Beware of Greeks bearing gifts

One of my biggest gardening mistakes was planting smooth Solomon’s seal (Polygonatum biflorum). This seemingly modest woodland plant aims for world domination. Now I’m trying to beat back its onslaught.

Smooth Solomon's seal emerges in spring

    I first encountered smooth Solomon's seal in the shade plant section of my favorite garden center. At the time I was coming to grips with the fact that I was gardening in shade. I was delighted to discover lots of plants with pretty foliage in a shady corner at the far side of the sales area. Smooth Solomon’s seal caught my eye because of its arching stems, shiny leaves, and pendant cream-colored flowers. 

Seemed like an understated, elegant woodland plant--photo Peter Gorman

I didn’t seek out native plants at that time, but since it was a North American native, that must mean it wouldn’t run wild, right?

    For several years I thought I’d picked an excellent plant for shady areas where nothing else wanted to grow. About ten years in, though, I noticed that smooth Solomon’s seal was showing up in every shady part of the yard—and that’s most of my garden. Its little blue fruits must have been making their way to new territory. In retrospect, I might have been safer with an attractive Eurasian cousin, fragrant Solomon's seal (Polygonatum odoratum ‘Variegatum’), which has a pretty chartreuse border around its leaves and seems to be less spreading—so far.

A more sedate Solomon's seal? Or crouching to spring

    It’s not too hard to dig out smooth Solomon’s seal. When you do, one reason for its success in dry soil becomes obvious. It has big fleshy rhizomes, underground storage organs that look capable of storing plenty of water and nutrients. 

Rhizomes store supplies for hard times

I’ve learned not to throw these or the blue fruits on the compost pile, because both produce new plants. Moving compost around, I may have unknowingly carried them to new areas of the yard. 

Fertile fruits of smooth Solomon's seal

Instead I now send them out as yard waste, to be cooked at weed-killing high temperatures at the municipal composting site.

    There’s a crabapple tree that I look at every day from our kitchen windows. I’d sure like to grow other shady woodland flowers under it, not just smooth Solomon’s seal. 

A pot of elephant ears attempts to disguise rampant smooth Solomon's seal under the crabapple

What holds me back from ripping it all out is the fear that I’ll kill the tree in the process. I once read a sad story about a man who killed a beloved dogwood by digging among its roots to surround it with daffodil bulbs, and I think I executed a venerable Japanese andromeda (Pieris japonica) when I pounded plastic edging through its root zone.

     So I’m removing the unwanted smooth Solomon’s seal cautiously, bit by bit. Last spring I dug out a wedge-shaped patch of it from the tree trunk to the drip line. This fall I did the same in a slightly larger wedge, arguing that the tree was ready for this because of our wet summer. Time will tell whether I went too far.

A section cleared of smooth Solomon's seal-- for now

    The main remedy will be to plant something else that can stand up for itself in place of the plants I tore out. Smooth Solomon’s seal abhors a vacuum.

Attention friends: I'll be speaking at the Massachusetts Horticultural Society's Ecological Gardening Symposium on November 8 at Elm Bank in Wellesley, MA. Here's a link to the program information. I'd love to see you there.