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Mimicking Nature's Deep Freeze

Alpine strawberries are too crazy delicious not to grow in abundance, from seed. The doing of it as an early-season indoor project is a bit of an adventure, but so worth the effort.

Dormant alpine strawberry seeds slumbering in the freezer drawer, between Seville orange juice and turmeric root.

And the best part? Anyone with a refrigerator freezer, some patience, a small flourescent light or growlight, less than two square feet of indoor shelf space, and a tiny spot of sun on a patio or balcony, can do this. Imagine picking and eating alpine strawberries still warm from the sun, or making your very own strawberry desserts all year long. You can and you should, it's not hard.

The proper term for using my kitchen refrigerator's freezer drawer to kick-start dormant alpine strawberry seeds and other native food and wildflower seeds, in preparation for planting indoors this month or next month (there is still time), is 'cold stratification'.

In permaculture language I am simply 'deferring to nature's logic' by mimicking the deep winter conditions that wild sown perennial seeds would experience outside when the weather turns cold.

Homegrown strawberry and vanilla bean preserves top coconut maple and vanilla chia seed pudding.

Not all seeds require kick-starting interventions, cold or otherwise, but those that require cold stratification to wake up from dormancy in the spring, were designed that way by nature. Seed dormancy is an evolutionary adaptation that prevents seeds from germinating until they are both fully mature and rested (internal conditions are optimal for growth), and the timing is right (environmental conditions are optimal).

After spending considerable time in the ground through the winter (or several), having their seed coats 'tempered' or weathered and stressed by the environment and the cold, spring conditions pull a trigger of sorts within the DNA of the seed embryo which allows for moisture to penetrate the seed coats and initiate the miracle of growth. How incredible is that? Nature is perfect.

Heirloom mignonette alpine strawberry flavour bomb

Seeds can be stored frozen for decades, centuries even, and remain completely viable. The instinct for survival and reproduction is built into seed DNA. Seeds are tiny miracles of evolution. Their hard seed coats protect delicate plant embryos within until conditions seem right for germination. Assuming seeds are planted at the recommended depth, and that moisture, light, soil aeration, and environmental conditions are suitable, they contain just enough energy to send down a single stabilizing root, and send the building blocks of sturdy stem and leaves shooting up through the soil and into the sunshine to photosynthesize and re-charge.

Those are the plant baby crib notes in very generalized form. There is much more detail to it all of course; all best presented by an expert in plant anatomy and reproductive biology (botany). Topics for another day.

For now, know that when we purchase seeds from a supplier, we can be confident that they are indeed well rested; that they have built up enough internal fortitude to germinate successfully, and enough strength to anchor themselves in their growing medium and send up their first single or set of leaves and begin the process of photosynthesis.

For the most part, garden store racks are stocked with packets of plug-and-play seeds that require little more than soil, water, sunlight, and a requisite minimum temperature to get growing in the spring. Alpine strawberry seeds however are among those that require a period of cold incubation, known as stratification, at a suitably low temperature, before ascending to a suitably warm temperature conducive to germination.

Seeds are tiny DNA powered miracles of evolution

There are other ways to break a seed's dormancy. Some seeds have very hard shells which require mechanical or chemical intervention to break, initiating growth. Pea seeds and some beans, for example, benefit from either soaking or 'nicking' to soften and/or break their shells just enough to let moisture in. This nicking process is known as 'scarification' - ie: wounding or scarring gently in a location that does not compromise successful germination.

There is plenty of very interesting information related to stratification and scarification including fascinating tidbits like gastrointestinal seedcoat softening that takes place in animal guts and poop, available online and in seed catalogues. If you are interested, you should definitely dip deeper, no pun intended.

As a permaculture designer, I value learning and understanding the natural science behind the processes, but I prefer to communicate and act on ideas simply; to untuit and think like nature, then mimic her systems.

