Growing Perennial Flowers from Seed

It is surprisingly easy and cheap to grow your own garden from seed, though there are a few things you need to know.

Most native plants need to go through a period of cold weather in order to be able to germinate in spring.
Therefore collected seeds need to be stratified.
There are different ways to do so:
Let winter do it naturally through outdoor cold moist stratification
or mimic conditions in your fridge.


Find Out Which Method Works For You


Seeds are sown outdoors between November and February and stratify naturally

+ No need for plastic bags

+ Takes no space in the fridge

+ After sowing no need to check on seeds until March

+ Very easy process

- Unwanted seeds are still plentiful in the fall and can fly into pots

- Small mesh is required to keep mice and birds from eating the seeds

- When plants sprout in spring it has been too long to remember things. Therefore it is paramount that every pot has a label written with a very durable pen

- Location of pots most likely will have to be changed


Seeds are sown between March and May and stratification needs to be mimicked in the fridge

- Seeds need to be stratified in plastic bags in the fridge
- Different seeds need a different length of time to finish stratification, some start germinating even in the fridge after dormancy is broken
- The process requires some planning since different species require different periods of stratification
- Protection against squirrels is needed
+ Hardly any seeds are still flying around so you have almost full control over what will grow in the sown pots
+ This makes it a very successful process 
+ It feels very good to get gardening when warmer days become pleasant
+ Plants germinate very soon after sowing so it feels like a continuous process that you are part of


Seeds are sown between the 21st of December and February and stratify throughout winter

- Plastic containers with the matching lid need to be collected

- Time-consuming to put set up together

+ After sowing until March only sporadic checks on seeds are necessary 

- Absolutely no unwanted seeds will get into the pots; full control over what you grow

- No extra protection against mice, squirrels, and birds eating the seeds is needed

- Might promote pathogens on usually hardy plants through the consistent presence of moisture

+ Takes no space in the fridge

+ After sowing until March only sporadic checks on seeds are necessary 

+ Plants germinate earlier in spring and develop quicker

+ Continuously moist environment through condensation and recycling of the water benefits moisture-loving plants that are otherwise finicky to get to the seedling stage. 

+ Great for very tiny seeds that need light to germinate since they can be safely surface sown and stratify naturally. No need to mix them into soil to stratify.




seeds will stratify naturally going through the winter outdoors


November until beginning of February

Fill containers with well moistened potting soil.

Sow the seeds on top and

gently press them to have contact with the soil. Sprinkle with a bit of soil.

Label each pot with the name and the source of the plant if you know it to be able to support genetic diversity in a planting.

Put in a location

that will receive rain and snow, that is far from stems with seed heads,

and is in the shade.


After Sowing

To give extra protection cover with a layer of leaves.

Protect from squirrels, birds, and mice by covering the pots with a fine mesh and tucking it under the pots.


March until April

When the days get warmer take off the leaves and move the pots into a sunny location.

The seeds will germinate at very different rates depending on their species.

Seedlings are ready to be planted in the soil in summer or fall. 







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This explains the basics of indoor stratification in the fridge and will work for most of the seeds


From Harvest until Cold Moist Stratification


Keep the seeds in paper envelopes that are labeled with the plant name, location, and date of harvest until you need to start the stratification process. This is around mid-February for most plants.

For the exact length of the required stratification time and method check out the website of Prairie Moon Nursery

To figure out when to start the stratification process, count back the required days of cold moist stratification from the day you want to plant.

From February until March


To stratify the seeds transfer them onto a moist paper towel.

Fold the paper towel in half or quarters and put it into a Ziploc bag.

Close the bag tightly.

Label with name, location, and start date of stratification. For ease of use, you can either add the needed CMS days or the date when seeds are ready to be planted.

Keep the bag in the fridge until you sow the seeds outside.



seeds must have been stratified either in the fridge or on the plant outdoors


From March until May

Fill containers with well moistened potting soil.

Sow the stratified seeds on top and

gently press them to have contact with the soil and add some soil on top.

Water well.

Label each pot with the name and the source of the plant if you know it to be able to support genetic diversity in a planting.

Put in a sunny location

and make sure the soil never dries out.


After Planting

Protect from squirrels, birds, and mice by covering the pots with a fine mesh and tucking it under the pots.

The seeds will germinate at very different rates depending on their species. It is very important to never let the seedlings dry out.

(This box of butterfly weed seedlings already fed 5 monarch caterpillars as small seedlings.)

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April to August

The seeds will germinate at very different rates depending on their species.

In June most seedlings have to be up potted to be able to grow bigger roots.

