One of the reasons we mulch our gardens is to prevent seeds of unwanted plants from germinating. Keeping ground covered and reducing disturbance is generally a good way to reduce maintenance.
But what if we want plants to perpetuate from seeds?
Fertile, self-sowing, open-pollinated plants are full of genetic diversity and food for pollinators. They often charmingly appear in places we’d never think to plant them.
What a great way to get more plants or perpetuate special ones, with little effort. It’s a lot easier to remove plants where you don’t want them than to plant anew – and cheaper too. I call it gardening by subtraction.
Despite a layer of bark mulch, the forest reasserts itself in the rich soil of my shady beds.
In late summer native pagoda dogwoods (Cornus alternifolia) are loaded with blue berries that birds go crazy over (see top photo).
When seedlings appear in my woodland beds, via seed-filled bird droppings, I transplant them under canopy trees. Black cohosh (Actaea racemosa) rambunctiously reproduces in these shady beds too, but enough already. I collect stalks with ripe seeds (photo above) and toss them up in the woods to establish deer-proof ground layer colonies.
SELF-SOWING PLANTS IN SUNNY SPOTS
Sunny beds can be a different story.
Years ago someone gave me cleome seeds, saying, “Once you have cleome, you’ll always have cleome.” I liked having a single color rather than the usual mix.
Neither Cleome hassleriana nor the Verbena bonariensis, Nicotiana langsdorfii, sweet alyssum or other classic “perennial annuals” I tried ever reliably reseeded in my beautifully prepared garden beds.
The “aha” moment came when I asked a gardener whose borders were bursting with these plants in bloom when my few survivors were barely even up. He said offhandedly, “Oh, everything seeds in gravel.”
In my sideyard garden, hot sun, sparse mulch, lots of disturbance and a path of grit and fine gravel that gets kicked around turned out to be the key to success.
Now desirable native perennials and classic cottage garden annuals make themselves politely at home year after year. Here are my favorites:
SELF-SOWING NATIVE PERENNIALS
- Nodding onion (Allium cernuum)
- Narrow leaf mountain mint (Pycnanthemum tenuifolium)
- Brown-eyed Susans (Rudbeckia triloba)
- Butterfly weed (Asclepias tuberosa)
- Anise hyssop (Agastache foeniculum)
- Spotted beebalm (Monarda punctata)
- Columbine (Aquilegia canadensis)
SELF-SOWING ANNUALS, BIENNIALS AND SHORT-LIVED PERENNIALS (NON-NATIVE)
- Jewels of Opar (Talinum paniculatum ‘Kingswood Gold’
- Breadseed poppies (Papaver somniferum)
- Patrinia (Patrinia scabiosifolia)
- Green flowered ornamental tobacco (Nicotiana langsdorfii)
- Brazilian vervain (Verbena bonariensis)
- Mulleins (Verbascum chaixii and unknown hybrids)
- Donkey tail spurge (Euphorbia myrsinites)