Do you feel you don’t have the nerve, time or skill to germinate perennial seeds? Don’t worry. You’re not alone. Step right this way. I’m going to show you how easy and how much fun sowing perennial seeds can be.
The love of gardening is a seed once sown that never dies
-Gertrude Jekyll
I worked for Jelitto Perennial Seeds for 22 years and learned a few tricks. I am a little biased. The good people at Jelitto, upon my retirement in 2018, gave me the passcode to their seed bank and free seeds for life.
Sandwich baggies with perennial seeds and medium-grade perlite, undergoing a six-to-eight week cool-moist treatment, prior to sowing in sand beds.
I love to sow seeds, not only for perennials, but also for trees, shrubs, bulbs, annuals, and vegetables. Yes, there are always a few pitfalls. Seeds can be overwatered or underwatered, and seedlings die, but the act of seed sowing is an inexpensive way to grow your own plants. It’s worth a shot.
Let’s cut a few corners
You won’t need a greenhouse, cold frame, grow lights, or water jugs. You need only seeds, plastic sandwich baggies, medium grade perlite or fine sand, and a little room in your refrigerator or a cool garage.
Some perennial seeds germinate evenly in a greenhouse, within weeks—like hair on cat’s back— with temperatures hovering around 68 F (20 C). Here’s one idea: You could wait and choose to sow these seeds directly in an 8″ sand bed a few weeks before last frost and let nature do the rest. Other perennial species may geminate unevenly over 4-6 weeks and benefit from a moist-cold stratification for 6-8 weeks. The sand bed is good for these seeds as well.
Other trickier species need to be sown fresh upon ripening. Still others may have to overcome the female dominatrix, triploid endosperm, to germinate. No need to go deep into the weeds, or bore you, with seed physiology.
Germination tips for every Jelitto seed item, are featured on the last few pages of the Jelitto catalog. Download catalog here:
There’s an alternative and easy way to sow most perennial seeds
At this time of year, there is a simple germination technique. It will work whether seeds are bought from seed companies; are a member’s perk from North American Rock Garden Society’s Seed Exchange; or are harvested seeds free-for-the picking from your garden.
Place your perennial seeds this winter in sandwich baggies mixed with moistened medium-grade perlite or fine sand.
Dianthus isensis ‘Dancing Geisha’ is a mix with fringed blooms in white, pink, purple and red shades. Mary Vaananen photo.
Put the seed baggies in a box, seal it up, and place in a refrigerator or a cool garage for 6-8 weeks. Check the bags every week or so to be sure the mix is still moist. Spray water, but don’t drench. There may be a few surprise seedlings. You can prick these out, pot them up, and place on a sunny windowsill.
There are often advantages to having temperatures that fluctuate up and down, so the garage is my preference. Even a few degrees of frost won’t hurt anything.
Allow 6-8 weeks of this cold-moist stratification that mimics variable outdoor winter conditions. Then, afterwards, go ahead and spread the seed mix in an 8″ sand bed. (Imagine a child’s small sand box 3’ x 3’.) Barely cover with sand, and then water.
Germination will begin as spring unfolds
I try to thin out sand-bed seedlings in May, and plant them in the garden, but I don’t always get to this. The perennial seeds root into the sand bed, fight for control, and the survivors will be planted the next spring. The 8” sand beds inhibit considerable, but not all, weed seed germination. Summer watering requires a little vigilance, but it’s fun to check regularly on your seedling nursery. The sand beds do dry out, but the perennial seedlings will penetrate deep into the beds where moisture is pulled from the ground.
Heliopsis ‘Burning Hearts’ with a milkweed bug. Mary Vaananen photo.
Perennial seed recommendations
I asked Mary Vaananen, Jelitto’s North American Manager and popular Garden Rant guest contributor, to recommend a few Jelitto Perennial Seed selections that can be sown with moist medium-grade perlite, or fine sand, in sandwich baggies this winter. Mary confessed. She hadn’t started seeds in baggies. She prefers, like many gardeners, to grow easy-to-germinate perennials on a sunny windowsill where she can keep a close eye on her babies, but the baggies would work with her pick hits, also.)
Mary Vaananen in a Jelitto seed packet costume made by Jaime Manlove of North Creek Nurseries.
“Cymbopogon flexuosus (east Indian lemongrass) is one of my go-to herbs every year. I usually sow them in March indoors and then transition them outside gradually to a protected place, so they get enough light to grow straight before transplanting. Very easy and quick to germinate.
“Heliopsis Burning Hearts is one of the most cheerful flowers in my garden. Uncomplicated and easy to grow from seed, it even seems to flower well in the dappled shade I garden in. In more sun, the leaves are a burgundy color which adds to its ‘look at me’ factor. If you fall in love with ‘Burning Hearts,’ you will probably have to try ‘Bleeding Hearts’ too. Deep red-orange flowers that fade to dusty orange bronze.
“Dianthus ‘Dancing Geisha’ has unusual flowers with drooping shredded petals…really cool! Another easy to germ perennial that flowers the first year from seed. ‘Dancing Geisha’ is a color mix of pinks and purples, red and white.”
