My Low-Tech Process for Germinating and Growing Native Perennials
Catherine grew up on Long Island and got her love of nature and its creatures from her Dad, who, even when he was working 6 days a week would take the family out east on Sunday to walk in the woods, row boats and look for turtles. He always had turtles, frogs, newts, fish, and snakes as pets. Catherine has lived in East Northport for 25 years and is converting the yard into a native habitat in her spare time. Her family enjoys watching nature from their window and their yard. Catherine’s family especially love birds!
About 15 years ago, I started growing plants from seed, first out of economy but now out of love for the activity. There is something so hopeful about putting seeds in a pot, taking care of their every need and being rewarded with healthy plants. Especially when those plants are native and are helping support the local wildlife. Most of the perennials in my garden were grown from seed! You don’t need a lot of property to have an abundant native garden. My property is only 1/5 of an acre and I have over 30 varieties of native perennials and shrubs.
Germination Requirements
The first thing you need to do is learn about the germination of the plants you want to grow. The more you know about the plant you are trying to grow, the more success you will have. Some of my favorite plants are Wild Bergamot, Joe Pye Weed, Golden Alexander, Iron Weed, Smooth Blue Aster and Swamp Milkweed. I love to watch the pollinators on these plants. I also enjoy growing Yellow Coneflower and Purple Coneflower because they bring Goldfinches to my yard to eat the seeds.
The Prairie Moon Nursery website is a great place to start learning. (https://www.prairiemoon.com/) For every plant or seed they sell they have a code to explain the germination requirements. The germination code will cover pretreatment of seeds including cold stratification, light requirements and soil temperature. Simply search for the plant you are trying to grow, for example, Yellow Coneflower has a germination code of C(30). Thirty days cold stratification, I will explain that later. The steps I am describing will work for most, but not all, germination requirements.
The Wild Seed Project website also has excellent information on how to grow from seed. (https://wildseedproject.net/how-to-grow-natives-from-seed/) This article covers how to germinate, sowing seeds and waiting for germination. They assume you are putting your pots outside, but I have had better luck inside. You can try both.
GrowIt BuildIt is an excellent site and also has videos on YouTube with details on lots of native plants! (https://growitbuildit.com/). You can search on YouTube for the video you need. For example: GrowIt BuildIt wild bergamot. These videos will cover: what it is, why to grow it, how to grow it, how to save and germinate the seed and what wildlife it can bring to your yard.
My process came from these sources and also trial and error. This year I ended up with 65 pots of seedlings! A record for me! I am still working on getting them all planted in my yard, but that’s a great problem to have!
Cold Stratification
Most, but not all, native perennials require Cold Stratification. This prevents seeds from germinating at the wrong time of the year for survival. You are basically mimicking winter. If your selected seed doesn’t require cold stratification, you can skip this step! Cold stratifying timing differs, typically it is 30, 60 or 90 days, with most being 60 days. If you are not sure of the requirements for your seeds, it doesn’t hurt to cold stratify for 60 days. You can cold stratify seeds in your fridge. The seeds must be kept cold and moist, but not so wet that they mold. I use pots filled with damp Organic Seed Starting mix, add enough water to get the consistency of brownie mix. Plastic pots hold the moisture best. They can also be reused over and over again. I use 2 1/2 inch pots. Sprinkle seeds on top, generously, you can always divide them later. Sprinkle some clean sand (like you’d use in a sandbox) on top, lightly for tiny seeds, as if you were seasoning your food, and a more heavily to cover larger seeds. Label the pots so you don’t forget what it is. Place the pots in a sealed container. I like to use the plastic containers that salad greens come in. Be sure to remove the top label so later the pots can get sun. Make a note of the date so you know when to remove the pots from the fridge. Check every three days to make sure the soil is still damp. If not, water sparingly with a spray bottle. If you are growing several types of native perennials that have different cold stratification timing, you may want to start the 30 day pots a month later so all the pots are ready to move to the sun and heat at the same time. I start my 60 day plants around the third week in January. That gives them plenty of time to grow for planting outdoors. It’s also nice to be gardening in January!
Simulating Morning Sun and Afternoon Shade
Once the seeds have cold stratified, I use my low-tech method of simulating morning sun and afternoon shade using a south facing windowsill and a radiator. If you don’t have a south facing window and a generous sized radiator like me, you will probably need grow lights and heat mats. I haven’t used either of these techniques.
