money if your plants grow. So let’s talk about the best place to sow your precious seeds.
If you’re like me, time is precious. And you also care about saving money. When I spend time gardening I want both my time and my money to be spent well. I buy organic / heirloom seeds and I want them to really take off after planting them.
One thing I didn’t know when I started gardening is that some seeds do better started indoors vs. outdoors, and there are some seeds that you should never start indoors. So here’s what I learned.
Previously, we talked about the basics of starting seeds indoors, as well as money-saving ways to start seeds on a budget. Today, we’ll be looking at another aspect of starting seeds – deciding where to start your seeds and which location is best for starting a variety of seeds.
Whether you are planning your traditional, lasagna, or raised bed garden, or getting your fall vegetable garden ready, these tips are sure to help.
Enter your email and I'll send it straight to your inbox. Plus, you'll get healthy living updates too.
Growing From Seed
Growing from seed is true labor of love that has lots of benefits. When you start your garden from seeds, you can save money, increase yield, and also have control over the quality of your plants.
However, you can only do all of those things if your seeds take root and your seedlings thrive. That’s why it’s important to know as much as possible about starting seeds.
One question you might be wondering about is whether to start your seeds indoors or outdoors. Another thing to know is that they are some plants that you definitely should NOT start indoors.
We’ll cover both of those topics today and hopefully the information in this post can help you decide the best option for your plants.
Sowing Seeds Indoors vs. Outdoors
Indoor Seed Starting Pros and Cons
Pros: Indoor seed starting gives you lots of control. You can adjust moisture and warmth as needed, and seedlings started indoors are less prone to pests and diseases.
Cons: Indoor seed starting takes quite a bit of space. You also typically need to provide light and warmth, which can be a challenge depending on your living situation.
Outdoor Seed Starting Pros and Cons
Pros: Outdoor seed starting is quick and easy for the most part, once your soil is ready.
Cons: Sowing directly outdoors can be unpredictable. You might have to water the plants quite a bit, the weather might not cooperate, and a critter might decide to destroy all of your hard work. You’ll also need to keep a close eye on weeds, especially during the first few weeks.
Seeds You Can / Should Start Indoors
Some seeds work best when started indoors.
One reason why some seeds do better starting indoors is that they transplant well. Seeds that start well indoors are typically more tender and heat-loving plants.
The following plants are perfect for growing from seed indoors. Although some of these plants are more finicky than others, if you’re careful when transplanting (as you should be with any plant) and harden off your seedlings well, you can better insure success.
- Broccoli
- Brussels sprouts
- Cauliflower
- Eggplant
- Kale
- Onion
- Okra
- Pepper
- Sweet Potato
- Tomato
- Peppers
- Sage
- Lavender
- Lemon Balm
- Mint
- Oregano
- Rosemary
- Thyme
- Tomatillos
Here’s an easy to read list of plants that are better suited to starting outdoors.
- Corn
- Beet
- Cucumber
- Radishes
- Arugula
- Squash
- Turnips
- Rutabaga
- Parsnip
- Carrots
- Winter Squash
- Pumpkins
- Beans
- Peas
- Lettuce
Seeds That Can Be Started Either Indoors or Outdoors
The following seeds can either be started indoors or directly sowed into your garden when the weather warms up. Growing from seed indoors will help you get a jump start on the growing season, but the seeds are hardy enough that it won’t wreck your growing season if you don’t do it.
- Cabbages
- Lettuces
- Unusual varieties of squash
- Spinach
- Chard
- Basil
- Amaranth
- Artichoke
- Chives
- Watercress
- Leeks
- Peanuts
- Tomatoes
6 Plants You Should NEVER Start Indoors
No matter how careful you are, there’s bound to be some kind damage when transplanting, so sowing outdoors can often be the best way to go, regardless of the plant. However, the following plants are especially prone to trouble.
One thing that’s helpful is that most of these plants are some of the fastest growing vegetables, so even if you can’t start them indoors, you can still harvest them pretty quickly!
1. Root Crops
Root crops simply don’t transplant well. This kind of makes sense because the plant is really the root. If the root gets damaged, then the plants won’t do well at all. Directly sowing all root crops including parsnip, turnips, carrots, beets, radishes, and potatoes is the way to go. (source)
2. Squashes
Squashes (squash, zucchini, pumpkins) and cucumbers grow extremely fast and large. As a result, they’re also tough to transplant. It’s easy to snap their stems, they are easily damaged and unmanageable.
Also, if you need to hold off transplanting them due to a weather change, they can get very unwieldy indoors and they get stressed, making it even harder.
3. Corn
Corn typically doesn’t transplant well. You can try it, but it’s tough. This article has some tips on how to make it work should you wish to try.
