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As a child, I learned at school one day that plants need carbon dioxide to grow.
I collected a soybean that had fallen out of my dad’s pocket (he’s a farmer, so it was not uncommon to find a corn kernel or soybean seed lying around), and I found an old clay pot of my mom’s.
I filled the pot full of “dirt”, planted the seed a few inches down, and watered the crap out of it. Then, I sat and talked to it, because I learned that as a human I breathe out carbon dioxide and by talking to a plant I could be giving the plant “extra” carbon dioxide.
Needless to say, the seed never sprouted.
Now, I know there are several factors involved in germination like depth of planting, moisture, temperature, aeration, etc. In this instance, planting too deep (I had a 12″ deep pot and planted the seed about 11″ deep–HA!) and using plain soil rather than a compost mix or soilless media (think potting mix or any of the other various mixes sold in stores) were probably major factors.
So, why start your own seeds inside?
I find that starting seed and transplanting works better for our flower farm and garden rather than direct sowing into the ground. You can control the environment better in an indoor setting.
The only flower farm-related plants that I direct seed every year are sunflowers because they are just so easy to direct sow. Also, sunflowers are large seeds, so they need more space.
Germination can be spotty when direct seeding plants. That’s because they are exposed to all sorts of fluctuations in moisture, sunlight, temperature, and pests. My transplants usually have a leg-up on pests and weeds when I plant them in the garden.
Starting my seed indoors also allows me to get a jump on the season so that I can have flowers blooming sooner or vegetables ripening sooner.
Overall, starting seeds indoors provides for a more controlled environment and healthier plants for me.
Basics of Seed Starting
Plant nurseries use various mixtures of compost, vermiculite, perlite, sand, peat, mulch/bark, and coconut coir to pot up or start their plants in.
The reason you don’t want to use plain soil (i.e. “dirt”) from your yard or garden is mainly because of aeration, drainage, and plant pathogens.
To explain aeration and drainage: After several waterings, the soil particles will start to compact, leaving few air spaces for roots to “breathe” (roots need oxygen!). Drainage will also be poor because undoubtedly your soil will probably have a lot of clay in it, and clayey soils do not drain readily.
The soil surface may crust over also, which will not allow water to readily percolate down through the pot. A good potting mix will be able to hold moisture but drain well enough that your plant is not growing in waterlogged conditions.
You also have to remember that soil contains not only minerals, but also living organisms, some of which can be harmful to a plant. By isolating these possible microbes in a pot, you may be creating the perfect atmosphere for plant pathogens to attack.
Left: A general potting mix containing peat and perlite (the little white rock-like substance). Middle: A seed-starting mix containing very finely ground peat, coconut coir, and vermiculite. Right: Vermiculite, a very light flaky silicate material that readily absorbs moisture.
When I’m starting my seeds, I like to use propagation trays that I buy on Amazon or at a greenhouse supply store like GreenhouseMegastore.com or BootstrapFarmer.com. You can also buy these trays in hardware stores at certain times of the year (usually the Spring).
You certainly don’t have to use these! I had to bump up my snapdragon starts a few years ago because the field wasn’t ready, so I transplanted into large clear dixie cups and poked holes in the bottom.
“Bumping up” is a term used when your plant starts start to outgrow their little cells or their container. In order to prevent your seedling from becoming rootbound and/or stressing the seedling, you’ll need to bump it up to a larger cell or pot size.
You can also buy pots or trays that readily decompose. They are usually made of peat or cow manure, but there are other types that decompose that are made of recycled plastic.
The important thing to remember if you are re-using pots or trays is that you need to wash them up really good! You don’t want some sort of fungal or bacterial pathogen to kill off your baby plants. I usually spray them off and scrub them with a dawn dish soap and bleach mixture.
These are a few things that you may need to start your own seeds indoors. Left: You can plant your seeds in any sort of container that works best for you. A seed starting mix is best, but you can improvise. Middle: A few other items you may need like saran wrap for covering your trays or pots to keep the atmosphere moist until your seeds germinate, vermiculite, a spray bottle for misting, and some labels. Right: This is an example of a seed-starting setup in my basement. I have 2 shoplights and a heat mat plugged into a power strip (click here to see the one I use) with a timer, so the lights will turn on and off automatically based on how I set them.
I have to share these awesome items from Bootstrap Farmer!
