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  • Rick and Doris Wukasch

Propagating Native Plants on a Paved Paradise

Updated: Nov 16, 2021

by Rick and Doris Wukasch

How we got started

Our interest in native plants has grown throughout our lives through camping, hiking, and university education in botany, environmental and agricultural biology. We ventured into native gardens a decade ago in the shade of our backyard with alternate-leafed dogwood, witch hazel, native ferns and perennials. Our son, Simon, developed a native plant oasis in south Etobicoke, demonstrating how an interesting, diverse and attractive habitat could be created in the urban landscape. Then as a neighbourhood friend installing a Blooming Boulevards (BB) garden introduced us to Jeanne McRight and Wayne Cardinalli, and we too became garden stewards.

In 2020, the Creation Care team at our church community, The Meeting House, had completed a very successful first year during the pandemic of growing a vegetable garden for food banks and a shelter in Oakville/Mississauga. We also made plans to restore a swale on the property which was infested by invasive non-native plant species, and arranged to grow native plants for BB as well as for recolonization of our swale with native vegetation. What a great use during the off-season for these raised beds – a stratification site for germinating native plant seed!

Our seed sowing party

BB supplied seed, cups, soil, labels, and know-how, and we supplied the volunteers for a ‘seed sowing’ party on a late-November day. Thirteen varieties of seed were sown and lightly tucked into ProMix soil in labelled cups for a long winter’s sleep, then moved into the outdoor dormitory until the raised beds were filled up with over 900 cups. A mesh cover was secured onto the top of each bed to prevent rabbits and mice from disturbing their sleep.

What a great use during the off-season for these raised beds – a stratification site for germinating native plant seed!
Winter rigors? No problem!

Though the soil became compressed under the weight of snow and heavy spring rains, by April germination had begun. We selectively took cups with tiny plantlets indoors when their two cotyledon leaves were visible and began transplanting them into other cups. We were amazed at how extensive their root systems had already grown and tried to transplant them before seed roots ramified and became too entangled to easily separate!

  • Species whose roots were most vigorous were separated for transplanting first. Each cup was “operated upon”, the cup-shaped soil column carefully moved out of that cup.

  • When seedlings were clumped, we gently teased them apart in water in a plastic dish pan, spreading them out on a rock “island” with roots submerged in water.

  • We then created a depression with finger or tool in the same type of soil mix in a new cup, and gently lowered and tamped one plantlet into each depression, topping up the soil.

  • Each cup was watered immediately to promote an uninterrupted connection with soil, water, and roots.

Nearly all survived really well, with very few losses! With TLC treatment, young native plant seedlings (especially in the cotyledon-leaf stage) are very adaptable and hardy to withstand transplant, movement, and variable conditions outdoors.

Our hoop houses worked well

Established briefly under grow-lights indoors, cups were moved outdoors as soon as possible and grown in homemade hoop house cold frames in our south facing driveway until ready for gardens. Each of these economical structures were easily made from readily available materials, costing about $60 each. Heavy duty plastic sheeting was rolled onto an 8 foot long 1”x2” plank and screwed into the base of the cold frame. On the other side of the cold frame, the plastic was stapled onto a free moving 1”x2” plank and used to roll up the plastic during hot daytime temperatures, and unroll to cover the hoop house during cold, windy, or freezing conditions when seedlings were vulnerable.

See end of article for Rick's downloadable directions on how to build these hoop house/cold frames!

Yes, we watched the weather carefully for night frosts and sub-zero events. Compared to our vegetable transplants, these natives are hardy little things, well suited for fluctuating spring conditions. In early spring during warmer days, the plastic sheeting at the ends of these cold frames was rolled up and clipped (using large butterfly clips) to the end hoop for air circulation; at night, unrolled to keep the warm in. When near freezing, we occasionally pulled a tarp over all the hoop houses as an extra layer of protection. In the warmer months of May and June, we took the plastic covering off completely and rimmed the perimeter with chicken wire mesh to keep the bunnies out. But the native plants are extremely resilient.

With TLC treatment, young native plant seedlings (especially in the cotyledon-leaf stage) are very adaptable and hardy to withstand transplant, movement, and variable conditions outdoors.

We tended the plants by watering often, and weekly with a dilute 20:20:20 solution. Because they sat right on our south-facing, black asphalt driveway, and the roots were almost pot bound, some days needed 2 waterings.

Germination depends on many factors such as seed viability, proximity to the soil surface if light is a germination stimulant, or soil temperature as in some late season grasses. The same species may germinate over a long time period, or if soil from the originally planted cup is mixed on top of fresh soil and seed exposed to light, or just naturally later in spring during hot weather. Our grasses in particular were irregular or poor in germination. We had to wait patiently for planted seeds to come to full term, finding that some native grasses germinated late and sparsely. We advise planting more seed than you think you need, especially with grasses more than other species. Water, wait, and watch closely for signs of life.


Just before the June BB Native plant sale, roots had nearly filled the pots and were growing out of the bottom of their cups, and depending on the species, leaves were large and plentiful.

Although we loved our ‘little babies’, they had grown up. As garden “parents”, we were glad to see them find new homes in the earth of someone’s beloved native plant garden! We put the cups into plastic garden centre trays holding 18 in each, loaded up a trailer covered with a well attached tarp, and delivered the babies to Jeanne and Wayne’s nursery for safe keeping. Then our hoop houses were disassembled and stored away for summer dormancy in our garage rafters until repeating the process next spring. Hopefully with a bit more experience in native plant obstetrics!

Plants we grew

Plants we seeded in Nov.2020, and delivered in mid-June, 2021 were:

White yarrow, evening primrose, butterfly milkweed, black-eyed susan, dotted mint, pearly everlasting, heath aster, anise hyssop, grey-headed coneflower, little bluestem, prairie dropseed, panic grass, Indian grass (Sorghastrum Nutans).

Which ones might be guests in your driveway or patio this spring? Let’s propagate plants on a paved paradise!

How To Build A Simple Hoop House Cold Frame For Growing Plants Outdoors
Download PDF • 33.52MB


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