Diminutive Alexandria alpine strawberry, so pretty

For me, at this point in the season, mimicry involves waiting for packets of organic heirloom Alexandria and Mignonette alpine strawberry seeds to emerge from their month-long hibernation in my kitchen freezer. I set them to slumber in a sealed, recycled freezer bag on January 20th, and I will remove them sometime on or just before February 20th. The seeds will emerge duly fooled by my trickery, and after leaving them to come to room temperature before opening, they will be ready to plant indoors in a seed tray, under grow lights and on top of a heat mat set to 75F/24C, for optimal germination.

My seed starting rack is in my home office, so I will be able to monitor their progress, or lack thereof, for as little as one week and for as many as six, before they germinate. Assuming they do, I should be able to grow them indoors to sufficient size before hardening them off for planting outdoors, in time to expect fruit set this season. If I miss the window this season, which could happen if the seeds take extraordinarily long to germinate, I will have something to look forward to next year.

Worth the hassle? Indeed. Alpine strawberries are flavour bombs of deliciousness. I can still taste every alpine strawberry that my family ever picked along favourite shoreline spots in British Columbia, and also in Sweden, where my brother lived for many years. Extreme weather and cooler temperatures result in comparatively small sized berries packed full of concentrated goodness. Wild northern blueberries deliver this same level of deliciousness -- a reward perhaps for those of us who endure longish winters.

My intention for the homegrown alpine strawberries, is to utilize considerable barren space below a clipped boxwood hedge. The hedge is classically beautiful, but entirely unproductive. This particular hedge, plus several others, were part of the 72 year-old landscape when we moved into this house 20 years ago. Maintaining it for the sole purpose of aesthetics, has caused me considerable guilt. Removing the hedge is not an option, as it is a well-established habitat for many birds and small creatures, and it acts as a windbreak for vulnerable and valuable plantings.

Resident chickadees, towhees, sparrows, warblers, flickers and hummingbirds love fresh strawberries

If however, underplanted with 50 or so alpine strawberry plants, the hedge can become a productive and righteous member of our urban permaculture garden, feeding my family as well as birds and pollinators. A length of drip irrigation line runs the length of the hedge already, at ground level, which should be sufficient to keep the strawberry plant roots well watered, without wetting the fruit and exposing it to mildew.

If you grow strawberries at all, either cold stratified alpine berries from seed, or everbearing strawberries from nursery stock plants, I encourage you to preserve some for those winter months of slumber, when we need a sweet reminder of summer.

Vanilla beans, packed one per jar, add intense flavour to strawberry conserves, especially to syrup (top row)

I supplement the berries that I grow in pots and in our garden, with wild berries purchased from a forager and/or organic berries purchased from a local market gardener. I hot-water-bath preserve them as a low-sugar (half) conserve with whole vanilla bean but nothing else. Without full sugar or added pectin (strawberries are naturally low in pectin), the conserve is a-typically syrupy, which I think is gorgeous. I call the soupy conserve 'jammish' because it is exactly that, not jam and not syrup, rather an in between sort of preparation that lends itself to all sorts of culinary applications - both sweet and savoury.

Last summer, the strawberries were particularly ripe and juice, and after cooking down only slightly with the warmed sugar and split vanilla beans, I was able to preserve as many jars of strawberry syrup as I did the jammish conserve. We have been enjoying the syrup over pancakes and waffles, and in summery cocktails. The jammish is spectacular in chia seed pudding made with coconut milk and maple syrup (shown), drizzled over vanilla ice cream, or heaped onto warm slices of fried buttermilk pound cake. To learn more about preserving strawberries, visit my Instagram page.

Alpine strawberry seeds are available from several seed breeders and suppliers in the United States and Canada. I encourage you to search for small, family-run seed farms, committed to the preservation of resilient native and heirloom seeds. If you cannot find alpine strawberry seeds online, or simply run out of time, plant whatever strawberry seeds or plants you can find, whenever and wherever you can, and I promise that your efforts will be delicious.

The objective after all, is to just get growing!

To learn about urban permaculture and permaculture principles, such as those relating to traditional environmental knowledge, and adherence to nature's logic, watch Modern Farmer Magazine's Urban Permaculture video series in which publisher Frank Giustra and I introduce the basics.

If you haven't subscribed to MF's Million Gardens Movement newsletter, please do.

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