Mature seedlings are ready to be planted in the soil in summer or fall. 



seeds will naturally stratify outdoors

Winter sowing is a fun method that uses mini green houses to speed up the growing process of the plants. The plants will be very abundant, healthy and ready to be transplanted  in summer.

You can find a very detailed video by Dolly Foster, a Master Gardener, on Wintersowing.


From December 21st to the Beginning of February

Sow seeds onto moist soil in a deep container to support vigorous root growth.

Best to add some snow on top.

Label inside and outside with a very durable garden pen.

Water that soil is well moistened but not wet.

Tape the lid onto the matching bottom.


During Winter

Keep containers in a shaded spot or one that doesn't receive midday sun that the sun doesn't heat the little greenhouse up to extreme temperatures.

Keep an eye that it doesn't dry out which is very unlikely.

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Starting in March

Put containers into a partly sunny place. On warmer days open the lid and only close it at night.

Once the last danger of frost has passed and day and nighttime temperatures get warmer take off the lids altogether.

Seedlings will soon have to be up potted and transplanted into the gardens.



Containers & Soil

Any container that is at least 5 cm /2 inches deep can be used. 
If the container doesn't have drainage holes, cut holes into the bottom.
Any potting soil is sufficient, there is no need to buy seed starting mix, but finer chopped potting soil works better. 
Most soil comes rather dry. To safe time you can pour quite some water into the opened bag and let the soil absorb it for some hours. Soil needs to be evenly moist before sowing.
Fill containers and tap them to settle the soil until the containers are almost full.
Leave about half a centimetre of room at the top.


Sowing Your Seeds

Put seeds on the palm of one hand, pick the seeds you will sow, and sprinkle them as evenly as possible onto the soil.

Very gently press them into the soil and add a dusting of soil or coarse sand on top. As a rule of thumb, seeds should get covered with soil about their own thickness. Smaller seeds often need light to germinate and therefore should just be sown on the surface.

Water gently to settle the seeds.

It is helpful to mark every container with the name of the plant and the origin of it. This enables to grow individuals of the same species from different sources close together that through cross pollination a more diverse and resilient gene pool can be created.

Cut-up yogurt containers work very well to create your own tags.

For detailed instructions on how to sow check out Heather McCargo's short video.



Depending on your area, you might have to protect the pots so that squirrels can't dig up the soil and destroy the seedlings.

The easiest is to use a sturdy plastic netting.

Chickenwire is a method that works very well - but working with chickenwire is quite unpleasant unless you build a cage that you can use for years.

It is surprising how effectively simple plastic bags prevent squirrels from digging. Be aware that this method creates a greenhouse that provides a warm and moist environment that is ideal for germination much earlier than without this protection. If you just cover the seeds directly with a plastic bag like a blanket at night to prevent squirrels from digging you need to take it off during the day. On the other hand if you build a structure that the seedlings can grow till the end of May, you can leave the clear bags on it because you created a perfect simple green house.  As the evaporating water condenses and drips back into the soil watering needs are reduced to a minimum.

See-through containers with a matching bottom from the kitchen recycling can also be made into squirrel-prove greenhouses. 

From my experience most native plants don't need that head start given through a greenhouse. It is a great method though for annual herbs that support butterflies like fennel and dill.

In May it is best to take the plastic off since the moist environment favours mold growth.


Caring for Your Seedlings

Seeds will germinate at their own pace depending on daytime temperature, nighttime temperature, moisture, and light conditions.

Once the seeds have sprouted and are small seedlings they must never dry out. From now on check daily if the soil needs watering.

Once the seedlings have their second set of true leaves (cotyledons are the very first leaves that often don't look like the plant's leaves) it is time to up-pot the seedlings. Divide them into pieces of about a square inch and put them - just as they are as one piece - in the middle of a bigger pot. This way the roots don't get damaged and they have space to move outwards.

Since potting soil has fertilizer added and most native plants, particularly prairie plants, thrive on poor soil there is no need to add fertilizer at any time.


Ready to Be Planted

Most Plants Will Be Ready To Be Planted By Summer

It is important to match the plant to the right conditions of a location so that the plant can thrive. 

Even drought tolerant plants need frequent watering until their root system is well established.


Heather McCargo, founder of the Wild Seed Project is an excellent source to learn more about growing native plants from seed. 

She has decades of experience with a wide variety of native plants, methods and soils. The featured talk will carry you off into the wonderful world of growing your own native plants from seed and contributing to genetically diverse seedlings.


Toronto Based Resources

Pete Ewins shares his own experience of collecting seeds and growing native plants from his Toronto back yard.

Local seed exchanges are organized by Seeds of Diversity, NANPS, and the Cliffcrest Butterflyway.