Earlier in life I enjoyed a lack of sensitivity to our old friend, poison ivy (Toxicodendron radicans). The allergic reaction to this plant can wax and wane throughout one's life, but most of us start out allergic and stay allergic, with the effects growing worse with each exposure. I had a friend that even got it in the winter, but I never did. Part of it was that I quickly learned to recognize it even at a distance, especially after noticing the resemblance to Fragrant Sumac (Rhus aromatica), a safe-to-handle ornamental native shrub. Check out this website here for some examples.

However. A few years ago (OK, it was 15) I was surprised by a nasty case that required a course of steroids to get rid of. Maybe doing that woodland cleanup on a humid day wasn't such a good idea? Now I dedicate myself to avoiding poison ivy at all costs. I didn't encounter too much of it in my suburban garden but out here in my country garden holy heck it is everywhere. The tricky part is to not only look for those "leaves of three" but those tell-tale rooty vines clambering up tree trunks, with no foliage at eye-level where you stand a chance of noticing it, until popping great big leaves in the canopy, blending in with your hardwoods. Don't lean on any tree trunks!

A major issue is that poison ivy foliage is extremely variable. The three-leaf thing is definitely an ID point, but the darn leaves can be notched or smooth, matte or a bit shiny. The one thing that seems constant is it's exceptional vigor - it looks green and healthy all season until it bursts into glorious fall color. And while poision ivy is usually seen as a vine or groundcover, it can get quite woody and shrublike with age.

Another thing that confuses people is that there are OTHER vining plants found in the same habitat. Can you reliably tell wild grape and woodbine (parthenocissus) from poision ivy? Another fooler - baby boxelder seedlings. Even I sometimes glove up to pull one, just to be on the safe side. But I will tell you, if you see white berries on a vine, you are looking at poison ivy. Incidentally those berries are a valued food for plenty of wildlife which helps explain why it comes up everywhere.

In other (unwelcome) news, climate change is is making poison ivy both more virulent and allergenic. Ugh. Climate change is making poison ivy stronger and itchier

To remove it one must either pull it or use Roundup (glyphosate). Sever the vines that are climbing your shade trees, treat the fresh-cut stump, and spray any regrowth that occurs. Forget those "organic" salt and vinegar recipes, it's just going to re-sprout, and salting the soil is undesirable. And you must never, ever burn it as the smoke is toxic. Goats eat it, so you could see about renting a herd of them to clean up your acre, like the City of Ann Arbor does. Keep a bottle of Technu by the sink, and in your work truck or garden tool bag for fast treatment if you think you've been exposed and you might save yourself a trip to the doctor for a steroid pack.

Genetically modified foods have gotten quite a bad rap in the past few years, something I attribute to both a lack of knowledge and a multi million-dollar marketing campaign by the Non-GMO Project. That innocent looking butterfly that’s seemingly plastered on everything from salt to bread is an enormous spreader of misinformation. To begin with, salt does not have any genes to modify so a “Non-GMO” label is a bit misleading! I’ll try to dispel some of the more outlandish claims here.

Claim #1: Genetically modified produce is not as healthy as produce that is grown organically.

FALSE. There has been zero correlation between Genetic Modification and the health of food. Foods that have been genetically modified actually have a much more extensive testing and trialing process than traditionally grown foods. Biofortification can also result in a crop that has more nutrients than those that are traditionally grown. Ex. Golden Rice. (a)

Claim #2: Genetically Modified Crops are more expensive to cultivate.

FALSE. While it is true that there is a slightly higher price up front, “the economic advantages associated with insecticide savings and higher effective yields more than outweigh the technology fee charged on GM seeds.” (b)

Claim #3: The use of genetically modified crops only benefits large corporations.

FALSE. Globally, most genetically modified crops are grown by subsistence and small batch farmers solely for the purpose of providing for their families and the surrounding community. The recently approved GMO Cassava plant in Kenya produces a root with about 10 times more carbohydrates than the average cereal. It can also be grown in marginal and drought prone areas which account for about 80% of the land in Kenya. (c)

Claim #4: Genetically Modified crops use fewer pesticides.

TRUE. Most crops that have been genetically modified have actually been modified to be more resistant to diseases and pests. For example, with Genetically Modified corn, scientists engineered it to contain a gene that excretes a protein to kill invading pests such as the corn borer, thus eliminating the need to be sprayed with an insecticide (d).

