How to start seeds indoors and everything you need for successful seed starting. Growing your garden plants from seed is a great way to grow more varieties and get more for your money.
This post contains affiliate links, which means I make a small commission at no additional cost to you. See my full disclosure here.
What do I Need to Start Seeds Indoors?
- Growing medium like seed starting mix or potting soil
- Pots or cell trays
- Light from either a bright sunny window or grow lights
Choosing the Best Seeds for Seed Starting
As far as favorites go, every packet of seeds has grown plants equally as great as the next. However, there are a few key things to consider when purchasing your seeds.
You can purchase seeds from big box stores, local farm/feed stores, online, or potentially from local farmers and gardeners. I am a huge proponent of Facebook groups for your local area and finding other people with similar interests to learn from. Ask around if there are local farm stands or shops where people are selling seeds.
Gardeners love to talk about their garden, growing plants, and seeds. Many gardeners would be more than willing to swap seeds with you or potentially share their seeds with you. It is always worth asking! I know I always have more seeds than I need and would love to share with people if they asked.
Growing your food from seed or even a started seedling from a nursery will always give you more value, variety, and nutrients than produce purchased from the grocery store shelves. Do not feel convicted if you have limited access or a limited budget for purchasing seeds.
Where Can I Buy Seeds Online?
Some of the places I commonly purchase seeds from are MIGardener and Baker Creek Seeds. Mi Gardener is extremely economical with low prices and smaller quantities, especially if there are new varieties you want to try but aren’t sure you want to grow a lot or you may not want to grow it year after year. Baker Creek Seeds has just about any variety you could ever imagine and they are all heirloom varieties, also at very fair prices.
I also commonly purchase seeds at Tractor Supply. Honestly, any store I go into that has a garden center or seeds for sale, is a potential place to purchase seeds. Get them where you can.
What Type of Growing Medium is best for Starting Seeds?
Many opinions are floating around about what growing medium is ideal for starting seeds. I am here to tell you not to overcomplicate it and not to stress over finding the perfect growing medium. Whether you use a sterile seed starting mix or a rough and lumpy potting soil, your seeds will grow. Seeds want to grow!
Seed Starting Mix
Seed Starting Mixes are sterile mixtures that are made to be extremely light and airy with no organic matter. The super fine medium is great for those fragile seedlings to shoot out their little roots and get started super quick. Because the seed starting mix is sterile, there is nothing in the mix for the seedlings to feed off of. If you start seeds in a mix like this and do not feed them with a fertilizer, about 10-14 days after the seedlings emerge, the seedlings will not grow and eventually, they’ll die.
Potting Soil or Other Soil Mixes
Potting Soil contains lots of organic matter that will feed your seedlings the nutrients they need to survive and thrive. The biggest drawback of using potting soil for starting seeds is the consistency of the soil. Potting soil tends to be more dense and tends to contain larger pieces of earth like dirt chunks, small rocks, and wood chips. This may present a challenge for those little seedlings and their fragile root systems. Personally, I have not had many issues using straight potting soil to start my seeds. However, my favorite way to start seeds is using a combination of seed starting mix and potting soil to get the best of both worlds!
What are the Best Pots to Start Seeds Indoors?
Your options are really endless when it comes to choosing a vessel to start your seeds in. Anything will work that can hold soil and drain water. There are a couple options that are ideal for seed starting, but don’t let it stop you if you don’t have the budget to purchase them.
Using cell trays are probably the most common way people start seeds indoors. Cell trays are trays with tiny little pockets you fill with your growing medium, and plant your seeds in. Because they are so small, the seedlings can only stay in the cell trays for two or three weeks before you need to up-pot and transfer them to a larger pot. You can find really inexpensive cell trays in the garden section at big box stores or at your local farm/feed stores.
These are my favorite cell trays I have used so far. They are slightly more expensive than the thinner plastic ones, but they are much more heavy duty and can be reused year after year. I also always make sure to label everything with these plastic tags as soon as its planted. You may think you’ll remember, but I never do.
If you want to avoid up-potting and transferring seedlings to larger pots so soon, starting your seeds into pots may be a better option. However, if you want to start the seeds in a seed starting soil mixture, this will be a little changing. Seed starting mix is much more expensive than regular potting soil. Filling up larger pots with seed starting mix will be costly. Additionally, as I mentioned earlier, the seed starting mix is sterile and will not feed your growing seedlings. This means you will have to be extremely vigilant with fertilizing your plants if they stay in the seed starting mix.
I love these pots because they are sturdy enough to last through the years, but they are slightly flexible and make it easy to squeeze plants out when getting ready to transplant them into the garden. A super rigid pot will make it challenging to pop plants out.
Over the years, I have used a variety of vessels to grow plants in. Red solo cups are fairly inexpensive and can even be recycled after use at a gathering. Make sure to poke or drill holes in the bottom for water drainage. They are, however, pretty flimsy and have not lasted more than one or two years for me. Cardboard egg cartons will work as well but tend to be pretty shallow and fall apart from watering.
How to Water Seedlings
Water is vital to the health of your seedlings. Seeds will not germinate without moisture. It is important to saturate your growing medium. It should mimic the texture of sand for building a sand castle. Wet enough to hold together if you grab a handful but not dripping. I prefer to wet the soil before adding it to the pots or cell trays. This way the seeds can go into the soil and not be moved around from water being poured on top.
