Dear Avant Gardener

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Save Money with Winter Sowing

Heather Evans

Forget mow and blow; propagating native plants is the new, new thing.

My New England germination nursery in February last year

Dear Avant Gardener, Can we save money by growing native plants from seed? Installing one plug per square foot as you recommend quickly runs into thousands of dollars. We would appreciate your advice on stretching our budget this way. — Downeast Frugal, Maine

Yes! Start growing from seed now — literally now, in winter. Propagating plants is part of the new paradigm for American yards — and a big money saver. Yet another advantage of straight species native plants is that, unlike many cultivars, they are fertile and true to type. Although you’ll probably want to buy seed initially, you’ll soon be growing new plants from the ones in your yard — either actively or passively or both.

Seeds are precious.

It’s an irony of ecological landscaping that native plant seeds are both precious and plentiful. When you are starting to transform a yard, seeds are precious. They are often hard to find commercially, especially if you’re looking for local ecotype.

Scarcity of native seed turns out to be a large-scale, national problem. According to a report published last week by the National Academies for Science, Engineering, and Medicine, there is insufficient native seed supply for recently funded ecological restoration projects on government land. Fortunately, the report’s comprehensive recommendations seem achievable.

Seeds are plentiful.

On the other hand, once you have native plants in your yard, they produce seed — often profusely. You can collect their seeds and use them to propagate, just as you would purchased seed. In addition, native plants often reseed spontaneously, producing “volunteers” as gardeners call them. They can also produce volunteers by sending out stolons (above-ground shoots) and rhizomes (underground shoots).

Traditional horticulture frowns upon such proliferation, breeding plants that keep to their lanes and planting them far apart to allow for spread. However, plants thrive together in community — and big gaps invite invasives and other unwanted plants.

A better approach is to plant young plants densely in a small bed, then expand the bed or create a new one from the seeds and volunteers those plants produce. If you’re transitioning from sections of lawn to beds of natives, you can replace a section of lawn, then extend or mirror it with volunteers or plants grown from seeds from the first bed. 

Pro tip: Plan to expand a bed’s width — along the path — not depth.

Maintaining a nursery

Notice that I said plant small plants, rather than seeds in the new bed? That’s because, initially, when seeds are precious, coddling them in a little nursery will substantially increase the chances they survive until adulthood. According to Robert Pavlis, who tests common garden “wisdom,” broadcast seed sowing — as you might do to create a meadow — has a survival rate as low as one percent. On the other hand, starting seeds indoors in a baggy and transferring sprouted seeds individually to small pots can yield close to 100 percent. I’m trying the baggy method right now with seeds I collected locally in order to monitor whether they germinate.

For your needs — starting a large number of species from newly purchased (and likely viable) seeds — I recommend the winter sowing method. It yields a significant percentage of seedlings and it’s easier than the baggy method. Just set it and let it. This is the method advocated by Maine’s Wild Seed Project, a great local ecotype source for your yard. I used their seeds and instructions successfully last year in Rhode Island; see my slightly adapted version below.

What to plant

In other issues of this newsletter, I’ve described how you can learn about local ecosystems, make a master plan, identify keystone plants, and develop a plant palette. You can find these columns by searching the archive at DearAvantGardener.com.

But if you haven’t already developed a plant list, wing it! Select a variety of whatever is available and recommended for beginning seed sowers, then see what thrives. For less than $250, you can buy seeds and materials for a germination nursery and grow hundreds of plants in just the first year. In subsequent years, you can grow more of those you come to love.

It’s an experiment. Have fun!

— The Avant Gardener

Why, How, Wow!

Why

If native plants are adapted to the conditions where they evolved, local ecotype plants are even more so. An ecotype is a genetically distinct subspecies that evolved in the conditions of a specific ecoregion. Choosing local ecotype seed increases the chances your plants will thrive in your yard — and maintains regional biodiversity.

Level III ecoregions of the continental US; source and expandable map at EPA.gov

How

Here’s how to create a home nursery for native plants. I recommend watching this video with Wild Seed Project’s founder, Heather McCargo, whose method I have adapted.

Locate your nursery outside on the east or north side of your house, close enough so you pass often during the heat of the summer and within reach of a hose.

Now through spring: Germination nursery

Starting in fall or winter, you’ll maintain a germination nursery. The instruction below include links to the materials I used to create the two-foot by five-foot germination nursery pictured above (#affiliatelinks). You can make your own variation with whatever you have on hand. Most supplies can be reused for years.

  1. Gather the supplies below, plus up to 36 packets of seeds.

  2. Place two six-by-six beams about 14 inches apart.

  3. Write the name of each plant in pencil on a label.

  4. Fill four-by-four pots with potting soil and arrange between the beams. Close ends or leave six inches for leaves to collect.

  5. Sprinkle one pack of seeds over each pot and insert label.

  6. Sprinkle sand to a depth equal to the width of the seeds (usually very little). Skip sand if the package indicates the species needs light to germinate.

  7. Unroll hardware cloth along the bricks and weight down with bricks or stones.

Set it and forget it. Let snow and rain fall on your little pots. By late spring, you will have seedlings.

Summer through early fall: Seedling nursery

Your seedlings will benefit from regular watering and protection from rabbits the first summer — maybe longer, depending on the species (and your location). My recommendation is to create an enclosed seedling bed. I created the pictured temporary nursery with more hardware cloth and metal stakes. Eventually, I expect to house my nursery in a more attractively enclosed area where we’ll also plant vegetables.

By early summer, many of your little pots will be bursting with seedlings, ready for a larger home. You can move these in a clump into a larger pot, where they will spread out on their own. Once they have deep enough roots, separate them into larger clumps or individual plants and plant them in the ground. Then monitor and water deeply — at least once a week midsummer if you don’t get rain; seedlings in pots may need supplemental water a couple of times a week.

Large, robust seedlings may be transplanted into a garden bed in the fall.

My New England seedling nursery in June last year

Wow!

Greg and Christine Van Zandbergen's front yard in Philadelphia’s Main Line, below, is a sea of native wildflower easily grown from seed: yellow coneflower (Ratibida pinnata), pale-purple bee balm (a hybrid of Monarda fistulosa), scarlet bee balm (Monarda didyma), and silvery mountain mint (Pycnanthemum muticum).  Note how well the turf area integrates with the perennial wildflowers.

Design: Refugia Design; photo: Ngoc Minh Ngo; source: marthastewart.com

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