How to Start Seeds Indoors

It’s seed starting time in Zone 9b! If you are a gardener on a budget or trying to be as sustainable as possible, starting your plants from seed is the way to go. A lot of people are intimidated by starting their seeds indoors. Perhaps you’ve tried it before, and you ended up with leggy plants or moldy soil. This post will teach you how to start seeds indoors without experiencing these struggles.

As with most things in my life, I’m not a purist about starting my plants from seed in any sense of the word. If I see a start that looks interesting or that I think needs rescuing, I’ll scoop it up without a second thought. BUT, 90% of our plants are started from seed.

I have a LOT of opinions about where you should order your seeds (FedCo is amazing, Johnny’s Seeds does business with Monsanto subsidiaries on and off) but I haven’t had time to write that article yet. Organic or heirloom seeds from your local nursery or hardware store are amazing! Seeds from the Dollar Store or WalMart are perfectly fine if that’s what you can get. 

Your Indoor Seed Starting Setup

This entire setup costs under $100. If that’s out of reach for you right now, it’s best to directly sow your seeds in a few weeks or buy starts. Trying to start seeds with just the light from a window is really difficult. 

Today, I have a greenhouse, but when I started I put my setup in my living room. It was not cute! It totally clashed with the decor, but it broke down very easily when seed starting season was over. 

Many people have great success setting up in their garage and using heating pads to help the seeds germinate. I’d forget to go out there and water and end up with a bunch of dead seedlings, but if you can handle the responsibility of out-of-sight plant care and don’t want to sacrifice the aesthetic of your home, go ahead and use the garage. 

The first thing you need is a metal shelf. Then you’ll need a fluorescent light for each self. Don’t be fooled by fancy grow lights, special lightbulbs, or other expensive things you don’t need. My fluorescent shop lights have served me wonderfully for over 8 seasons. 

In an ideal world, you would have two lights per shelf (side by side) ,but I did just fine with one for now, and so will you! The lights come with chains that you can use to hang them on the shelves. Once your setup is in place you are ready to start your seeds! 

Starting Your Seeds

I start my seeds using one of these little tray greenhouse things. Save it and use it for many years! I fill each pod with vermiculite. A big bag lasts me about 4 seasons. You could easily split one with a neighbor to cut costs. Vermiculite is lighter than perlite and creates the perfect environment for fostering healthy roots and happy plants.

I create a map for myself so I know what’s in each pod. Notice the tape on the tray. That’s how I match the orientation to the map with that of the tray. 

Once I have everything organized, I start planting seeds in the vermiculite. For larger plants like artichokes, squashes, and peas, I can get 2 plants per pod. For the smaller ones like leafy greens, tomatoes, and peppers, I can get at least 4 if not more.

Always plant at least 3 seeds in each pod. You won’t get a 100% germination rate (not all the seeds will spout), and this ensures you don’t have to start over. Once all your seeds are in, add water to the bottom of the tray until the vermiculite is wet but not soggy.

The tray full of vermiculite and seeds is placed on a seed warming mat. This is important to get those little seeds to sprout. They don’t need light at this point, but they do need warmth. If you are having trouble with low germination, I’d ask if your seeds are warm enough first.

I put the little greenhouse lid on crooked so we trap in some moisture but also maintain airflow. I’ve found if I put it on as it’s designed it causes the seedlings to mold fairly quickly. 

Remove the greenhouse lid as soon as your seeds begin to sprout. Lower the light so it’s just a few inches above the tray. This stops your plants from getting leggy (long weak stems). As soon as you can see two well-established leaves on your sprouts, it’s time to move them into bigger pots. 

Preparing Your Pots 

We buy milk in half-gallon containers. I’ve been cutting off the tips, drilling 3 ½ inch holes in the bottoms, and saving them for years. Once my seeds sprout, I up-pot the plants into the milk containers. If you need something to get you through this season head to the dollar store. They have two options for plastic seedling pots. Go for the bigger ones. See the photo below for why I use the milk cartons instead of plastic cells like many people do. These are the same seeds planted on the same date look how much bigger the one in the milk carton is!

Now you need some fine seedling soil. I have a recipe for that in a post here. I label my milk cartons with painter’s tape and a marker. Then I fill them with soil and place them in metal 13x9 cooking trays I buy from the thrift store. At this point, I’m ready to transfer my seedlings. 

Re-Potting Your Seedlings

The most important part of this process is to avoid breaking the roots when you transfer your sprouts into their larger pots. You’ve done a LOT of work to grow these beautiful (hopefully surprisingly long) root systems and we want to preserve that and keep it going. 

Use a sharpie or similar item to prepare a hole in each seedling pot. Push it almost to the bottom of the pot. You will need the space! Then gently loosen the root ball and vermiculite by pushing the seed pod up from the bottom. Grab the stem of the seedling and gently wiggle it out. 

Place it in your pre-dug hole and gently shake the pot to allow the soil to fall against all the roots. Then gently VERY GENTLY water your re-potted seedlings from the top. Make sure you water deeply. You want it to go all the way down to the deepest roots.  

If your seedlings fall over from too much water pressure just gently unstick them from the soil and help them stand back up. They’ll get stronger over the next few days as they grow more roots and leaves. 

Set your grow lights so that they sit just above your tallest plant. Now all you have to do is keep your seedlings moist (but not overwatered) and raise the lights as they grow. In about 8 weeks most of them will be ready to go outside. 

The reason for the 9x13 pans is so you can bottom water after your initial up-potting. I just fill the entire pan about ½ with water, and the seedlings suck up the water happily. It makes watering super fast and easy. 

If you have a problem with mold growing in your soil, a fan will solve this problem for you. I have a few clip-on ones I add to the shelves as needed. 

Happy indoor seed starting! This may seem like a lot of work, but it’s really just a few hours a few times and you will have more starts for your garden than you know what to do with. Look at the beautiful tomato start below. That's the quality of starts you can get when you use my indoor seed starting process.

If you have any questions at all send me a message on TikTok. I’m always happy to help.