Mary adds a last piece of advice
“Transitioning new seedlings from indoors to outside must be done over a bit of time, being conscious of the light and temps. You don’t want to shock tender seedlings with too much sun or cold (or heat). Definitely keep them out of direct sun when first giving them outside exposure. A shaded area for the first week is good. Be mindful of temperature. If you feel comfortable going outside in the spring (from indoor temps), the seedlings will probably too. Low to mid 60s should be safe.”
Different ways to skin the cat.
You’ll never know the joy of little seedlings unless you try.
Let me know what works for you.
It’s how I made our garden, though not in baggies.
Hard to believe that I once wondered how on earth I could fill two acres with desirable plants and now I don’t sow, because I can’t find places to squeeze new plants in. You must be right, Allen.
Filling up two acres is impressive, but there must be room for a few new seedling perennials somewhere…
FG
Growing from seed is a great project. I only do natives, now, but I started with the Rock Garden Society’s annual seed exchange…lots of interesting choices! Sharing extra plants is good.
Lynda, I’m glad you also endorsed the Rock Garden’s annual seed exchange. My seed packets should arrive anyday. I am so excited. I sow lots of wild collected natives, also. Seed love!
I tried the baggie trick a few years ago when I needed a lot of perennials to fill a new bed. It worked like a charm and I’ve been doing it ever since.
Sheena, I’m glad you had luck with the baggies. Thanks for commenting.
So much to love about this post. Thank you Allen for demystifying the process for so many. I’m going to try your baggie technique tomorrow with my Jelitto order (and my NARGS seeds too!) – MW
Thank you, Marianne. Good luck with the baggies. Keep me posted.
I’ve been cold stratifying and priming seed for a lot of years in baggies, but since I prefer to then sow them individually in plug trays for efficient transplanting, I don’t mix them with anything else that would complicate the process. Just seed and water. Tip the desired mount of seed into the baggie, add a teaspoon or so of water, massage the seed gently to overcome the surface tension and wet the seed, and finally dump out any excess water (without dumping out the seed). When it’s time to sow them, dump/wipe/cajole the seeds onto a paper towel and blot with another, rending them dry enough to then be sown with a vibrating seeder. A different approach for a different purpose. Oh, and lets not forget to get out a Sharpie and mark the baggie with all of the pertinent information.
Joe, thanks for filling in the blanks! You might try sowing your temperate seeds in a small sand bed. I’ve enjoyed this as a stand alone, and in conjunction with the baggies.
I use 4″ pots to winter-sow native perennials, but have been thinking about trying the perlite/sand idea. And the sand bed is such an interesting idea! Thanks for the useful information.
Sharon, the 4″ pots are a very fine way to winter sow perennials, allowing for a sufficient cold period. I’m glad you’re willing to give the baggies a go and add to your repertoire.
Allen, thank you for this wonderful stimulating article. It takes me back to the days of being a student again with you at Kew Gardens when never a day passed without some exciting idea or observation being shared in our group and making life more interesting. I forget to sow seeds here in the Australian Tropics but am always taking little plants that my daughter, who orders and sows her seeds every year, produces in her rambling unstructured garden (only a short distance away from us). I don’t know many people in our part of the world who use seeds like she does. We rarely do perennials in the tropics. Once I get my little treasures home (and remember to actually plant them) I am continually amazed by the emergence of combinations of plants, that are unplanned but perfect, popping up in unexpected places and putting my carefully contrived groupings to shame. I find myself telling my customers to pop a few salvias into the carefully planned Australian native design that I created for them, and I get a few raised eyebrows (they’re weeds aren’t they?), but oh that mix of baby Bloomfield pendas (Xanthostemon verticillatus) with their fluffy little lemony green flowers and the unkempt mauve and red salvia flowers peeking through the pool fence looks so delicious. I’m going out to order more seeds today!! I needed a friendly prod to try something a little different this year. Maybe I should also take the time to photograph some of these little wonders too. A very good start my day. Thank you.
Suzan, you made my day. I am forever grateful for my one year at Kew. Everyday was jaw dropping. I remember sowing seeds one day with Sue Tasker. I was following her lead. She was patient and knew what she was doing. I was fumbling around and not nearly so careful. I am a bit more patient now… You painted a beautiful picture of your daughter’s love of gardening and her interest in seed sowing. Molly, my daughter with Ali, is also a keen gardener. She’s teaching me about foraging and herbal properties of wild things. I feel so honored to be in her garden and in the woods. I like the image of your Xanthostemon with “unkempt mauve and red salvia flowers” It’s good to hear from you.
The wonder of seeds never grows old! Last year I found some seed I’d gathered from Rumex flexuosa years earlier. My parent plant had died but I have a thing for brown plants, so I had to try. I’ve now got 3 tiny seedlings, all beautifully the dull color of mud, waiting to find their way back to the garden. Specialty pansy seed recently spent a month or so in my refrigerator before sowing. Just the other day I caught sight of teeny tiny green sprouts emerging. My plan for these humble-but-gorgeous pansies is to grow them as long-stemmed cut flowers — seems like every year I have a “new” project and the best ones typically involve seeds.
Bravo for rescuing and championing the bitter sorrel. I’ve got a thing for a couple of Rumex species, also, but try to be careful they don’t go too wild on me. Long-stemmed pansies as cut flowers. Sounds dreamy.
Allen, this was fun and informative, but the best part was being able to hear the cadence of your voice in the words. I’ll have to go and poke around in my seed box and see what will grow!
Thanks, Jenny. Happy seed sowing.