(a) Ingo Potrykus, Lessons from the ‘Humanitarian Golden Rice’ project: regulation prevents development of public good genetically engineered crop products, New Biotechnology, Volume 27, Issue 5, 2010, Pages 466-472, ISSN 1871-6784 

(b) The Economics of Genetically Modified Crops, Annual Review of Resource Economics, Vol. 1:665-694 (Volume publication date 2009) First published online as a Review in Advance on June 26, 2009

(c) Kenya approves disease-resistant GMO cassava

(d) Gewin V (2003) Genetically Modified Corn— Environmental Benefits and Risks. PLOS Biology

Early this spring I had the privilege of visiting the Desert Botanical Garden in Phoenix, Arizona, where I had my eyes opened to how many different varieties of agave there are. They reminded me of hostas back home.  Agave: loves dry heat and sun. Hosta: prefers shade and cooler temps. They are culturally opposite but have some things in common as a landscape plant. (For our Southwestern friends who think hosta is the agave of the Midwest... write your own article.)

They are both easy to care for, though agave may have an edge in that area. They do resemble each other somewhat and are both grown mainly for the look of their foliage. This foliage comes in all shapes, sizes and colors. Over 250 different varieties of agave are out there. Hostas on the other hand top 3000! Hostas come with many variations of the colors blue, green, gold, and white, with many combining these colors in variegated foliage. Agave have a similar palette, but also include some purple and pink and come in variegated varieties as well. When it comes to diversity of shape and textures, agave certainly seems to have the upper hand. Some varieties of agave reach sizes a hosta could only dream of.

The largest agave is Agave atrovirens. It can weigh a total of 2 metric tonnes. Each leaf can be over 14 feet long and weigh over one hundred pounds, and the flower stalk can grow over 40 feet tall. This may not be suitable as a landscape plant, but the Blue American is a gorgeous large landscape plant at 4-6 feet tall and 8-10 feet wide. These, along with other large varieties, can make the largest hosta feel inadequate. Leaves on agave can be wide or narrow, short or long, tightly packed or loose and open. The more you research the more amazed you become with the sheer variety

If I lived in more arid regions, I might miss certain plants, like hostas, but I could see myself joining the ranks of other obsessed agave collectors. Going to agave swaps across the southwest, scouring the internet for more varieties, drunk on my own home made mezcal. Deeper into the rabbit hole I would go, dabbling in cactus and succulents until I’m hooked on them as well. It wouldn't be long until I was involved in shady back alley deals trying to get my hands on the rarest varieties.

There would be an intervention most likely... to no avail.

 All photographs copyright David E. Baker.

…by planting native varieties and native cultivars.

Have you ever taken a moment to really appreciate our natural surroundings? Immersed as we are in smartphones and technology, I think we tend to forget to do this. I am often guilty myself, but I do enjoy walking through parks and woods and seeing the different oaks, maples, and other native species.

Our growing population has created a high demand for roads, parking lots, businesses, and housing. That land that was stripped to make room for a development contained its own habitat and ecosystem. Planting more native plants and native cultivars is a step to rebalancing the habitat that was lost.

What is a native plant?

This is a complicated question with much debate. Some believe it means plants that are untouched by man and naturally growing in the wild. You’ll encounter discussion on exactly where that “wild” needs to be to qualify as “native” for your particular project. Then there are native cultivars or “nativars”, which are selected, named varieties of native plants, with some improvement such as a more colorful bloom, nicer habit, or better disease resistance. It can be easier to source nativars than the original species, too as some plants do not lend themselves well to nursery production. You'll want to determine what the differences are from the original wild version to see if the improved one works in your particular project.

Benefits of planting more natives and nativars

• Once established they require very low maintenance.
• Often require less water.
• Attract and support native wildlife such as birds, butterflies, pollinators and more.
• Native plants help you use less fertilizers and pesticides.
• Already adapted to local climate conditions.

It is always a good idea to plant multiple different species and not all one variety. Doing this may prevent catastrophic loss in case a new disease or insect outbreak occurs, like the ongoing Emerald Ash Borer, Dogwood anthracnose, Boxwood blight, or Oak wilt situations.

