4 Tips for Growing Great Seedlings
Want to grow awesome plants? Vibrant green leaves, sturdy, and bursting with enthusiasm to grow as soon as you put them in the ground? Here are a few things I do to ensure excellent backyard nursery plants.
1. Use a Good Soil.
Use a good quality potting soil. Choose organic options if you can. I like a good balance of organic matter/compost that is also somewhat light to keep that balance of air and water-holding capacityin your soil for your beneficial microbes to thrive! It should hold its shape slightly when you squeeze a handful of the soil, indicating it’s good at holding moisture. Coast of Maine and Vermont Compost both have some great potting mixes when I was in New England. Both have peat moss. Peat moss is an excellent soil conditioner, but the sustainability of the peat moss industry has been coming into question more and more over the years. The Organic Mechanics Soil Company is a company I recently heard of that produces peat-free potting mixes. I’ve heard good reviews but haven’t tried them yet myself. You can also mix your own, though it can be finicky to get the balance right. For instance, if you are using your own compost, some people recommend spreading it out to dry first before mixing with it light materials like peat moss, perlite or coconut coir to help avoid bacterial or fungal issues like “dampening off” that reduce your seedling success. If you’re new to growing plants or just want to ensure consistent results, I’d recommend starting by getting a quality potting mix.
2. Add Beneficial Biology.
Just as adding probiotics is good for a healthy human gut microbiome, adding beneficial microbes to your new seeds and seedlings is great for your plants. It is essentially like adding an immune system booster to your plants helping them be more resilient, better utilize nutrients in the soil and access water. There are several ways you can work to add more beneficial biology to your system. I use a mycorrhizal seed inoculant that I sprinkle directly onto seeds or onto roots when transplanting an already established plant. Choose inoculants that have a wide diversity of bacterial and fungal species. A little pinch can go a long way: 1 ounce is often enough to inoculate 100lbs worth of seeds! There are many options out there. For example, I’ve used Advancing Eco Agriculture’s “BioCoat Gold” inoculant and Fedco Organic Growers Supply’s “MycoApply Endo/Ecto” inoculants with great success.
Another easy way to get super charged with incredible microbial benefits is by using worm castings (aka: worm poop!). I knew worm castings were beneficial to transplants already, but I had not realized how unbelievable the results could be until I watched Monique Bosch’s presentation on harvest yield differences using worm castings (resource link below) vs. not using them. Since then, I have started incorporating home-produced worm castings into all my plantings and have seen my plants reach another level of health and production.
There are many ways to introduce beneficial biology to your soil! Introducing wild strains of beneficial biology is yet another way to do this. If you are planting your own blueberries, for instance, consider taking a handful of soil at the roots of healthy wild blueberries in the woods and add it to the base of your new plantings! The soil is teeming with life and all you have to do is introduce some of that diverse biology that has been cultivated over time by the wild plant to your own planting to improve your own plant’s health!
There are many ways to add beneficial biology to the soil, seeds and plant roots. Pick several or simply just try one. Consider a side by side trial to see what really is making a difference. Biological diversity is notoriously hard to measure, so prove it to yourself which methods work best for you and your plants!
3. Use Micronutrient-Rich Amendments.
Ensure that the soil is full of both macro and micronutrients that the plants can access (with the help of their microbial partners, of course, that literally EAT rocks on the plants’ behalf!). We used to think that plants only really needed N-P-K (Nitrogen - Phosphorous - Potassium) to thrive, but as our understanding of the soil has deepened, we just keep adding more essential nutrients to that list…Sulfur, Calcium, Magnesium… oh, and these are kind of important too… Boron, Copper, Molybdenum, Manganese, Selenium, and the list of “essential” keeps getting bigger! Some of these nutrients are ABSOLUTELY essential, but only needed in tiny amounts. Some soils are naturally rich in these trace elements while others aren’t. It all depends on what type of rock the soils are formed on and how much weathering and leaching and rainfall has happened in that region. I like to ensure I add a blend of micronutrients that the plants can access if they need it. I do this by adding rock dusts, mineral fertilizers and micronutrient-rich materials like seaweed that have lots of trace elements to feed to the soil microbes in your soil. The microbes will work with the plants to get what is needed, but only if those mineral elements are present in the soil mix.
The following amendments are often in all-purpose organic fertilizer mixes so if you want to keep it simple, just add an all-purpose organic fertilizer blend like “Pro-Gro” from North Country Organics or the vegetable garden mix from Epsoma. Good micronutrients sources include sea minerals and sea products like kelp meal and seaweed extracts, volcanic deposits or granite rock dusts like azomite, carbonatite or rock dusts leftover from quarries, redmond sea salt, soft rock phosphate, marine deposits like greensand, or wood ash. I typically mix some combination of the above amendments and add 1-2 cups of this blend per 4ft x 4ft garden bed OR add it directly to my compost bin.I’ll share my specific recipe for the nutrient dense blend that I like to use in a future post!
4. Minimize Plant Stress.
The more the plant has exactly what it needs, the better it’s health. That means deep enough containers for roots to grow. If you do plant seedlings in very small containers, make plans to get them in the ground sooner if you can. Plants produce roots like scaffolds underground in the soil. If the plant is stressed in any way, it’s underground root “scaffold” will be smaller, produce less tiers, and the plant aboveground will correspondingly be smaller or produce less fruit. The first few weeks of a plant’s life heavily affect the plants’ ultimate potential to produce and grow. Want to grow absolutely incredible plants? The secret starts with providing them with the most stress free environment you can!
Don’t overwater! Keep the soil a little on the dry side. The number one way to kill a houseplant is overwatering. Don’t let the soils get too wet, especially at the bottom of bigger containers. Waterlogged soils create no-air or anaerobic conditions (vs. well-aerated or aerobic conditions). Why does this matter? You might notice that waterlogged soils smell bad (think swamps!) and that bad smell is actually produced by a set of anaerobic microbes that aren’t super great for your plants. Many beneficial microbes are aerobic and need air to thrive. Don’t let the anerobes (as they are called) take over and compromise your plant health with overly wet soils! Another reason to invest in good potting soil which holds moisture more evenly in a container. Soil moisture probes also exist for home gardeners to check soil moisture at depth.
Happy planting!
Resources mentioned above:
Potting Soil Mixes:
Coast of Maine: https://coastofmaine.com/
Vermont Compost: https://vermontcompost.com/
Organic Mechanics Soil Company: https://organicmechanicsoil.com/
Inoculants:
Advancing Eco Agriculture’s “BioCoat Gold” - https://www.advancingecoag.com/store/BioCoat-Gold%E2%84%A2-1-lb-p68500607
Fedco Organic Grower’s Supply “MycoApply Endo/Ecto mix” - https://www.fedcoseeds.com/ogs/mycoapply-endoecto-8176
Article by Fungi Perfecti with cool pictures of how mycorrhizal inoculants work: https://fungi.com/blogs/articles/mycorrhizal-management
“Healthy Soil Under a Microscope” 3-part Lecture Series with soil food web expert Monique Bosch with CT NOFA (Connecticut Chapter of Northeast Organic Farming Association): https://www.youtube.com/watch?v=BX6hdBRi1wI
*for a quick look at harvest comparisons, check the video around timestamp 24 minutes.
All-purpose organic fertilizers blends:
North Country Organics "Pro-Gro":https://norganics.com/index-12/index-11/fertilizers/progro/
Epsoma Garden-Tone: https://www.espoma.com/product/garden-tone/