Archive for Wednesday, August 30, 2017

Down to earth: Battling garden thugs

August 30, 2017

I have been harboring fugitives in my garden.

Lamium galeobdolon, a.k.a. yellow archangel, Lysimachia clethroides, a.k.a. gooseneck loosestrife, Physalis alkekengi, a.k.a. Chinese lantern, sweet annie, lemon balm and sweet autumn clematis to name a few.

I have always called them invasive plants, but I recently learned from Johnson County Horticulture Agent Dennis Patton that this term is reserved for serious lawbreakers: alien species that escape the confines of our cultivated yards and gardens.

They find their way into nearby prairies, woodlands, and waterways where they spread rapidly and out compete native plants and trees that support wildlife and insects. They include the Bradford Pear, mimosa, burning bush and purple loosestrife.

Janet Rossbach

Janet Rossbach

The plants that cause extra work for us home gardeners Patton refers to as garden thugs.

You probably have a couple of these bad boys in your own garden. They are appealing because they often flourish in problem areas like our clay soil or in deep shade where other plants can be hard to establish. They may be quite beautiful, too.

Gooseneck loosestrife (not related to purple loosestrife) has an unusual arching bloom, made up of many tiny individual white flowers that does indeed resemble a goose or swan’s graceful head and neck. It thrives in sun or shade and spreads by underground rhizomes. It is impressive in a clump and makes a lovely and long-lasting cut flower, but it can take over a bed before you realize it has displaced other plants that used to grow there.

Yellow archangel has an attractive variegated leaf and a yellow, orchid-shaped bloom in the spring. It will quickly cover a shady patch of ground under a tree by sending out runners, or stolons.

Along these stolons are nodes that send down roots and voila! You have a clone of the original plant.

Other species that spread this way are ajuga, strawberries, creeping jenny (Lysimachia nummularia), and many grasses.

Garden thugs are usually well behaved for the first couple of years.

In fact, the first year they probably won’t flower or may even die back completely if you have planted a division.

The next year they might do so well you decide to divide your own plant and move a bit of it over here and some over there. Be careful; you have just let this botanical bully out of its cell. That’s how Chinese lantern wound up in every bed in my backyard.

As a Master Gardener friend said about plants like these, the first year they sleep, the second year they creep, and the third year they leap.

Some of my favorite offenders can be a nuisance by prolifically self-seeding, notably, larkspur (Delphinium consolida) and sweet annie or Artemisia annua. Both emerge in early spring and their feathery lime-green foliage looks similar.

Sweet annie however can be identified by its wonderful piney smell (which it retains when dried). It grows rapidly and can reach a height of six feet. In early fall it develops tiny yellow flowers, which is when I cut it for drying.

Whatever I leave in the garden will go to seed and we are talking thousands of seeds, so if I don’t want it coming up everywhere I must pull or dig most of it up before those seeds set.

Larkspur blooms in spring, sending up tall spires of purple blossoms along branched stems.

If I have let dill self-seed the previous year, the larkspur grows in tandem with the dill and its lime green globes are stunning with larkspur’s purple flowers.

By early summer larkspur’s oval pods fill with seed and when they turn brown and split open they spill thousands of round black seeds wherever the leaning stalks have positioned themselves, including onto the lawn.

I love these old-fashioned self-seeders and wouldn’t be without them. When they are coming up in the spring they can carpet an entire patch of ground and are easily pulled up but I confess I’m a lousy warden; I’m often too indulgent and let them stay until they start crowding out other plants.

I will vow to keep in mind something I heard at my last garden club meeting: It’s not against the law to throw away a plant!

It becomes a challenge to keep trespassers from invading the space of better-behaved plants, one that requires equal amounts of muscle, sweat, and ruthlessness.

I am determined to meet this challenge without using chemicals, so at least for now I try to stay ahead of the game and rip them out early in the season, be vigilant as they continue trying to claim new ground as summer comes on and finally be careful not to let them drop their seed where it will lie unnoticed until next year, when the battle between the garden thugs and me will begin again.

-Janet Rossbach is the co-vice president of the Garden Club of Shawnee


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