Fun fact: A native oak tree supports over 500 species of caterpillar compared to the non-native ginkgo which supports only 5. Plant some oak, the songbirds will thank you. (Research by entomologist Doug Tallamy)

There are choices to make in any landscaping project. The microclimate can provide a place to start, then the considerations of general design and how much maintenance are one is willing to carry out, site traffic and usage, etc. Within the framework of your plans there are opportunities to go beyond visual enjoyment - your clients could actually taste the fruits of your labor!

Let’s begin by considering some plants that are readily available, or may already be in your design toolbox.

Aronia (Black chokeberry) is popular in Michigan landscapes. The white spring flowers turn into loads of nearly black berries which are eagerly eaten by birds. I encourage you to pick some for yourself - they may be exceedingly tart, but are tasty when added to sugary lemonade or made into jam. Consider Aronia m. ‘Viking’. Aside from the outstanding fall color, it's berries may be eaten right off the branch for an invigorating antioxidant-rich wallop to your tastebuds.

Agastache (Hyssop) is a perennial with aromatic leaves and flowers. There are blue-purple varieties and some newer cultivars in pink, coral, yellow or orange. Mix bruised leaves into tea for an alluring licorice flavor. Some varieties sway towards a mint flavor profile that I’ve enjoyed smashed into vanilla ice cream. Hyssop flowers make an enticing garnish in summer drinks.

Do you have dandelions in your lawn? Besides feeding honeybees, dandelions are a versatile culinary bonanza! Not only are the leaves an excellent salad green, but the flowers are edible, as well as the roots. Young flower petals have a honey-like flavor good in tea and jam, and the entire flower head may be sauteed in butter with garlic and eaten with a little salt on toast. Dandelion roots may be dried and brewed into a medicinal tea with many benefits.

Whenever discussing eating self-harvested plants safety must be mentioned. Always consider the plant and it’s surroundings. Pesticides, fertilizers, and any other runoff from the surrounding area will make it’s way onto and into the plants. Only consume a plant that you have properly identified and be sure to know the areas exposure to potential toxins.

If there is any doubt, do not consume it! 

These are some of my favorite edible landscape plants:

• Borage - Annual herb with star-shaped edible blue flowers.
• Daylily - Unopened flower buds can be eaten raw or cooked.
• Pansy - The flowers are often used as a salad or dessert garnish.
• Fruit trees and shrubs - Blueberries, apples, cherries, peaches, pears, etc.
• Honeyberry - (Lonicera caerulea) Large blue-black berries, used like blueberries.
• Lavender - Aromatic flowers and foliage with countless uses.

Perhaps the following recipe will inspire a patio conversation this summer.

Dandelion Wine

Boil 1 quart of rinsed dandelion flower petals in 1 gallon of water for 4 minutes, strain out and discard the petals. Allow the water to cool to under 100°f. Stir in 1 sliced orange, 1 sliced lemon, 8 cups of sugar (or 7 cups of honey), and 1 package of wine yeast and pour into sanitized plastic vessel, ideally fitted with a fermentation lock, but a towel and loose-fitted bucket lid will work. After 2 weeks decant or siphon into a secondary vessel or bottles and allow to age for at least 1 more week. Garnish with a freshly picked flower from your yard and enjoy the fruits of your labor.

Something so sinister, it will give you nightmares. Perennials and tulip bulbs will not be the only thing emerging from the ground this spring! I am talking about “Brood X” Cicadas. They are really not that scary, but their name makes them sound like something out of a horror movie.

The Brood X Cicada is a periodical Cicada. This fascinating insect spends nearly it’s entire life underground feeding on nutrients from the host tree’s roots. Once the soil warms up to 64 degrees - coming soon! - they will begin to surface from beneath the trees where their eggs were laid. Seventeen years ago, in 2004. There are different kinds of Cicada with different maturation cycles but just one that takes this long, and it is only found in the Eastern United States. The reason there are so many all at once (Millions! Billions?) is probably an adaptation to foil predators – there are simply too many to all be eaten.

You may see their exoskeletons on the side of your house or on the trees, left behind as the winged adult molts. There are annual Cicada that emerge every year in much lower numbers, and the low-pitched buzzing they make is a sound of summer. But if you think the yearly Cicada is loud, wait until this year! In Michigan, Hillsdale and Washtenaw Counties saw the largest population so we are in prime position to witness this phenomenon.

