Nonnative Species V. Invasive Species

There are many garden species, common day lilies for instance, that: oblige the grower, spread but can be removed, and do not cause problems for adjacent wild areas.

Then there are the really invasive plants that will find disturbed areas and take over to become a destructive monoculture. Buckthorn and garlic mustard are not very good for the local wildlife species to eat, but will spread, especially to disturbed areas. I garden a small area of land near an urban center, formerly grass. Buckthorn and garlic mustard consider my disturbed area a playground. Garlic mustard is very clever, it finds it’s way to every open space here.

A funny thing happens when you pull out garlic mustard on a recently invaded creek bank. Other species that have been growing there, have been crowded out by the garlic mustard are still growing in between. Garlic mustard is a pest, it is a self serving, spreading invasive with the ability to create a monoculture of itself.

Local chefs have developed recipes for garlic mustard. Planting it is not good, but in areas where it is taking over, garlic mustard lasagna is reputed to be served in spring.

Here in Michigan there is interest in looking after our remaining wild areas, and in reclaiming degraded areas. Garlic mustard pulling is a common spring pastime.

Another notable invasive species here is buckthorn. Introduced as an ornamental, buckthorn is a small tree or large shrub, it will take over an area and when it does, nothing will grow in the understory. It out competes everything. We stopped mowing the lawn near our creek and buckthorn created a buckthorn monoculture in 10 years. There was nothing growing there but buckthorn. (I have since removed it, and must remain ever vigilant, removing young plants) Some stewards will resort to chemical control, making a special wand and cutting the trunk about a yard above the ground, smearing the stump with glycosol and walking away. I personally do not use chemical solutions. I use the method of mechanical sawing and remove growth from the stump at least twice a year, the buckthorn stump will not survive consistent leaf removal.

I have seen large piles of sawn buckthorn bodies in parks, and I have seen more reserved approaches to buckthorn removal. Buckthorn has a male and female plant, the destructive berries that will plant themselves and spread all over appear only on the female plants. Female plant removal is a priority.

Phragmities is also a problem around lakes and in ditches along freeways were there is runoff. There is a native phragmites, but it is small.

Humming Bird at the Choral Bells

Humming bird at the Choral Bells

We used to see humming birds when we lived in the city, three miles from Rouge Park. My neighbors put in red salvia every year and that is where they dined. Today I saw a hummer at my pink choral Bells.

This year I have made an attempt at planting cardinal flowers. These reaquire some stratification (Cold). I did put the seeds in the refrig. but maybe need to put the planting medium in too.

My neighbor to the east has a pot full of red salvia. As he pointed out: hummers need a whole lot more than a pot full of flowers.

I am seeing hummers and monarchs as rangers, going far and wide to find sustenence, perhaps reporting back to headquarters on what they find. How else could they survive, I’m wondering, excpt by working together.

At Wilderness State Park last year, I saw one cardinal flower in bloom. A tribe of humming birds would have to have sharp eyes to find it, among the trees, by the river.

I have a hankering to range far my self, go to Ann Arbor farmer’s market, maybe or even up to Mason, Michigan to Wildtype Nursery, and purchase cardinal flower and other wild lobilia plants. Not that I have had that much luck with them but a gardener has to keep trying.

Letter to Urban Homeowner

I was thinking of you and Laura and about your new digs. I googled rain gardens, noticing that Wikipedia now has a most comprehensive entry on same. The only quibble I have is the percentage of compost (80%) recommended for backfill. I have seen all but the most heavy soil (we have such clay here in the metro area) not require excavation only digging or finding a low area on the property and directing the water there. The most elegant way I know of is to dig a depression and put an inch or so of compost on it, adding compost from time to time, planting deep rooted plants (natives are often preferred); but I have seen rain gardens that would not drain and become ponds. I have also seen properties with two feet of water in the drive, and the drive became dry when a rain garden was made on the adjoining land. That project was in Huntington Woods and the city provided a back hoe to remove the soil to two feet below grade and replace it with compost and sand. 

Each installation is different. I am sure that you will require a few rotations of the seasons to get a handle on what is desirable for your situation. Managing water in your new area to your satisfaction will take a few years, I'm pretty sure. Living near an urban river is both exhilarating and sad, sad in that you become cognizant of the damage occurring when developments upstream tear off top soil and vegetative cover, build impervious surfaces. New developments often cause problems for those living with the extra runoff downstream. Sigh. Hopefully in the coming years we as a society will be able to mitigate some of this damage. To mandate Rain Gardens or other bioremediation seems a reasonable solution. There already exists heroic and wonderful technology toward this end. It seems to me an up and coming area of adapting, but I have been wrong before on what will catch on in the popular imagination. 

If your urban soil has become contaminated with heavy metals (chances are it has lead in it if your neighborhood was developed before 1972, as that is when lead was outlawed in gasoline) there are plants (Sunflowers are great heavy metal uptakers) you can plant. Opinions vary on whether your plants out then to be land filled as toxic waste, or burned and the toxins removed, or composted. I cross my fingers and compost, but I live in a 60's ranch. 

Heavy metals and urban gardens

One of the trusty garden blogs I follow noted that Mother Jones Magazine had an article about lead content in the White House Garden soil. Lead is a problem for urban gardens, and in places that were cities before the 1970’s when leaded gas was still legal.

As an urban gardener I have been cognizant of lead issues and other heavy metal contamination issues. These should not ne ignored. Googling bioremediation, one will sooner or later find charts and information about what plants will take up what heavy metals.

Sun flowers, are workhorses in the bioremediation line. I compost a lot, and have not yet developed protocols for my own garden in respect to what to do with plants that will take up heavy metals. Some folk have burned plants and looked for heavy metals, the science is not well developed or widespread. I am counting on universities who have the lab space do this research and develop protocals.

For urban gardeners, and probably for all of us, developing testing for our soils and bioremediating is an important consideration. It is important to grow food meatime, as universities and others get to work on this important consideration.

One more note: most of us have toxics and heavy metals in our systems. It is virtually impossible to live on the planet in the 21st century and not have.