This is my first year purchasing from Bootstrap Farmer. I was looking for trays and pots that would last a long time. I’ve had issues with the plastic becoming brittle.
Let me tell you: These trays and pots are THICK. My last set of trays and cell inserts were much thinner, and they’ve mostly lasted me about 3-4 years. I expect these to last much longer, and I’m excited about it.
Here’s some of the products I’m using this year. Click the buttons below to shop for your own!
Shop Bootstrap Farmer Products Below!
Seed Size & Planting Depth
Seeds come in all sorts of shapes and sizes. A general rule of thumb is that bigger seeds need to be planted deeper, while smaller seeds can often be scattered on the surface.
The bigger seeds that I make sure to plant below the seed-starting mixture or soil surface are sweet peas, sugar snap peas, beans, tomatoes, peppers, zinnias, cosmos, and sunflowers.
Seeds that are really tiny that I scatter on the surface of my seed starting mix are snapdragons, amaranth, celosia, cockscomb, and lisianthus.
Some of these seeds are so tiny that I will moisten the end of a toothpick and pick up the seeds with the toothpick and place them on the media surface. The seed readily adheres to the moist toothpick, which allows me to pick up one seed at a time.
Another thing to remember about your little baby plants is that they need a nice balance of moisture.
When I’m starting seed, I fill my trays with moist seed starting mix and make sure the cells in the tray are filled evenly. Then, when my seeds are sown in the tray, I will cover the tray with Saran wrap or a clear plastic dome that holds the moisture in until at least 50% of my seeds have germinated.
After adequate germination, I will uncover the little seedlings and begin bottom watering or misting when the tray starts to dry out.
To better explain bottom watering: Usually I have a general 1020 tray (no holes) that I set my propagation tray (tray with channels or individual cells that have holes in the bottom) down into. I will use a watering can to pour about a 1/2 inch of water into the bottom of the 1020 tray. Then, as the seed starting medium starts to dry out, water will move up into the cells of my propagation tray as needed. This ensures that the seedlings are not disturbed or wiped out by overhead watering.
Left: A standard 1020 tray that you can find in most hardware stores during seed-starting season. Middle: A channel propagation tray (here’s a link to Johnny’s for channel trays). The channel tray will sit down in the 1020 tray. Each channel will have a different type or variety of seed started in it. Then, the seedlings will be transplanted into pots or a tray with individual cells. Right: Ornamental kale seedlings germinating in the channel tray.
Psst… Do you want to learn more about saving your own seeds? Check out our blog post about saving seeds by clicking here.
Another awesome option, especially for plants that need a cold period in order to germinate, is winter sowing.
The neat part about winter sowing is that you can use all sorts of containers, like plastic milk jugs or vinegar jugs.
Winter sowing involves planting seeds into a moist seed starting mix or potting mix and keeping the tray or milk jug outside throughout the winter. Eventually the seeds will sprout after they’ve had sufficient time to start the germination process, and this frees up your indoor space.
Winter sowing in milk jugs can be a great way to start seeds that need a cold period in order to germinate (click here for a marker that is great for labels or items that may be exposed to the elements).
When using the milk jug method, make sure to poke holes in the bottom for drainage and holes in the top for ventilation. Then tape them shut where you cut them so that the lids don’t flip open when you don’t want them to.
Some examples of flowers to start using this method would be: Bachelor buttons, larkspur, love-in-a-mist, echinacea, etc.
On a funny note: I tried winter sowing two years ago, but my milk jugs disappeared. Then, my mother-in-law, who lives across the field from me, said to me one day, “Butch was chewing on this milk jug full of soil in the yard. I don’t know where the heck that came from or why there was dirt in it!”
Butch, a big, lovable yellow lab, enjoyed coming to our yard to visit in the mornings to eat our scraps and make his rounds around the countryside. He was unfortunately hit by a car one morning while crossing the road to make his rounds, and passed away as a result of that accident. He was a mischievous, lovable oaf, however. On more than one occasion I caught him stealing things from our yard or the neighbors’. One time he stole a whole pie!
The task of starting your seeds indoors can be really daunting! It may seem like you need a lot of equipment to get started, but almost everything can be found inexpensively or can be re-used every year.
I like to start my seeds indoors because it allows my plants to have a jumpstart in the field. Without starting seeds inside, I would have much higher loss due to poor germination, pests, and weather.
Do you start your seeds indoors? What are your favorite plants to start early?
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