The red-eyed creatures may look intimidating but are harmless to pets and humans. Some areas with large pockets of these insects may see broken branches from younger, fragile trees or plants due to the sheer numbers of Cicadas. Not to be alarmed though, Cicadas cause minimal damage. Spending all but 4-5 weeks of their lives underground, they move through the soil and naturally help aerate it. After they arise from their chambers and molt, they have but one goal: to mate. That deafening sound is the call of the male Cicada. Once mated the female has a razor-sharp appendage to cut a V shaped slice into branches where she will deposit her fertilized eggs. The eggs take about a month to hatch into nymphs and fall from the tree to burrow and start the next 17-year cycle.

Ok, so maybe not so sinister or evil, but intriguing instead. Let us try to appreciate them for their short visit and loud noises after the 17-year long journey they have been on.

Check out these links for more information:

• When will Cicadas emerge in 2021? - USA Today
• Cicada fact sheet - Maryland Dept of Ag.

A recent article by my coworker Matt reminded me of this old saying. It’s born of the experiences of many rock and perennial gardeners. Throughout the years gardeners have collected and experimented with plants, looking for ways to use plants not necessarily accustomed to their soil type or zone. Their answer, in part, was raised rock gardens. Not only aesthetically pleasing, this approach created mini-climates in small spaces much in the same way mountain ranges create dramatic changes in flora from ridge to ridge. Lush forests give way to arid deserts on opposing side of the same mountains.

Rocks and raised beds give plants good drainage. Many perennials in the North die, not from cold, but from excessively wet ground conditions. Perennials such as Dianthus, Lavandula, Gaura, Thymus, et al. thrive in their first plantings only to rot during their juvenile winters. Perennials with long tap-like roots such as Lupines, Hollyhock, Foxglove to name a few die from crown rot due to excessive surface moisture. The fence post problem – solid above and below the ground but rots off right at ground level.

Ground-covering plants like Sedums, Ajugas, Thymus run along filling the crevices, encouraged by the cool, moist conditions. The seed of many annuals and perennials find some of these same places to spend their first winter, where they experience death and rebirth in the stratifying process. A true, natural nursery.

Rocks help ease the stress of extreme temperature change. In the summer they create cool, moist conditions on their down side. In the winter they warm with the sun, giving roots some protection against the cold. Gardeners were often able to include plants that were a zone less hardy. This also works for woody ornamentals that are usually considered sub-shrubs such as Buddleia, Caryopteris, Callicarpa, Hypericum, Crape Myrtle, and more. These types of woodies experience varying degrees of dieback but recover well from roots and heavier wood. Even just tucking hand-sized rocks around the base of perennials and shrubs can give protection and anchor the late-planted.

So when it comes to planting, if you’re ever in doubt, just go get one.

Photos © Holly Christensen, except mountain scene (Storyblocks)

In recent years, I’ve often heard that we should leave the first round of dandelions to grow and flourish for the benefit of early food for bees. You don’t need to tell me not to mow… done! That’s an easy way to help out our little winged friends.

As the movement to promote bees increases, it’s a good idea to have a pollinator plan ready for customers interested in this topical form of conservation.

For starters, since honeybees begin foraging when temperatures approach 50°, your plan needs to begin early. Minor bulbs such as Crocus, Winter Aconite, Snowdrops and Chionodoxa are valuable food sources on those first warm spring days when little is in flower. A few weeks later the Red Maples pitch in, followed by showy spring bloomers like Forsythia, Redbud, Amelanchier and Magnolia.

Mid-to-late spring has no shortage of excellent choices, as most of our ornamentals bloom then. As things taper off into summer, Monarda, Dianthus, and Echinacea offer long blooming periods that keep the bees happy. Late summer is more challenging but Rose of Sharon and Caryopteris are two species that bloom almost into autumn.

At the tail end of the season plants like Aster, Helianthus and Sedum are excellent fall bloomers. The beginning and end of the season are the most critical, as there are fewer food sources than during the peak of the season. If you’ve incorporated annuals into your design so much the better as they will go until either killed by frost or removed.

