Sustainable enough

I just listened to an informative interview with Uli Lorimer, director of horticulture at Native Plant Trust, our local native plant society in Framingham, Massachusetts. Uli was a guest on garden writer Thomas Christopher’s weekly radio show and podcast, Growing Greener. Thomas focused the interview on native and locally adapted plants.

Monarch on New England aster

    Together, the two men proposed a type of garden that’s designed to serve the interests of as many living things as possible, not just humans. Instead of choosing plants because they’re pretty, you’d select what performs the most useful functions for your garden ecosystem. You’d put aside neatness as a top aesthetic priority.

Goldenrod is a key player in this meadow ecosystem in Maine

    This is the path I want to follow, but I argue that we don’t all have to arrive right away. Uli pointed out that much important information about native plants hasn’t yet been ascertained, and the rest hasn’t spread past native plant enthusiasts. As a start, he suggested, growers should be using plant labels to tell where plants came from and how they were propagated.

A plant label that lists the seed source and nursery location

    Native Plant Trust advocates growing plants that evolved in the local ecoregion, the area with the same environmental conditions they'll find in your garden. In addition, they value genetic diversity within each species, meaning plants that are grown from seed, not cloned through cuttings or divisions to be genetically identical. 

    A genetically diverse, locally adapted plant population will be well-equipped to deal with shifts in its environment, including rapidly changing climate. But so far, conventional growers haven’t figured out how growing from seed could be scaled up to their volume of production in a financially viable way. In addition, we consumers have been trained to want reliably uniform plants, which is what you get with clones. Seed-grown plants are variable. 

Mass produced plants are genetically identical and uniform

    Native Plant Trust sells about 300 species of locally adapted native plants at their garden shop. They’re grown from ethically collected wild seed of known New England provenance. But what if the shop doesn’t offer a native plant you’d like to buy? Is it wrong to buy plants that don’t meet their high standards?

    This brings me to my point. I think becoming a sustainable gardener, and a native plant gardener, can be a process. You don’t have to change everything all at once. After 35 years, my garden is full of nonnative plants I’ve chosen over the years. Many of the ones that have survived are plants I love and wouldn’t dream of removing. We have a history together.

They'll have to pry my nonnative white bleeding heart from my cold dead trowel

    Every year as I learn more about native plants, I add more of them to the garden. I adjust my gardening approach to accommodate their needs and welcome a richer population of wildlife, especially insects. Is it still OK to buy nonnative plants because you like them, or North American native plants even if they’re not local, they’re “improved” cultivars of native species, or they’ve been propagated asexually? I think it is. If we’re thinking about these issues, we’re moving toward full sustainability, even if we’re not there yet.

Newly planted mountain mint from NPT--native, locally grown and adapted

 

Sowing diversity

It’s seed-starting season, and I’m about to start my second round of annual and vegetable seeds. 

Time to plant some more seeds

With this in mind, I was eager to hear a talk this week by Randi V.W. Eckel, an entomologist and founder of Toadshade Wildflower Farm in New Jersey. She made the case for starting native perennials from seed and then offered some pointers on how to do it.

    Entomologists advocate growing native plants in our backyards, because native insects are adapted to live off them. 

Native plants feed native insects

Randi also pointed out that seed-grown plants are genetically diverse, whereas perennial plants that are multiplied by division, cuttings, or tissue culture are clones—genetically identical copies of the parent plant. In diversity, there is strength.

    My experience with seeds comes from common vegetables and flowers bought from large mail order seed houses. I was surprised to learn how different it could be to work with seeds of native perennials. Think they’ll all sprout around the same time? Think again—it’s adaptive for them to spread out their germination times so that one disaster won’t wipe them all out. It turns out that predictably timed germination is one of the characteristics our tame seeds have been bred for.

