Starting Seeds Indoors - A Beginner’s Guide
Starting seeds indoors in late winter/early spring and transplanting them into your garden is certainly less convenient than buying seedlings from the nursery but the effort is paid back in spades. When you start from seed you not only spend just a fraction of seedling prices but you also are able to choose from a much wider variety of species and enjoy the magical process of bringing baby plants to life from scratch. You also save a lot of plastic waste! Germinating seeds is intimidating at first so we’ve broken down the process into bite sized chunks. Be aware that the first year you try this will be the most difficult but after you see those first plants safely transplanted into the soil you’re likely to become a germination addict!
SUPPLIES
Containers for starting seeds:
The most sustainable and best long term solution is to invest in a soil blocker. These nifty little hand-worked machines compress soil into tight little cubes that hold their shape, you can plant right into the cubes and then transplant them directly into the soil later on. Soil blockers come in a variety of different cell sizes and allow you the peace of mind that no plastic is leaking into your soil or plants. You can use a regular plastic tray or better yet a wooden tray to place the soil blocks into to catch excess water. Unfortunately, soil blocker supplies cost the most upfront and there are many other less expensive or free options to choose from below if you don’t want to go all in right away. I just found out about this method and haven’t bought my own yet to be able to recommend a brand but here is an example.
Germination trays are the classic option and the main one we use as we had some tray sets gifted to us a couple years back. These typically come as a three piece set including the bottom tray that catches water, the cell block tray you plant into and a clear dome that is placed on top for a greenhouse effect. You can get a variety of different cell block tray sizes- we use a 72 block size with cells 1.5 inches wide and 2.25 inches deep. This allows you to start a lot of seeds at once but you will need to transplant them into larger pots before they go into the ground so make sure you have space for that. You can buy sets like mine here!
Your third option is to use whatever small-ish containers you have on hand. We like to use the left over 4 inch pots from nursery seedlings (our clients are welcome to have some from our growing recycled collection for free, just ask!) and have also used yogurt containers and with holes poked in the bottom. You can place these in a tray or make DIY saucers out of container lids. If you use 4” or larger pots you can usually transplant the seedlings directly into the soil from there which is a plus if you are a lazier gardener, but it also means if a seed doesn’t germinate the pot will be taking up more space in the meantime than a small cell in a seed tray.
Soil Medium:
You can use any plain jane organic potting soil as your medium. We like the G&B organic soil found at City People’s, Swansons and Sky Nursery. Be wary of specialty soils advertising added fertilizers! When you get a couple seasons of germinating under your belt you may want to save money and make ultra rich soil by mixing the component yourself but let’s save that for further down the line…
Seeds:
One of the best parts about growing your seedlings indoors is you can pick out much better seeds than you can find at the big nurseries. Most of the local nurseries including Sky Nursery mostly sell plants from Monrovia, a huge company which like Monsanto, patents it’s seeds and reserves the right to sue you for taking cuttings or saving seeds. Many plants found at nurseries are also hybrids whose seeds are not viable for saving, this is done on purpose to make consumers reliant on buying more from the company. We highly recommend buying organic, open pollinated, heirloom seeds. This means the plants weren’t bred in a lab or genetically modified but refined over many generations of gardeners saving the best seeds and sharing them. You will be able to save your own seeds from the plants and not need to buy seeds again if you choose. You can also pick varieties that have been cultivated in the Pacific Northwest, making them specially suited to our environment. Here are our recommendations:
Adaptive Seeds - PNW based with open pollinated, organic seeds adapted to our northern climate
Seed Savers Exchange - Nonprofit with both heirloom organic seeds for sale and seed exchange open for trading seeds
Uprising Seeds - Small family owned farm. Washington’s first 100% organic seed company. Based in Bellingham!
Deep Harvest Farm - Over 140 varieties of open pollinated, organic vegetable, grain and flower seeds. Based on Whidbey Island!
Watering Apparatus:
Your plants are going to need water and a spray bottle is the best way to give it to them. Pouring water on germinating seeds or small sprouts can disrupt the soil and move the seed too far down to germinate or damage a tiny seedling. Using a spray bottle allows you to dampen the soil without upsetting your seeds. You can buy a fresh spray bottle or repurpose one if you wash it and as long as it never contained toxic chemicals!
Light:
You do not need to buy lights to start seeds indoors if you have a shelf or table under a window that gets a lot of light every day. However, you may still choose to set up lights because 24 hours of light will cause the plants to grow a lot faster than placing them under a window. Lighting set ups can be as simple or complex as your interest and budget. You can buy full package racks with moveable shelves and full spectrum florescent lights already fitted to them but this is going to be your most expensive option. If you want a cheaper option I would recommend finding a basic metal rack or even a wooden shelf at a thrift store or online and buying the lights separately. You can then attach the lights to the rack with chains and screw eyes (if you’re drilling into wood) and you’ll be good to go! Just remember that the further the tray is from the light the more leggy the plants will get as they strain upward, at the same time though you want to make sure you have room for bigger plants. If you are creating a permenant set up (instead of working with an adjustable one) I recommend doing a couple different heights between the shelves for trays of plants at different stages of growth. There are a lot of different light options to choose from online (you can also check Offerup or Facebook Marketplace to see if someone local has a set) but just make sure it’s either a full spectrum florescent light, such as the high output T-5 bulbs as they are closest to natural sunlight and use less energy than standard bulbs or a full spectrum LED which is even cheaper on electricity but not as similar to natural light. We got all our grow lights second hand and use a combination of different sizes and LED and inflorescent lights.