On the window sill in my office there is an ever growing collection of rocks. Most of them I've found around the grounds of Christensen's, some more exotic ones arrived in tree balls or were given to me by customers. Rocks have interested me since I was a kid. I had 'em stashed everywhere - dirty rocks in my sock drawer, jars and buckets full of rocks all over the yard, and a couple cool polished specimens were displayed on my dresser.

As I got older I wanted to know the stories behind the rocks, what they are made of, and how they came to be where I found them.

Michigan is a fantastic place for a rock-lover to reside due to an amalgamation of geological events.

400 million years ago this area was a briny tropical sea just north of the equator. As the landmass drifted northward jungles full of displaced plants and animals left behind rich soils and minerals, whilst retreating seas precipitated vast deposits of salt and sand. The ancient sea life produced fossils like Petoskey Stones and Crinoids in abundance that we find on our beaches today.

Michigan has something else going for it when it comes to cool rocks. Volcanos!! During the mid-continental rift fiery lava gurgled up great amounts of minerals from the molten belly of our planet. When liquid magma solidifies underground it becomes igneous rocks like granite and obsidian. Granite countertops are made of magma that has slowly cooled under pressure, allowing time for crystallization. A lot of the granite you'll find in Michigan has red in it. The red color comes from the iron oxide that’s mixed in with the feldspar and quartz. When lava cools above ground it hardens into extrusive types of igneous rocks like basalt and pumice. One of my favorite rocks is called pudding stone. It's a colorful conglomerate of red jasper, quartz, and other pebbles that have been metamorphosed into quartzite.

North America was once home to towering ice sheets over a mile thick. The Earth's crust was actually deformed under the weight of these ice age giants. As they slowly scraped their way down the continent countless tons of material were picked up along way (including my pudding stones). The massive ice sheets eventually settled in our Great Lakes Basin and melted, releasing rocks and debris that span both geography and time.

The combination of glacial transportation, continental drift, and volcanic upheaval have led to perhaps the most splendid mixes of rocks of anywhere in the world.

My parents instilled in my family a sense of stewardship over nature that has stuck with me through the years. As we grew up in Northern Michigan, we were taught to recycle, use our grandmother’s compost pile, and practice "Leave No Trace" camping and hiking.

As an adult I’ve tried to expand on these lessons to be as Earth-friendly as I can in the current day and age. I keep my water bottle on me to eliminate the need for single use cups, I’ve found ways to reduce my carbon footprint, and I try to support sustainable businesses.

All of these things help, but the biggest way to help the environment are the three R’s: Reduce, Reuse, and Recycle.

The first R: Reduce. This one is probably the easiest to accomplish. There are so many ways to reduce the amount of waste that your household produces. Single-use plastics are the biggest household pollutant worldwide. Reusable sandwich bags and storage containers are an easy and affordable way to cut back on single use plastics. Even just bringing reusable shopping bags to the grocery store can help cut down on the roughly 1.8 billion plastic bags that are disposed of each WEEK in the United States. Keep in mind though, that just like other reusable storage, reusable grocery bags do need to be washed regularly. Swapping out beeswax wraps for plastic wrap is another great way to cut down on single-use plastics.

The second R: Reuse. Keeping and reusing things like boxes and gift bags is a great way to prevent waste. I also like to save glass jars from foods that have been used up. If you soak the labels off and wash them out, they’re great for holding pantry staples like coffee beans, rice, and dried beans. Glass jars also work great as small planters; line the bottom with lava rocks or gravel for drainage before filling up with potting soil and go for it! Another simple way to reuse things is taking old t shirts with rips or stains and cutting them up to make rags for cleaning and dusting.

The third R: Recycle. Recycling may seem like the easiest thing on this list, but many municipalities have stringent guidelines for what can and cannot be recycled which aren’t always clear. I live in the city of Detroit, which doesn’t necessarily have a citywide recycling program. Now as I have to sort and take my recyclables to a processing plant myself there are a few things to remember. First of all, any cardboard or paper that has food on it cannot be recycled. The same goes for containers that have not been thoroughly cleaned out. The most commonly recycled plastics are plastics #1, #2, #4, #5, #6, and #7, so make sure you check the numbers before blindly throwing things into the bin! The biggest lessons here are to check your local guidelines before trying to recycle things.

Working as we do in the Green Industry makes us a natural fit for modeling environmentally-friendly practices both at work and at home. Our families, clients, neighbors and friends can be positivly influenced by our example.