Gardening Sowing Seeds Vegetables

Beginner’s Guide to Sowing Vegetables Indoors

Photo: homegrown-garden.com/blogs

That’s it: you’ve made up your mind. This year, you will be starting your own vegetable seedlings for the summer’s garden. You’re going to start from scratch, with a packet or two of vegetable seeds, like a pioneer. Yes, you are a Victory Garden 2.0 garden pioneer. Give yourself a medal! 

Now, you’ve never sown seeds before, but last year you saw half of your neighbors jump in and grow their own vegetables from seed, then harvest delicious, fresh fruits of their labor from the garden over the summer. They even shared their surplus veggies with you (pioneers do that!) And starting plants from seed didn’t seem so difficult…

And it isn’t, either. It’s even so easy that sowing seeds indoors in pots is commonly taught in kindergarten! Hey, if a 5-year-old can do, so can you!

Start E-A-S-Y!

But there is a little secret: you have to start with easy varieties, such as cucumbers, tomatoes and cabbages. (Other suggestions appear in the table below.) Pick only fast-growing plants, ones that will give results in a very short time. You don’t want to start with apple seeds that will take at least 10 years! That might stretch your patience! First timers deserve results fast, fast, fast! 

Fortunately, it is precisely the fast-growing plants that are found in most commercial seed packets. So, everything is lining up for the best! This has to be karma!

Which Seeds Should You Start Seeds Indoors? And Which Outdoors?

True enough, you don’t always have to sow vegetable seeds indoors. Some do better when sown directly in the ground where they’ll be growing. And it’s even easier that way, requiring way less handling on your part. 

And with some vegetables, you have a choice: indoor sowing gives them a bit of a head start on the season, but outdoor sowing is perfectly possible too. For example, in some regions, it makes sense to start seeds of salad greens indoors to get an early crop, and then sow more of the same greens outdoors to extend the growing season.

But then you have vegetables that are clearly in the “always sow me indoors” category, where an indoor start is mandatory in most climates. Otherwise, they ripen far too late. That includes such popular vegetables as tomatoes and peppers … and you wouldn’t want to miss out on growing those! So, use the information in the table below wisely.

Seeds to Start IndoorsSow Indoors or OutSow Directly in the Garden
Artichoke
Asparagus

Basil
Broccoli
Brussels sprouts
Cabbage

Cauliflower
Celery
Eggplant
Ground cherry
Leek

Okra (gumbo)
Onions
Peppers
Tomatoes
Chicory
Cilantro (coriander)
Cucumber

Endive
Kale
Lettuce and salad greens
Melon

Parsley
Spinach
Squash
Swiss Chard
Arugula
Bean
Beet
Borage
Broad bean
Carrot
Corn
Dill

Parsnip
Peas
Radish
Rutabaga
Sunflower
Turnip
Seedlings that are particularly easy to sow indoors are shown in blue. The ones in black … a little more challenging. Maybe next year? But leave the vegetables in red, which are much more difficult, for when you have a few years of seed-growing experience under your belt!

A Few Things to Buy

Materials needed for sowing seeds indoors: seed starting mix, soil, pots, trays, etc.
You can often recycle containers for seedlings, but you always need good, fresh seed-sowing mix.

? Growing veggies from seed doesn’t require much of a financial output. Sure, maybe later, as you become an old hand at sowing, you might want to invest in grow lights, but for this first time, let’s make this a low-budget project. And you’ll be harvesting far more in value—all those delicious fresh vegetables you’ll soon be munching on!—than you invested in the launch. But there are still going to be expenses.

To start with, you need seeds. You can find packets of vegetable seeds in garden centers or hardware stores, on the Internet or in a catalog. 

Also, you need a seed starting mix, pots plus one or more trays with matching transparent dome. 

Of these, you really only need to buy the sowing mix. (Do not use soil from the garden for seeds: that’s an invitation to disaster. Seed sowing mix is fairly sterile, and you what things fairly sterile when you start seeds indoors.)

As for pots, sure you can buy them, Mr. Money Bags, but the thriftier among us will recycle pots (almost any small plastic container with a drainage hole punched in the bottom will do). As for trays and domes, those clear plastic trays you buy produce and pastries in at your local supermarket are just perfect!

When to Sow

You need to figure out the right date to sow each seed, according to your local conditions.

So, you’ve decided to sow tomatoes and cucumbers indoors for your first seed-sowing experiment. (Two batches of seedlings are plenty for a first time, remembering you can later sow other vegetables directly outdoors. You can try more when you have more experience!)

This is biggest mistake beginner gardeners make sow them too early! That actually decreases the yield! Just don’t do it! 

?? Important Note 

The reason this article appears so early in the season (February) is so you can prepare for your seed-sowing activity in advance. In most climates, that’s at least one month earlier than you actually have to sow anything. The majority of seeds are sown sometime between March and May: rarely in February! 

