As a movie and TV enthusiast I often re-watch older episodes before enjoying the new season of a show or the next movie in a series. You know how you always see a few things that you didn’t remember from that first viewing? The same can be said about a company’s policies, practices, or procedures. Forgetting how to start a machine is just embarrassing but forgetting how to install or maintain something can be very costly. So, let’s go back a few episodes and review, to see if there is something that you may have missed or forgotten.

My favorite rerun episodes are about polymeric sweeping sands. There are many new and improved types of polymeric sand on the market, and I would count on there being more in the future. Some of the new features include being rain safe in so many minutes, dust free, haze free or allowing installation while the product is wet. All these features are great, but there are still some fundamentals that you need to remember. Here are some of the highlights:

• When you are applying and sweeping the sand into the joint, be careful not to overfill. In most cases you want to have the sand be 1/8^th of an inch from the top of the paver. Exceptions are cobbled types of pavers where you may want even less sand in the joint to bring out the cobbled appearance. You can always sweep out the excess when it’s still dry, that's a lot harder after it has been wetted or has set.

• Work in sections when applying the water. Even though many products have a single watering procedure, do not get carried away and water huge portions at a time. The watering process is the most essential step and adding too much or too little water because you lost track of where you did or did not cover could end in disaster.

• Speaking of watering, read the instructions fully and carefully. Did the brand you’re using change formulas or best installation practices? Have they added a feature that you were unaware of, or taken one out? Is this the right product for your application? You will not know if you do not read. If you have questions, always feel free to call the Hardscape Center for advice and guidance.

• Understand how your product will work on your site. Consider things like humidity, dew points and temperature. Is the project in the sun or the shade, is there irrigation near that may hinder the curing time? To fully cure, the product must completely dry after installation. If it does not dry, it will not cure. Uncured sand can wash out, swell up from excess water or have the polymers seep out and stain the pavers.

There are many more things to consider when applying polymeric jointing sand, but the above are the most common issues that I hear about. All the above can be prevented or addressed, and all are costly if forgotten about. Typically, the sand is the last part of the project and could be the hardest thing to fix. It never hurts to get a refresher on the installation of this essential step. If you have any questions or concerns do not hesitate to call. The next season is upon us, so grab some popcorn and take the time to review before you get lost by episode #2. Stay tuned for previews for the next show with limited commercial breaks!

If there is one plant every landscape should have, it is the peony. This handsome perennial is long lived and easy to grow, given a site with at least half a day of sun and decently well-draining soil. They are stunning focal points in mixed beds, or as the backbone of a perennial border, and belong in any style of garden from farmhouse to contemporary. Once I saw a row of peonies in full bloom running up a long driveway. I almost went off the road. The hard part is choosing which ones to plant. 

Peonies come in three types. The first, and earliest to bloom, are the woody-stemmed tree peonies (P. suffruticosa). The second are the fully herbaceous garden peonies (P. lactiflora, officinalis, and others), and the third are the intersectional peonies that are basically a cross between the two. Today's post is about the garden peony, the best known and easiest to find.

Let's dive in! Peonies have been cultivated for thousand of years and that means there are thousands of cultivars to choose from. Colors range from the purest bright white, to ivory, coral, pink - allllll the shades of pink - into fuchsia and finally, red. No matter which colors you choose, they all go together, so feel free to mix it up. The proper planting depth is key to getting flowers, so be sure to get those eyes no more than 1.5 - 2" deep. 

Peonies also come in a variety of different flower forms. My favorites are the wide open Single and Japanese forms, with bright showy centers, followed by the Anemone type that have a contrasting center fringed by wide petals. Other forms are Double, Semi-double, and Bomb. Many cultivars are fragrant, too. The earliest blooming ones kick off the season in mid-May, and by planting different cultivars you can go until late June. 

You may have heard that peonies, once planted, do not like to be moved. It is true that they are happy to stay in your garden for decades, but they can be transplanted successfully if you - like me - decide to move and can't bear to leave them behind. I've had my 'Sea Shell' peony for a good thirty years and she's doing great in her new garden.

Here in SE lower Michigan we have an amazing resource in the Nichols Arboretum Peony Garden (Ann Arbor), which has a massive collection of herbaceous peony, many of which are heirloom varieties. It has to be seen to be believed! Admission is free and the prime time to visit begins around Memorial Day weekend. You'll come away with a burning desire to plant peonies everywhere you can get a shovel in the ground.

• Nichols Arboretum Peony Collection Website
• American Peony Society - Herbaceous Peonies
• Peony Flower Types - American Peony Society (PDF)

All good things in life come from a bulb, isn't that how the saying goes? Okay, maybe not, but that is certainly true with Lilium! Planted in the spring (or fall), and returning every year, lily bulbs come in many different colors, and sometimes have a speckled or brush stroke pattern.