4. Beans
Beans grow quickly as well. Starting them indoors will result in the same problems as with the squash and cucumber plants.
5. Peas
Peas are similar to beans. As such, they will also grow very quickly and again, moving them will prove to be problematic.
6. Cucumbers
Cucumbers are similar to squashes in this respect. They grow quickly and don’t transplant well.
7. Lettuce
OK so this is #7, but, I’m adding it in here anyhow.
Actually you can start lettuce indoors as well as outdoors, but lettuce grows really well being planted outdoors so many people choose not to start these plants inside. Also, if you are going to plant in a high intensity manner (pick and go), then transplanting doesn’t make sense; it’s better to plant quickly and efficiently directly outdoors.
Sowing Seeds Indoors or Outdoors?
Growing from seed is one of the oldest ways of saving money in the gardener’s arsenal, but it’s a little more complicated than just tossing seeds in the ground.
Growing from seed is a fun, money-saving option for anyone who gardens, and knowing whether to start them indoors or out can be a huge help.
Now that you know about sowing seeds indoors vs outdoors, you’ll be able to begin growing both ways without the extra expense of buying plants. So give this list a good look, remember which seeds to never start indoors, and let’s get planting!
I would love to hear your thoughts / tips about sowing seeds indoors vs. outdoors!
Completely agree with all of the experienced gardeners posting here. Cucumbers and almost all squashes can be very successfully started indoors.
Sad that these articles are being written, and allowed to be posted all over the internet, with such conviction by inexperienced gardeners. Misinformation everywhere.
Hi Kim! I’m glad you stopped by and commented but I wish that you wouldn’t make the assumption that I just made a conviction filled statement out of ignorance. This whole topic of cucumbers and squashes not being great to start indoors is discussed by many “expert” gardeners including MIGardener, which is a very quickly growing gardening company. Doesn’t mean he’s right about everything but this shows that it’s not just me posting “misinformation.” If you are concerned still I guess you could reach out to him and the others who have the same concerns.
Thanks!
I always start my cucumbers, winter squash, and summer squash indoors and never have any problems transplanting (never lost a transplant yet!). I love being able to get cucumbers and zucchini and yellow squash in mid June – very early in my area. If I direct seed them outside, I do not get them until mid July – my overall harvest for the season is much greater since I get a jump start. I also always start all my lettuces indoors so when I transplant them outside, I can harvest them before the heat of the summer sets in. All my lettuces are cut and come again, but lettuce does get less sweet in hot weather. Definitely worth the effort.
I might have to try those! I have never had success w/ squash but I don’t want to give up. I LOVE it. Thanks for sharing your thoughts!!
All competitive growers start squash, pumpkin, watermeon, rutabaga(Swede), carrot, parsnip,often cucumber indoors and transplant. For the vining plants there is a need to know which way the vine is growing. For the others is starting time for getting a very long season. Hardening off and root bound is something to be very careful about.
There is an upside down, bottom cut out of 2 gallon water bucket(cut in half if you wish) method if you need larger plant to transplant. Place the top on a piece of plywood and duct tape it to the wood. Dig hole , put it in , cut duct tape and gently remove wood. Fill in hole and gently wiggle the bucket up. If you cut bucket in half do not forget to cut tape holding it together.
I have started beets, Squashes and lettuce in trays with very good success.
That is great! I guess there are always exceptions? What did you do to overcome these concerns or were they not a concern at all?
Sorry for so long to reply. I just got an email that someone new had added a comment and i thought i would take a look and i saw your reply to me. I did not know it was there until now. I never had a problem with any of them. But i do like to transplant my plants when they are still on the small side. Not real small but smaller than a lot of people do. They seem to take off better when small. On the beets i know several people that have started them in trays with good success. I usually put 3 or 4 of the beet seeds in each little compartment in the tray. When they have sprouted i make sure there is not more than 3-4 beet plants in each compartment. If there is i thin them to 3 or 4. They do just fine like that.
Thanks – great tips!
I disagree on the squash and cucumbers. I’ve been growing them from saved seed as transplants for several years. They are a little slow to “take off”, but do very well. All the others I plant direct.
Good article.
Hi there! That is so great you have had success with those! I got my information from all around the internet and with very experienced gardeners whom I work with (b/c I’m a real newbie!). You haven’t had any issues at all with them?
I planted some parsnips this year from seed and I started them sprouting in a plastic dish that was covered and I kept it inside my home.
When the seeds showed the root sprout I took them and planted them into a prepared box garden I had set up for them.
So far they are looking good!
That’s great you had success! I’m sure there are outliers to almost any rule—for examples I have a little “miracle cucumber” that I’m working on now. I removed it to thin it but it looks like it might make it anyhow, so we’ll see! I planted it to see how much it would grow. Hope it goes well for you! Thanks for reading!