As a child, I learned at school one day that plants need carbon dioxide to grow. So I took a soybean that had fallen out of my dad’s pocket somehow (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. (Side note: Soil nerds will say that soil is only “dirt” when it’s in a spot you don’t want it. And yes, I am one of those soil nerds.)
There are several factors involved in germination like depth of planting, moisture, temperature, aeration, etc. In this instance, planting too deep and using 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 operation rather than direct seeding. The only plants that I direct seed every year are sunflowers because they are just so easy to direct sow. I found that my germination was not as high when direct seeding some plants and the transplants had the advantage on pests and weeds. Starting my seed indoors also allows me to get a jump on the season so that I can have flowers blooming sooner. Overall, it provides for a more controlled environment and healthier plants.
Basics of Seed Starting
Plant nurseries use various mixtures of compost, vermiculite, perlite, sand, peat, mulch/bark, and coconut coir to pot or start their plants in. The reason you don’t want to use soil from your yard or garden is mainly because of aeration and drainage. Eventually, 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 sitting waterlogged. 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.
When I’m starting my seeds, I like to use propagation trays that I buy at a greenhouse supply store online. You can buy these trays in stores, and if you’re in the St. Louis area, I believe Hummert International also carries them in bulk. 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. 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.
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, 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 (see above picture of my red watering can) to pour about a 1/2 inch of water into the bottom 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.
Gathering or Saving Your Own Seed
Fall is a great time to collect seed from most plants because the plants are done flowering and the seedheads have begun to dry out. If you pay close attention to your surroundings, you may be able to find seeds for some really neat native plants.
The important thing to remember when saving seed is to collect from multiple plants in a single population if possible. This helps preserve genetic diversity, especially if you are going to continue saving seed from the plants that you germinate. Eventually, if a single population of plants continue to cross with only each other, you’ll see reduced vigor. There are many great resources out there that specifically talk about saving seed. You need to be wise with collecting and propagating seed from the wild, however. In some states it can be illegal to collect off of roadsides and you need to make sure you are not propagating a plant that may get out of control because of its invasive nature.
Top left: Multiflora rose hips. Inside the red skin will be a seed. This is an example of an invasive species that you should not try to propagate in your own yard… It will quickly take over. Birds, however, love to eat the hips. Top middle: Bee balm seedhead. Top right: Morningglory seedhead. Bottom left: Seeds inside the morningglory seedhead (Side note: These are horribly weedy plants). Bottom right: Notice the fluffy parts of these aster seedheads. At the end of these pieces of fluff is a seed which will blow away in the wind. Most of the seeds have already blown away on this plant.
Some seeds that are saved from certain plants, specifically hybrid plants, will not be true to type, so be aware that your baby plants will not always look like the mother plant. This could be due to cross-pollination or due to self-pollination and the inherent genetic diversity held within that particular plant. Again, there are many great resources out there that will explain the science behind plant genetics.
Another awesome option, especially for plants that need a cold period in order to germinate, is winter sowing. This is when you plant seeds into a moist seed starting mix or potting mix and keep the tray or, in the case below, 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.
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 plants to start using this method would be: Bachelor buttons, larkspur, love-in-a-mist, etc.
On a fun note: I tried this 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’.
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Not interested in starting your own seed but would love to have a cutting or vegetable garden? We’d love to help you out with that as well! This year we will be starting some heirloom or unique veggies and flowers from seed specifically to be sold as plant starts, so stay tuned into our Facebook or Instagram page to learn more about what we will have to offer!