Place the container, still with the clear cover in place, on the windowsill at 8am. At around 1pm move it to the radiator for the rest of the day and night. The warmth and light will work for most native seeds. Check the containers every other day to make sure the pots are damp. Water as needed with a spray bottle.
Once the pots sprout, which could take days or weeks depending on the native plant you are growing, remove the cover. Just leave them in the sun from here on out. Once they have leaves, don’t top water. Fill a separate container with water and sit the pots in it for 10 minutes every other day. In the past when I directly watered the bottom of the containers, I had trouble with mold and the seedling would grow long roots out of the bottom of the pot.
When the sprouts have grown to an inch, you can move the pots to a regular plastic flat on the windowsill. I add a flat aluminum foil baking tray to the back of the flat to bounce the light back at the plants. Before I started doing this my seedlings would lean towards the window and get very leggy, looking for light.
Giving the Seedlings Room to Grow
When the seedlings get too crowded or are getting too large, split the bunches of seedlings into two, three or four clumps and move them to 3 inch separate pots. Keep the soil around the roots to limit root damage when pulling the chunks apart. Switch to organic potting mix at this time. Seed starting mix doesn’t have enough nutrients for optimum growth.
Hardening Off
Once your seedlings are beginning to look like miniature versions of the plants you are trying to grow, with true leaves and starting to reach a bit, it is time to think about moving your plants outside! I do this in batches, starting with the largest, healthiest seedlings. This will give the other seedlings time to catch up.
Indoor seedlings are pampered compared to outdoor plants and need to be hardened off in order to survive outside. This requires a week of moving them outside for increasing amount of time. Hardening off will help the plants adjust to sun, wind, rain and temperature changes. The process can be tedious but well worth the results! Start with one hour the first day and increase an hour each day, splitting the time between sun and shade at first. Don’t attempt to plant your seedlings outside until mid-May. One year I got over zealous and started to harden my plants out in April and it hailed! I lost a lot of seedlings! Beware of very windy or unseasonably cold days. Both can desiccate new seedlings. They can also get sunburned if you put them in direct sun for too long, too soon. The temperature should be at least 50 degrees and wind should be mild. Skip any day that the weather is not mild enough. Better to plant healthy seedlings a little later. Also, put them up on a table or bench to prevent rabbits and slugs from getting them.
Planting
After a week of gently exposing your plants to the elements they will be ready to grow outside. Be sure to plant the new plant in the right location for its needed growing conditions. Water well, dig a hole slightly bigger than the pot and mix in some compost. Put some water in the hole. Remove the plant gently from the pot and loosen the soil at the bottom to allow the roots to spread out. When placing the plant in the hole, make sure the soil level is the same as the pot soil level. Water frequently for the first few weeks.
The first year your seedlings may still be small. Next year they will grow considerably. The third year they will really take off! I know once you get results you will love growing from seed as much as I do! The added bonus of growing from seeds it that you will recognize the volunteer seedlings that pop up in your yard and you can move these new free plants to where you want!
Plants grown from seed also have the advantage of being more genetically diverse, a lot of the plants you can buy are grown from cuttings, which are clones of the parent plant. Each seed is genetically unique. I saw this in my garden when I grew native Hibiscus from the seeds I collected from my plant with pink flowers, some of the new plants had white, pale pink or red flowers!
Materials List
Native plant seeds
Organic Seed Starting Mix
Organic Potting Soil
Clean play sand
2 1/2 inch plastic pots
3 inch plastic pots
Spray bottle
Several Clear Plastic Containers with lids around 9 inches by 7 inches by 3 ½ inches, this will fit 6 2 1/2 inch pots.
Plant labels and sharpie marker
Helpful Websites
Finding Native Plant Seeds
Once you have a native plant garden you can collect your own seeds to propagate the plants that you love and want more of. I get most of my seeds from my own garden and only order seed packets when I want to add a new native plant to my garden.
I have had success with native seeds that I purchased from Prairie Moon Nursery and the Wild Seed Project but I have since learned that it is important, if possible, to choose native seeds that are locally sourced. They have adapted to the local conditions and evolved with the local pollinators. Check with local providers like KMS Native Plants or Dropseed Native Landscapes before ordering from a website. You can also swap seeds with friends or check if your local library has any native seeds in their seed library. At this time, it’s not easy to find locally sourced seed so If you can’t find local seeds it’s ok to order from Prairie Moon or the Wild Seed Project.