Bottom watering is a great way to keep your seedlings moist without dousing their leaves in water (which can lead to disease and other issues). If you use cell trays, most will come with a tray for them to sit in and catch the water that comes out the bottom. This is also the perfect situation for bottom watering. Bottom watering simply means watering from the bottom, or pouring water into the bottom of the tray so the seedlings can soak up water through their roots, as they need it. This is how I water my seedlings.
As you outgrow the cell trays, you will need additional trays to continue bottom watering. I highly suggest purchasing heavy duty ones. If you are going to carry your seedlings outside to harden them off, a sturdy tray is essential. I use these trays and highly recommend them.
What Kind of Light do Seedlings Need?
Light can be tricky if you live in a northern climate where the sun doesn’t show itself until the end of spring. In my previous house, I had big south facing windows. Even through the Ohio winter and spring, we got plenty of sunshine to keep my seedlings happy in the windowsill. However, I was only growing about 20 plants that year and have since outgrown that windowsill.
Last year, I upgraded to grow lights and a grow shelf. There are some very fancy (and very expensive) professional shelving systems out there. Personally, I do not have the funds to purchase something like that just yet. My setup includes a metal shelf that I have had since college, and a couple sets of grow lights that I have added to as the years have gone by.
Do Seedlings Need Warmth?
Some seeds, like peppers, prefer soil temps to be warmer before they will germinate. Most seeds prefer warmer soil temps to cold ones. Because of this, I use heat mats to get the best and fastest germination possible. I have used several different mats and they all have worked equally great.
I only use heat mats for the first couple weeks after I start seeds indoors. After the seedlings emerge, they don’t need the heat mats any more. Because I start seeds at different points, I only have two small heat mats and just move them to whatever is being seeded at the moment. You don’t need to keep heat mats under all your seedlings for the entire time they are growing inside.
Growing Strong Root Systems
When you grow seedlings indoors, it is important to help them build strong roots for when they eventually get transplanted outdoors. To do this, it is good to have a fan on your plants. This creates movement and resistance in your seedlings to help them grow stronger. Additionally, you can run your hand lightly across the seedlings for that same movement and resistance building. That way, when the plants are outside in the wind, they won’t just snap in half. Keep reading for additional important information on getting your seedlings ready for life outdoors!
How to Start Seeds Indoors
If you are just starting out, you may not need as big of a setup as what I have discussed above. I highly recommend starting small and really diving deep into understanding how seeds grow and what kind of time and commitment it takes to successfully grow plants from seed, all the way through to harvest. I won’t lie, it takes a lot of effort and perseverance. Especially for those plants with very long growing seasons where you have to tend to the plant for months before ever seeing the fruit of your labor.
The Process of Starting Seeds looks like:
- Spend time over the winter dreaming of the varieties you want to grow and purchase your seeds
- Lay out the garden to determine how much space you have and how many plants of each variety you have room for
- Using a mixture of seed starting mix and potting soil, start seeds in cell trays according to the timing directions on the back of the seed packet (don’t forget to label!!)
- Set filled cell trays on heat mats and under grow lights for fastest germination
- Up-pot the seedlings after 2-3 weeks (after seedlings emerge) in the cell trays into 3 inch square pots filled with only potting soil
- Continue growing seedlings under grow lights until threat of frost has passed
- Watch 10-day forecast to determine my plant-out date
- Begin hardening off seedlings approximately 1 week before the plant out date
How to Harden Off Seedlings
Hardening off seedlings is just another way of saying getting seedlings used to the elements of the outdoors. When you start seeds indoors, they are protected from the elements. It is typically a fairly consistent temperature with fairly consistent waterings and feedings. The light stays consistent the whole time and there is no adverse weather for them to worry about. If you put a seedling outside without letting it get used to the elements, it may experience shock. This shock could kill the seedling or stunt its growth.
To harden off your seedlings, start with about 1 hour outside, maybe in the morning or evening when it’s not peak sunlight hours. The second day, try 2 hours. Each day, add another hour of time outside until they have spent the majority of the day outside. I am usually not extremely precise with this process. Sometimes I do 2 hours the first and the second day. Then maybe 4 or 5 hours the following days. You may have to skip a day if there is rain all day or other severe weather. The point is that it is not an exact science. Start slow and work your way up to more time outside. If you have to skip some days, that is okay. Don’t overcomplicate it, just do your best!
I hope this gives you the confidence to try to start seeds indoors. It is not too late to get started, even if you are a couple weeks behind the seed packet recommendations. If you are not familiar with reading seed packets, definitely start with my previous post: How to Read a Seed Packet. I walk through every item listed on seed packets, what they mean, and how to use the information to grow productive garden crops!
If you are feeling overwhelmed with the thought of starting your plants from seed, you don’t have to!! Gardening should be a joyful experience. Go to the nursery and buy plants already started for you. While I highly suggest trying to grow at least one plant from seed, don’t let the joy of gardening be stolen away if you are in a season of life where you don’t have the time or energy to start your own seeds. Do what you can and enjoy it!
If you are entirely new to the idea of growing a garden, start with my first post Gardening for Beginners. I go through planting dates, growing zones, frost dates, and which crops like to be planted in the spring, summer, and fall.
I hope you enjoyed this peek into Life at Metzger Acres!