When you’re new to gardening, starting plants from seed might sound like an intimidating task. At least it did to me. Seed starting just looked like a lot of work that required the kind of gardening skill only master gardeners would possess.
But I moved out to my husband’s farm and was forced to face my seed starting fears head on. It turns out that seed starting is really not that difficult. You can do it, and I’ll show you how.
Step One: Gather seed starting supplies
1.Seed starting mix
It is of utmost importance that you use a fine grain seed starting mix, aka germinating mix, to start your seeds. Potting soil and garden soil are too dense and contain sticks and debris that you don’t want when you’re starting seeds.
Germinating mix is usually available at garden centers, but can be hard to find if it’s not early spring. Learn to make your own seed starting mix in my book, Seed Starting For Beginners.
2. Seed Starting Containers
We use multi-cell seed starting trays with clear dome lids which are great for starting 50-100 seeds at a time. If you’re not ready to do that many at one time, try these 10 Ideas for Upcycled Seed Starting Pots.
For a home gardener, I like this seed starting kit which includes the plastic cells, a tray they sit in, and the dome which traps heat and moisture. Here is seed starting kit that includes all of that plus a heat mat which I will talk later in this post.
Before you start planting, make sure you have a way to label your seed starting containers. All the little seedlings are going to look the same, and if you have any plans to save seed you need to know the name of the variety you planted.
Just choose something small and waterproof. This is not the time for the pretty garden markers. You’ll use something prettier when you plant it out.
Find out my favorite super cheap way to label seedlings in Seed Starting For Beginners.
Hopefully, soon, you’ll be saving your own seeds, but for any you don’t have, choose your favorite seed supplier. I love Seeds for Generations, Baker Creek and Johnny’s, but there are tons of seed suppliers out there. Hey, even Wal-mart has seeds.
Don’t worry too much about which seeds you choose. Yes, there are differences between heirlooms and hybrids, but both should be welcome in your garden.
As a home gardener, you can not buy GMO seeds from seed suppliers…yet. They are only available for sale, usually in bulk, from the manufacturer of the seeds.
Want suggestions on what to grow?
Your seeds need to be warm and cozy if you are going to coax the little baby plant out of them. Appropriate germination temperatures vary by type of plant, so check your seed packet for ideal germination temps.
The best way to keep them at the right temp is to put them on a seedling heat mat with a thermostat. This is not the same thing as a heating pad. Don’t use a heating pad.
You can purchase a heat mat on Amazon for around $20.
In a pinch, you can rest your seedling tray on top of your refrigerator. This should get you pretty close to the right temperature for germination for tomatoes and peppers. But, just in case, I would plant a few extra since you can’t regulate the temperature very well up there.
Step Two: get the seed starting mix into your trays
Pro tip: Water the germ mix before you fill the trays.
Damp germ mix is easier to work with, fills your containers more evenly, and prevents dry patches in the cell.
You’ve got the right amount of moisture when you squeeze the germ mix in your hand and it holds its shape but is not soggy.
To get the damp germ mix in the tray cells, spread the dirt loosely on top until all cells are filled. Don’t force the mix into the cells, you don’t want the soil tightly packed in the trays.
Here we have five trays ready to plant. Hubz is dibbling which just means poking holes for the seeds. He’s actually using an old nail head, but a pencil or pen is just the right size, too. Let the kids use their fingers. Or just grab whatever is around you.
It is not necessary to dibble before starting seeds. You can also rest the seed on top and then push gently on it with your finger to set it in. However, if you are working outside on a windy day, we recommend you dibble then drop and not the other way around.
I just want to say dibble one more time. And now I’m done.
Step Three: label then plant seeds
I recommend labeling your tray before you start putting in seeds and working one variety at a time.
It is very important to go in that order. If you get distracted and forget which seeds you have started or which cells they’re in, you could be in a mess later. Many seeds are very, very tiny and you very likely will not be able to see them once they’re on the dirt.
Step Four: cover seeds
When all seeds are safely poked into their new homes, cover lightly with loose germ mix or use vermiculite and sprinkle it on top.
Vermiculite is a naturally occurring mineral that is mined and shredded to form the product we use in the garden. It is very light-weight and super absorbent. Seed babies easily push up and through vermiculite at germination.
When planting tomato seeds, we place one seed per cell. There are some reasons you would plant more than one per cell. If you aren’t sure of the viability of your seeds or can’t control their temperature and hydration definitely plant 2 or 3 per cell.
If you plant more than one per cell, and they all sprout, you may need to pick the strongest sprout and pluck the others.
Look at these trays of basil plants. See how many tiny plants there are per cell? With basil and many other herbs with tiny seeds, we sprinkle seed onto the germ mix and lightly cover with vermiculite.
As a side note, a lot of herbs do well when directly seeded into your garden, but make SURE the chance of frost has passed.
Step Five: water the seeds in
Once the seeds are safe in their new homes and cozy in their vermiculite blanket, water them well, but you don’t want them soggy. They will rot or mold if there is too much water.
Step Six: taking care of the seedlings
All you have to do is keep them warm and watered. We recommend using a tray with a clear lid to trap moisture and retain heat.
These trays are sitting on a 48″ heat mat and under two fluorescent grow lights.
Tomato and pepper seeds don’t need light to germinate. But the light provides some warmth, and they will need some light when the seed pops (pop=germinate=sprout) so you might as well go ahead and set them up.
You don’t need lights, you can use a window. However, seedlings grown in a window are prone to stretching which can create a flimsy, wimpy little stem.
Also, baby plants are very tender and fluctuations in temperature, as can happen in a window sill, can kill them. Investing in a heat mat and a light kit is really worth it. You’ll get a much higher germination rate and sturdier plants.
It will take 5-10 days for tomatoes to sprout, peppers can take up to 14 days, and most herbs will germinate after 5-7 days. Older seeds may take longer. Fresher seeds may be shorter.
Germination times and temps are included for many commonly grown food crops in the ultimate garden planning spreadsheets. They also calculate your germination rates so you can keep track of which plants are growing best for you.
If your seeds don’t come up, there are a few steps to figuring out what went wrong. Learn how to evaluate a low germination rate.
These little guys were planted 6 days before this picture was taken. Aren’t they just so cute?
Seedlings are very tender, and they’ll need daily attention to keep them healthy.
Make sure you check on your seedlings every day. They are very susceptible to drying out, and they will die if you forget or ignore them.
I’m sure you have lots more questions like:
How long do the seedlings stay on the heat mat and in the greenhouse?
What if they outgrow the starter tray?
Do my seedlings need fertilizer?
What is hardening off?
When should you plant them out?
Find the answers to all of these questions and more in Seed Starting for Beginners.
How long until my seedlings produce food for me and my family?
It feels like forever, but really it takes about 3-4 months to get from seed to fruit. That is an excruciatingly long time, but oh the joy of your first tomato from the garden. It is a delight every single year.
A green tomato takes approximately 60-90 days to ripen on the plant. Seed to tomato definitely takes 3 to 4 months.
Herbs like basil, cilantro, and thyme can be harvested for leaves at around 6-8 weeks or whenever they have enough leaves to spare a few.
Peppers take about 90-120 days from seed to produce ripe fruit.
Once you get the hang of starting your plants from seed, you’ll find it hard to go back to buying plants. You don’t get anywhere near the variety of options by buying plants from the nursery. It’s so much less expensive, and it’s really not hard if you set yourself up for success by following these steps.
If you’ve had trouble with seed starting before, then I recommend you read my seed starting for beginners book. It’s full of much more information about what you need to do and why, the two most important factors for getting good germination, and everything you need to know about caring for your seedlings after they sprout.