Obviously, there isn’t going to be “the day” when you sow all your seeds at the same tie. Some need an earlier start than others. And the date will vary according to your climate. (Florida gardeners will be starting their seeds earlier than Yukon gardeners.) 

All your seed sowing needs to be based on the last frost date in your area. You’ll be sowing your seeds according to a given number of “weeks before the frost-free date.” Ask another gardener what the local frost-free date is. Or ask at your local garden center. Mark it permanently on your electronic agenda. 

Back of seed packets showing dates for sowing.
Often the recommended date for sowing is indicated on the seed packet. Photo: laidbackgardener.com

The ideal sowing date varies from plant to plant. To find it, look on the seed packet or on the Internet, in a book or in a catalog. Or try this handy Seed-Starting Date Calculator from Johnnys Select Seed. Remember, each vegetable has its own preferred sowing date.

With this information in hand, you’ll know exactly when to sow!

How to Sow Indoors

That’s it! You found the date for starting tomato seedlings in your area is between April 4 and April 25 and that date has arrived, you have your seeds and materials on hand and you’re now ready to take the first step.

Here’s what to do:

  1. Pour seedling mix into a bowl or bucket and add lukewarm water. Stir until the soil is uniformly moist, not wet: like a wrung out sponge.
  2. Spoon the moist mix into pots about 3 inches (7.5 cm) in diameter and even the mix out with the back of a spoon
  3. Check the seed depth on the back of seed pack, on the Internet or in a book. (If this information is not available, calculate a depth equal to three times the diameter of the seed.) With a pencil or pen, poke a hole of the corresponding depth in the sowing mix, right in the center of the pot.
Drop 3 seeds into the sowing hole.
  1. Drop three seeds into the hole (always sow more seeds than necessary in case germination is poor).
Sow and spray.
  1. Fill the hole with soil and spray with lukewarm water to settle the sowing mix
  2. Insert a label with the plant’s name and the date you sowed it. 
Pots of seedlings in a tray.
Cover the pots with a transparent dome.
  1. Place the pots in a waterproof tray and cover them with a transparent dome.
  2. Place the tray in a warm spot: about 72 to 75 °F (21–24°C) with good light, but avoid direct sun at this point. 

After Germination

Squash seedlings on a windowsill.
Place the tray in a very sunny location. Photo: Pexels
  1. After germination, i.e., seed sprouting (which can take from 3 days to 3 weeks or even more, depending on the plant chosen), remove the dome. 
  2. Move the tray to a very sunny location (in front of a south-facing window if possible). 
  3. If more than one seedling emerges per pot, remove the weakest ones, cutting them off with scissors, leaving only one plant per pot. (This is called thinning.)
Pots of seedlings that soak in water from a tray.
Water the seedlings by soaking them in lukewarm water.
  1. Keep a close eye on watering. When the soil goes from dark brown to pale brown, that means it’s dry: time to water! Pour lukewarm water into the tray and let your seedlings soak up the water they need, then empty any surplus.
  2. When 4 to 6 true leaves appear, begin fertilizing every second time you water with a soluble all-purpose fertilizer at one quarter of the recommended dose.

Acclimatization

Seedling trays in acclimatization.
Acclimatize seedlings to outdoor conditions. Photo: jardinierparesseux.com
  1. When the outside temperature warms up and there is no more risk of frost, acclimatize your seedlings to outdoor conditions, putting them in the shade for 2 or 3 days, then in partial shade for 2 or 3 days and finally, finish hardening them off by allowing them 2 or 3 days in the sun. If the temperature suddenly cools off during this period, put them a garage or shed overnight.

Planting Out

Hand planting a seedling in the vegetable garden.
Transplant your seedlings into the ground or a pot … and soon reap the fruits of your labors!
  1. Transplant your seedlings into their final spot, either in the garden or in a container, and water well.
  2. Throughout the summer, water and fertilize your plants according to the needs of an adult plant.
  3. When your vegetable is mature, looking full and luscious, get out there and harvest! And make sure you share your surpluses with your neighbors so they now know that you too are a gardener!

The illustrations accompanying this post are from the book Les semis du jardinier paresseux by Larry Hodgson

Garden writer and blogger, author of 65 gardening books, lecturer and communicator, the Laidback Gardener, Larry Hodgson, passed away in October 2022. Known for his great generosity, his thoroughness and his sense of humor, he reached several generations of amateur and professional gardeners over his 40-year career. Thanks to his son, Mathieu Hodgson, and a team of contributors, laidbackgardener.blog will continue its mission of demystifying gardening and making it more accessible to all.

4 comments on “Beginner’s Guide to Sowing Vegetables Indoors

  1. Pingback: My Sowing Kit (or Ode to the Mushroom Tray) - Laidback Gardener

  2. Pingback: Starting Seeds in Zone 1b – Grandma's Prairie Garden

  3. Artichokes and asparagus are two vegetables that I do not minding purchasing as pups. Well, I do not grow asparagus, and only a few artichoke pups are needed. There is not enough space for many.

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