Gardening Tips: Stratifying & Scarifying

Editor’s Note: I noticed the seeds on display at the hardware store this past weekend and realized it was time to bring back the gardener, so here’s a column that first appeared on 22 February 2017.


What to do this week

This week I want to talk about stratifying and scarifying. These are two tricks for germinating hard to start seeds such as the seeds of many perennial flowers. I mostly concentrate on food gardening but perennial flowers can be so nice, and lots of them can be useful, like Echinacea. If you start perennial flowers from seed, they are a fraction of the cost of buying them plant by plant at the garden store. Celery, celeriac, parsley and certain herb seeds can also be hard to germinate. Some herbs are easy, like basil, but others are stubborn.

By U.S. Department of Agriculture (Seedling) [CC BY 2.0 (], via Wikimedia Commons

Seed germinating. (Photo by U.S. Department of Agriculture, CC BY 2.0, via Wikimedia Commons)

Perennials can be difficult to germinate because they play the long game. Their strategy is to germinate once and live for a long time. Annuals, like most vegetables, have a different strategy. They like to germinate, live one year, and produce a lot of seeds. They are all about germinating quickly, but perennials with their long game are not in such a hurry. There are some tricks to help you with that and one is stratification.

This is one of the few cases where I do not use soil blocks. You need a small tray — mushroom containers from the grocery store are perfect. Fill your tray with your soil mix, plant some seeds, water them, put the tray in a plastic bag, and put it in the fridge for a week. When you bring it out into the warmth for a week or two, the seeds will think the winter is over, so they will germinate. If they don’t, put them back in the fridge for another week and try again. Usually once is enough. The plastic bag is useful to help keep your fridge tidy, but it is also important because some fridges work by dehumidifying the contents, and you don’t want that.

So this is stratifying. It is very handy. I do it with all my parsley and celery.

The second trick is scarification. This trick is for very hard coated seeds like sweet peas. Sage also has a very hard shell. These seed coats are so hard and so impervious that it is difficult to get them to absorb water to start the process of germination. You don’t want to break them open, of course, but you have to help them with that hard seed coat. Take the seeds and put them into a jar with a piece of rough sandpaper. Shake the bottle for a bit, maybe 30 seconds or a minute. This gives you tiny scratches on the seed coat that will help let the water in and get the germination started.

Now is the time you want to be starting perennial flowers. These plants generally won’t flower the first year, and will just give you lots of leaves. It would be nice to not have to wait until the second year for flowers. If you start these seeds now, and use these tricks for germination, you might see flowers in year one.

During the upcoming two weeks I will cover winter care of trees and shrubs, including getting ready for pruning, followed by edible landscapes and getting ready for a trip to the nursery.

snowflake border




Market gardener, farmer, workshop leader, seed-saver, political candidate and mother, Michelle Smith has spent over 30 years coping with the challenges of our bioregion and in the process has built a store of practical and technical knowledge. The Inverness resident has served on the board of Seeds of Diversity Canada and represented Alternative Producers with the Federation of Agriculture but can do nothing about her hair. She is pictured with a head of Club Wheat, a seed that shares her approach to hairdressing.



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