The Garden

8 Common mistakes when starting seeds indoors

Starting seeds can be exciting and gratifying if things go well and heartbreaking if they don’t. There are some definite mistakes you will want to avoid when you are starting your seeds! So let’s take a look at some of them and how you can avoid them so you can end up with a bountiful harvest at the end of the season.

Disclosure: Some of the links below are affiliate links, meaning, at no additional cost to you, I will earn a commission if you click through and make a purchase.

So hopefully you are super hella stoked about starting your seeds. If you are looking for different ways to start them you can check out 8 Ways to start seedlings for some ideas. This is one of my favourite parts of growing my own food. I love sitting down and planning out what I need/want to grow each year. I mean tomatoes are a given for my garden every year as I am tomato obsessed. I have more than 15 different types of heirloom tomatoes that I grow…so you can see what I mean about being tomato obsessed. I love making my own small batch tomato sauce, I do it weekly using whatever ones are ripe that week. So each batch has a little bit different flavour depending on what tomatoes went into it.

Heirloom tomatoes

Each year I find some new and wonderful types of plants to grow. Last year it was okra. Did you know that it has a flower that looks like a hibiscus? I didn’t until I looked out on my deck and saw it. After a bit of research, I discovered that it is part of the mallow family, which also includes hibiscus so it all makes sense.

Okra flower

I get most of my seeds from Baker Creek Heirloom Seeds as I only grow heirloom seeds (I have like a LOT of them). This year I have also started to really ramp up my seed saving. Do you save your own seeds? It really is an amazing way to save money and increase your harvests. If you want to learn more about seed saving, then this is the post for you! If you are curious why I made this choice, you can find out about my reasons here. Some of my new additions this year are:

That’s just a fraction actually, the list was getting really long and I am starting to think I need to join Seed Buyers Anonymous or something…is that a thing? I just can’t help it! I love growing things, thinking about growing things, watching things grow…sigh. I am happiest when I am in my garden that’s for sure. I went to Home Depot on the weekend and I saw that the garden center was open, so I walked in and literally did a happy dance. It was a bit embarrassing when I saw someone looking at me but hey I was really happy.

My dream chair

I also saw this chair, which is pretty much my dream chair. So I have to save my pennies so I can get it and add it to my back yard. I just picture myself curled up in it, reading a book and sipping on some fancy summer drink (most likely with alcohol in it). Looking up periodically to see if anything has grown. But anyway, that’s enough daydreaming for now. Before any of that can happen the seeds must get planted and grown successfully so let’s take a look at some of the issues and how to avoid them.

Not enough light

One of the most important things for strong seedlings is the right light. If they don’t have enough light or the wrong type then you will probably end up with “leggy” seedlings. Basically, they grow very tall, with thin stems and they are not very strong. The best thing you can do is to start your seeds under grow lights. You are going to want to keep the lights 4-6″ above the seedlings. Don’t let it get closer than that or you could end up burning your seedlings.

I have an Aerogarden grow light that is adjustable and I use it in conjunction with my seed germination heat mat. Whatever light you get just make that it is a full-spectrum bulb and if you can get an LED one then even better. Just make sure that you raise the lights as the plants grow. They are going to need 14-18 hours of artificial light per day, a good way to keep track of this is to set them up on a timer.

If you don’t have or don’t want to buy a grow light, then not to worry all is not lost. You can place them on a sunny windowsill, preferably one that faces south. If you find your seedlings are really leggy then you can always try and remedy the issue by repotting them. When you move them to a new pot make sure to get as much of the long stem under the soil but do it carefully.

This works very well with tomatoes as their stems can grow roots. Keep in mind not all seedlings take well to transplanting so this is the last resort. The best thing to do is to start your seeds with a grow light 4-6″ above them (make sure to move it as they grow) and you can put an oscillating fan in front of them on low. This will simulate the wind they would experience outside and will help their stems grow stronger.