Labels:
Don’t make the mistake of not labeling your seeds and just hoping you will remember what you planted where! You can use wooden popsicle sticks or cut up yogurt containers (this is what we do) to make free labels. I usually just write on them with a regular sharpie but if you can find it the permanent/outdoor sharpies are less likely to fade if you want to use the labels outside later.
Starting Your Seeds:
I highly recommend starting this part outside as it can get a bit messy! I suggest doing this over your driveway or over another garden bed, remember not to use the tray at this time as it would only become completely full of water.
Whatever container you are planting into, fill it to the top with your soil medium.
Taking a watering can or even a glass of water or a hose turned to a trickle, soak the soil filled containers (not so hard the soil washes out though). The soil will sink down as it gets wet and the air pockets compress. You want the containers to be almost full (just a smidge below the top edge) when wet but not entirely as you don’t want water to overflow over the top when you water it later. If the soil goes down further too far, add more soil and water again until it reaches the desired height. Leave the tray for about 30 minutes so all the excess water can drain out.
Place your containers back on their tray or saucers. Using the tip of a pen or screwdriver, poke holes about a half an inch deep into the soil. If I’m using small container or germination tray I will only put one hole in each block or cell, if I’m using 4” pots I usually do two on the diagonal from each other but you could even do four- you would just then have to transplant some of them to other pots later.
Figure out what you’re going to plant and write the names on your labels in advance. I personally like to do entire rows as the same plant so I can use one label per row on my bigger germination trays but you may want only a few of each plant and need to label more or even all of them individually. Go in with a plan! I like to draw out my tray in my gardening notebook and write down my plan before hand as an added record I can refer back to the next year. Imagine each plant as fully grown- do you have room for 16 large tomato plants in your garden or do you really only need 8? Although I always say its better to have more plants than needed and give them away it’s still good not to go overboard and make extra work for yourself. 95% of your seeds will germinate. I also like to theme my trays by the types of plants going in them as they will be planted in the ground around the same time, such as a tray for nightshades, a tray for brassicas, a tray for herbs, etc. If you’re only doing one tray to start though you don’t need to worry about that!
Place one seed in each hole. You will be surprised how high the germination rates are on heirloom seeds, don’t make the mistake I did in my first year of putting two seeds in each hole and then having to separate tiny seedlings from each other and losing some of them! Be sure to label as you move to another seed variety,
Gently use the same tool you used to make the holes to push some soil back over them so the seeds are not exposed. Don’t compact the soil or the little seedling may not be able to push through.
The hardest part is over! Now simply put the dome on your tray (if you have one, I only have a couple and always do some with and some without, it’s helpful but not a make or break situation if your room is warm enough) and place it in the germination spot you have chosen. Whether it’s by a sunny window or under lights, make sure the temperature in the room is at least 60 degrees. If it’s less than that I highly recommend a dome to make sure the seeds are warm enough to germinate. If the room temp is lower than 50 degrees even a dome isn’t going to help and you need to find a warmer location or wait for the temps to rise. You also want the location you choose to have good airflow and ventilation. This will prevent damping off, a disease caused by fungi growing like a mold. I put a mini fan in my germination room for extra protection and to make the seedlings stronger and better able to withstand the great outdoors later on.
Maintaining Your Seedlings:
Every day (you can skip a day here and there if you have to but every day is best) grab your spray bottle full of water and spray each container/cell until a little bit of water starts to pool on the surface. For me this is 3-4 sprays each. If you’re not sure if you’re doing the right amount of water, it should be enough that the surface of the soil is still damp a few hours later but it dry again by the following morning. This might sound like a lot of work but it really only takes a few minutes and gives you the chance to witness the moment your seedlings poke up above the soil! This “chore” is often the highlight of my morning in the dreary late winter months. I love heading over to my grow station with my coffee and giving the plants some love before starting my day.
Keep spraying them every day even after the seedlings start to sprout. After the seedlings are significantly stronger you can experiment with pouring a little bit of water on them directly every couple days instead of spraying them every day. If it’s too early the seedlings will droop over or become unstable when you pour the water into their cell. If you don’t want to take that chance you can just stay on your daily spray routine.
If you started your seedlings in small cells they will eventually outgrow it and need to be transplanted to larger pots. I simply use a butterknife to slide along the inside edge of the the cell and gently pull out the plug of soil and sprout in one chunk and move the whole thing into a 4 inch pot. If you don’t have room under your light set up for the larger plants that take up more space, you can move some of them to a window. Now that they’ve gotten a good start the constant light won’t make as big of a difference. If you planted them in larger containers from the beginning you can skip this step.
When it is officially two weeks past the last frost it’s time to harden off your seedlings. Hardening off is the process of conditioning your sweet baby plants to the harsh realities of the outdoor world with it’s wind, sun, rain and colder nights. If you plant them directly from the controlled environment of your nursery to the soil some will live but some will die and you didn’t put in all this hard work for that! Over the course of 1-2 weeks, bring your trays outside in the morning on sunny windless days when temps are above 50 degrees and put them in the shade. Start with just an hour outside and increase by an hour or two a day until they are ready to go in the ground. The longer you take to harden them off the better guarantee that they will be acclimated.
After your plants have survived the gauntlet of hardening off they are ready to go into the ground! You can step back, brush the dirt off your gloves and let the smirk of a self-satisfied gardener creep onto your face (or do a little dance!) you just collaborated with the miracle of life and saved yourself a bunch of money at the same time!
