When the end of winter nears and the thoughts of spring are looming overhead, the stress of starting flower (or vegetable!) seeds can begin to feel overwhelming. While I’ve had my fair share of seed starting failures, I think I may have finally figured it out! In this post, I’m going to walk you through the importance of each item from growing medium to lights!
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Start with the soil (or not)
Regardless of what you’re trying to grow, having the correct growing medium is the most important thing you need.
Compost alone is not enough to guarantee optimal germination or seed growth. If you are making your own seed starting mix, be sure to sterilize compost by placing a thin layer in the oven at 250* until the soil reaches 180*. Don’t overheat as it will cause the breakdown of essential nutrients.
Vermiculite is also an extremely beneficial component of any soil medium. While the name sounds scary, it’s really only ground-up rocks that are heated until they pop like popcorn. This allows the rocks to hold on to a ton of water and also allows aeration for the roots of seedlings. Although vermiculite is able to be used on its own for starting seeds, it isn’t recommended. Vermiculite contains zero nutrients meaning sprouted seeds would need to be transplanted into another growing medium. Who has time for that?
Like vermiculite, perlite has its place in seed starting as well. Instead of rocks, perlite is made from volcanic glass that is heated until it pops much like vermiculite. Additionally, perlite is more porous allowing for better drainage and aeration. Used together, vermiculite and perlite help maintain moisture levels to prevent disease and root rot.
Coconut coir fibers are becoming increasingly popular as soil amendments and seed starting medium due to their superiority over peat moss by providing soil stability, water absorption, and drainage, and sustained fertilization. Being naturally free from disease, coconut coir reduces the chance of disease or pest infestations.
Pots or Trays? Which is best for seed starting?
Both! Using what you have on hand is always an acceptable option as long as there is the ability to have a drainage hole in the bottom. Seeds that need a longer time indoors usually do better in a pot. For instance, dahlia’s transplant better once the plant has reached between 8-12 inches. To prevent root disturbance, a larger and single container is optimal.
Trays are widely used for seed starting and it’s no secret why! Having smaller cells on a tray not only allows for mass germination but also saves on space. When operating a small or micro-farm, space is everything! Flowers that require 4-6 weeks of indoor growing do best in trays.
When plants are beginning to grow, it is important to water them from below as top watering can lead to disease pests. The best way I found to make this work is to place trays on top of a medium to large dog crate tray. The crate tray also makes the seed trays more stable on top of heat mats. Yes, heat mats!
Why start seeds indoors anyway?
The reason why seeds are started indoors in places such as New England and Canada is that the growing season doesn’t begin until much later than in other locations. In order to allow plants to make it to harvest, seeds are started under conditions that would be similar to growing outside. The easiest way to do this is by using a heat mat that is able to maintain a constant temperature.
The above picture is my current setup. As you can see with the plants being propagated, the amount of space available for seed starting is precious! Hanging above the bottom shelf is a shop light with a plant/aquarium light bulb that emits specific colors that promote better growth. As the growing season gets started, I’ll replicate that set-up on the other shelves.
Looking for guidance?
Beginning the second week of February, I will be beginning the seed starting process. If you’d like to follow along, I’ll be sharing all the juicy details in our weekly newsletter. Newsletters, not your thing? I’ll be sharing in Insta-Stories, too!
To get you started, recommended supplies are listed below. My personal favorites and the ones we use will be linked! Don’t forget to download the checklist, too! Getting organized is key to seed starting success!
- Seed Starting Medium and Amendments
- Coconut Coir
- Pre-mixed Seed Starting Medium
- Trays and/or Individual Pots
- Dog Crate Tray
- Heat Mat
- Shelving and/or open space
- Grow Lights