- by Grey County Master Gardeners

It’s always at this time of the year, when the winter solstice has passed and we are looking at ten more weeks of bleak weather that I begin to get fidgety for starting seeds.

Having perused my seed catalogues and ordered far too many packets for my summer vegetable garden, which I won’t start until March or April, I recall that I had committed to trying to grow native plants this year.

Oh dear. Native plants, as far as I have read require a number of months of cold weather, and the sage advice given is to plant them in the fall and let them go through a freezing cycle provided by the winter. Did I miss the window yet again? Well, maybe not.

There are a few techniques that can help circumvent this fall planting process, and speed up or imitate the cold conditions required by many native plants to facilitate germination. And it begins in your kitchen!

The horticultural term for this process is stratification, which is basically a process of treating seeds in a way that simulates natural conditions – the overwintering freezing or freeze/thaw cycle. This is necessary to break dormancy – or stimulate the seed to germinate.

What you plan to sow will determine when you need to start this process and for how long the seeds should be exposed to this period of cold. For this I highly recommend using a reputable supplier of wildflower seeds. The information for optimal germination will be printed on the packet. I bought my two packets from www.wildflowerfarm.com – one packet of Geum triflorum ‘Prairie Smoke’ and one of Allium cernuum ‘Nodding Wild Onion’. They each require a different process.

For Prairie Smoke, the process has a few steps. But once you’ve seen the Prairie Smoke in flower, you’ll know why this is worth the effort. I won’t start my stratification process for these flowers until the beginning of March.

The steps are as follows - Mix the seed with a moist seed starting mix and put it into a plastic bag labelled with species and date. Then store the packet in the fridge for 24 hours. Then take this out after 24 hours and transfer to the freezer for 24 hours. Repeat at 24 hour cycles between the fridge and freezer for a total 7 days.

After that plant into 3” pots keeping moist and very warm – I use a heat mat. Once the seedlings are about 2” high and night time temperatures are above 10’c (about the end of May) you can plant into the garden.

Nodding Wild Onion requires cold moist stratification. This is a longer stratification period but a less cumbersome process. I did this at the end of January, so there is still plenty of time for you to do as well. I scarified (scratched) the seeds gently between two emery boards, then placed the seeds into a small plastic snack bag with some moist but not wet sterile seed starting mix. I marked the bag with the species and date and put it into the back of my fridge. It will sit in here for 6-8 weeks. After this time, I will transfer the mix into 3” pots and keep the moisture warm and moist on a heat mat or above a radiator until the seeds have germinated and are about 2’ tall. This second part of the process is called warm stratification.

I will plant these outside in the garden at the same time as the Prairie Smoke.

For those who have the seed starting bug, this is a third method for starting seeds early to get ahead of the annual rush. For this method we start them using clear or translucent plastic jugs. You can start this now. Ideal seeds are Centurea ‘Batchelor Buttons’, Lavendula ‘Lavender’, Calendula officinalis, ‘Calendula’. Though not native species these are beautiful annual flowers.

To prepare, punch holes in the bottom of the jug. Water or juice jugs work well. Remove the cap. Cut the jug horizontally into two through the middle of the jug, leaving about two inches uncut to form your hinge which you can flip back to put the soil in. Fill the bottom of the container (2-3”) with a lightweight bagged potting mix, water and then leave to drain so it is moist but not wet.

Sprinkle the seeds on the surface and cover to the depth indicated on your packet with the same moistened soil.

Close the container and seal using duct tape. Label and put outside without the cap to ensure exposure to the elements but if you can, set it out of wind.

The conditions in the containers will replicate a cold frame and eventually, the seeds will germinate – usually in early spring. Water the pots if they are dry. And keep the lids on until the nights are warmer but don’t let them dry out at this stage. When you are ready, transplant them into larger pots for growing on or put them outdoors when temperatures are about 10’c nighttime temperatures. Having germinated in these conditions your plants are more hardy then usual sowing.

There is a unique satisfaction in seeing flowers bloom that you have grown from seed.

Happy sowing!

Go to greycountymastergardeners.com to register for a FREE seminar on Gardening for Wildlife – to be presented on Saturday, February 26, 2022.