Too much or too little water

Even if you give them heat and light, seeds won’t germinate and grow if they don’t have the right amount of water. Notice I said the right amount. Some seeds need more water than others but, as a general rule, plants shouldn’t be in soil that is too wet. Too much water can encourage the growth of fungus which is not what you want. Also, make sure that whatever pots you use have enough drainage in them. While too much water can be a problem, so can too little, a dried-out seedling is a dead seedling.

Planting too deep

Seeds can be picky if they are not planted in the right depth, they let you know this by not germinating. Some seeds need darkness to germinate (so they need to be planted deeper) and others need some light. Most seed packets will let you know the correct planting depth for the given plant. Heed this information and don’t just plant them however you want.

As a general rule, the bigger the seed the deeper it should be planted. If there is no planting depth on the package, or if you don’t have them in a package then aim to plant them 2-3 times deep as they are wide. Some seeds need a lot of light to germinate and they will just need to be pressed into the growing medium but not covered.

Starting them at the wrong time

Starting seeds too early or too late can put you at a disadvantage. If they are started too early and you don’t have big enough pots then they can become rootbound and stunted. This is not what you want as it can reduce your yields come harvest time. Starting them too late is not as bad unless it is going to push them into a potential frost before they come to maturity. One way to keep all the dates straight is to use a seed-starting guide. Lucky for you I have already made one that you can download here.

Using the wrong soil

Seedlings are not as hardy as mature plants, they are the babies of the plant world. This means they are going to be more susceptible to disease and illnesses. So using the right kind of soil will help to protect them. If not, they could fall victim to dampening off, which is a form of blight and one of the main killers of seedlings. Rather than using soil right out if the garden, you will want to use potting soil or seedling starting mix.

Forgetting about them

Don’t go putting them in a part of the house that you don’t frequent too often. They need to be watered daily and to be checked for any issues. This is especially key if you are just getting into gardening, it can be easy to forget them and then there is a good chance they will be dead when you next check on them.

I keep mine down in the laundry room on top of the dryer. My Aerogarden Farm Plus is down there already, so I am always down there (sometimes even to do laundry). So don’t go putting them in the spare bedroom if you don’t usually go in there. Seedlings are fragile and it can go bad in a day or two if you aren’t careful.

Not hardening them off

Growing seedlings and not hardening them off is like baking a cake and then throwing it in the garbage. Taking seedlings from the inside (even if you use grow lights) and planting them straight outside is a recipe for disaster. You need to give them time to acclimate to the very different conditions that exist in the real world. One thing that you can do to help toughen them up as they grow, place an oscillating fan on low in front of them to mimic the wind. You can also water them with a spray bottle to help mimic rain.

So while it does take some time it is a crucial step to a good harvest! If you want to know more about how exactly to harden off your seedlings you can click here for a detailed guide of the whole process.

Not enough heat

Seedlings require heat (and some cold) in order to germinate properly. Different seeds require different temperatures to germinate. Tomatoes do best between 10-35C and carrots do best at around 27C. In order to give them the heat, they need a seedling starting heat mat is a great investment. Some of the fancier (aka more expensive) models will allow you to change the temperature. Having the thermostat to monitor and regulate the temperature is key, otherwise, you could fry some of your seedlings.

Seed Germination Guide


  • Teti
    March 11, 2020 at 7:28 pm

    Perfect timing! Thank you very much for sharing!

  • Kylie Storer
    March 11, 2020 at 7:56 pm

    Some great tips here. From a complete novice who seems to kill everything I touch – thank you!!!

  • Katy Emanuel
    March 11, 2020 at 9:33 pm

    Our problem is often the too much water or not enough and then not hardening them off enough before planting. We have gotten our timing off too since moving to the Rockies since Spring starts and then winter returns a number of times in the spring before spring is here to stay. It is very unpredictable the weather making it a bit harder to judge.


Leave a Reply