    Randi listed at least nine special requirements that seeds may have for germination, all adaptations that improve their chance of growing into successful populations in the wild. Some require periods of moist cold conditions, some dry cold, some alternating periods of warmth and cold. Some need their seed coat “scarified,” which can be done by scratching the seeds with sand paper (I wholeheartedly agree with Randi’s point that oft-repeated advice to do this with a razor blade is a recipe for losing a finger).

Seeds of blue false indigo (Baptisia australis) need scarification to germinate

     I think I know now why I’ve never been able to grow common milkweed (Asclepias syriaca), although I’ve brought home seeds with their silky parachutes several times when the pods opened in fall.  

Seeds of common milkweed are equipped to travel

Although this plant is usually regarded as a weed, I like the idea of its attracting migrating monarch butterflies. Monarchs lay their eggs on milkweed because it’s what their larvae need to eat. I pictured a gleaming orange and black monarch emerging from its chrysalis in my yard. Wouldn’t that be cool!

Monarchs are milkweed specialists

      Right now I’ve got a flat of unfortunate milkweed seeds mostly failing to sprout under lights in my kitchen, this time from a packet I was given by a friendly seed collector last spring. Randi pointed out that milkweed seeds need light to germinate. I shouldn’t have been covering them with soil outdoors or growing medium indoors. 

Luckily these milkweed seeds got enough light to sprout. I planted the rest too deep.

    So when I start this week’s seeds, I’ll try sowing milkweed seeds on top of the growing medium. But Randi’s talk convinced me to keep buying most of my native perennials from nurseries like hers. Let the experts provide the care the seeds and young plants need. If my native perennials succeed in multiplying in the garden, so much the better.

Sustainable-enough potting mix

To test the usefulness of my homemade potting mix and compare it to commercial products, I’ve been working this winter on propagating African violets. I made the potting mix to avoid using peat, which I learned is not a renewable resource. The mix is half compost from my yard and half coir, or coconut fiber.

    Like so many of my gardening methods, it’s “sustainable-enough” rather than ideal. That’s because the coir comes from Hawaii, accruing significant carbon cost on its 6,000-mile journey to Massachusetts. On the plus side, coir is a byproduct that I can put to good use, and compared to depleting peat bogs, which are major carbon sinks, I think non-local coir is the better alternative.

    I’ve had luck with African violets as houseplants probably because they tolerate neglect. My collection has been living for years on pebble trays next to an east-facing window. Their winter blooms are a morale booster. I’ll betray my amateurism by admitting that I haven’t kept track of the names of the varieties I’m growing. My favorite has blue flowers and purplish foliage. 

The pink ones are nice too.

    I wanted to try multiplying my collection by rooting single leaves. I cut off a few with stems about two inches long and stuck them into moistened potting mix in November. I enclosed them in plastic bags for a humid environment and put them under a grow light in the kitchen. Nothing happened for many months.

    Meanwhile, I discovered an excellent youtube video demonstrating how to propagate African violets from leaves, made by an anonymous benefactor who obviously knows what she’s doing. After watching her demonstration, I was able to start a new batch with several improvements in my technique.

    First, since the new sprouts grow from the cut end of the stem, I cut the stems shorter. I used smaller pots and didn’t tamp down the potting mix. I learned to cut the stems at a slant for more surface area and to cut the leaves in half to encourage them to put their energy into reproduction rather than photosynthesis and leaf enlargement. 

    This week I noticed some little leaves growing up at the base of the old ones in both batches. 

I took the pots out of their plastic bags and gingerly dug out the mother leaves. Voila! There were little plantlets growing from the cut ends. The new leaves were no more than a quarter inch long, some much smaller, but they had their own roots. 

 

    I pulled the babies away from the mother plant, doing my best not to break them. I planted the best ones in a recycled six-pack from last year’s garden center annuals, 

encased them in another plastic bag, and replaced them under the grow light. With luck, I’ll have reasonable-sized plants to enjoy or share next winter.

    The non-peat potting mix did its job just as well as the peat-based mix I used to use. Score one for sustainability.