Lilium (Garden lilies) begin blooming in late spring, beginning with the Asiatic hybrids, and the distinctive fragrance of Oriental lilies on a summer breeze is sheer delight. With a little planning one can have lily in bloom for much of the season.

At Christensen’s Plant Center, we carry many lilies. One favorite is the Asiatic hybrid ‘Matrix’. This dwarf variety will only get 16” tall, and is a vibrant red with an orange brush mark in the center. We also carry tried-and-true Oriental Lily ‘Casa Blanca’ which gets 3-4’ tall. The highly fragrant pure white blooms are perfect for a classic look.

This year, we’re excited to offer three new Lilium combination pots. We’re loving the Asiatic Pot Lily Looks™ ‘Patio Sunrise Combo’ featuring yellow, pink, and orange dwarf varieties (14-16”). This will give you a fun mix that is perfect for a patio planter or cut flower bouquet.

The second is Asiatic Pot Lily Looks™ ‘Bloom Extensions™ Orange’. Lily flowers, though stunning, are usually short lived, but with Bloom Extensions™, you could get over 6 weeks of color. Two orange-flowering varieties, carefully selected to harmonize, have been potted together. The flowering times are offset, giving a seamless show of color. This is a great way to extend the display in your client’s landscape. This is an ultra dwarf combo reaching only 12-14”.

The third is Asiatic Pot Lily Looks™ ‘Bloom Extensions™ ‘Red & Yellow’. This stunning pairing of the yellow and red-speckled ‘Tiny Nugget’ (early, 14”) and the deep red ‘Tiny Rocket’ (later, 16”) is a real showstopper.

All the Lily Looks™ varieties have been selected for massive flower production, a short, compact habit, and suitability for container growing. Quantities are limited, and the grower has sold out - don't miss these! 

Whether you are looking for something unique or classic, our selection of Lilium has just what you are looking for.

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.

Do you buy a fresh Christmas tree? I do. Still a traditionalist. December 2020 was a "stay at home" year which meant Christmas tree shopping. Boy did I get a surprise, not just sticker shock - but finally on our third stop I found a tree “I could live with”. I tell this story because the scarcity of all evergreens is scary. Not just cute sheared Christmas trees, but 6’, 7’, 8’, and up, Colorados, Black Hills, even Chamys (can’t spell that word – it would make a great password). Soon Arborvitae? Then…? Get them as soon as you can and lock them up!

Unfortunately plant material in general is going to be scarce. 2020 was a boom year for “gen-whatever” to plant or get planted for yard fun. 2021 is going to be identical – just much harder. No, not harder – “more interesting”, as Tim would say. You might want to come to pick plants with a couple of options. Knowing which is more important: size? color? or location. If your customer really has to have “THAT” plant make sure they know, they may have to wait for “THAT” plant to grow up a little!

We are prepared!! We are working hard to make sure your job is easier. Remember: dull is well, just dull, but “more interesting” has sparkle.

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.

Color theory is both an incredibly simple and an undeniably complex concept. In the most basic sense, it is the art and science of using color.

The three fundamental tenets are the color wheel, color harmony, and color context. Using these tenets you can create a vibrant and well-balanced landscape that influences the mindset of the viewer. Read on for some examples.

The color wheel

Let's begin with the color wheel. You have your primary colors of red, yellow, and blue. Each primary color has many representatives in the landscape whether it’s the electrifying red of a Crocosmia 'Lucifer', the sunny yellow of Hypericum, or the cool blue of Delphinum, blue spruce, or the exotic Meconopsis. Next up you have your secondary colors: green, orange and purple. Obviously there’s no shortage of green in the landscape, from the uniform green of an oak tree, to the variegated green of the Hosta 'Guacamole'. Orange is slightly more difficult to find. Butterfly Weed, Echinacea, and Daylily come to mind. Don't overlook plants that bear bright orange berries, such as Little Goblin® Orange Winterberry Holly. Purple is an easy find, from flowers like Iris, Phlox, and Campanula or foliage of Cotinus, Weigela, Heuchera, and Ninebark. So many options.

Color harmony

Color harmony can be a difficult thing to achieve. In essence it engages the viewer and creates an inner sense of order. Basing your color scheme on complimentary color pairs such as red/green, yellow/purple, or blue/orange creates contrast and stability. Or you might choose analogous colors, meaning colors that are side by side on the color wheel. Typically with an analogous color scheme, one color will dominate, one color will support, and one color will accent. So combining say, a bright DoublePlay® Candy Corn® Spirea (yellow-orange), Hyperion Daylilies (yellow), and 'Frances Williams' Hosta  (yellow-green) creates a wonderful gradient that works well together. Use a primary color to draw the eye to a focal point and two tertiary colors to add dimension.

Another option is using triadic colors, where the colors are spaced equally around the color wheel, for example: 'Ruby Spice' Clethra (pink), Vinca (periwinkle), and Aruncus (cream). Triadic color schemes make each individual item stand out yet still feel balanced.

Color context

Using color to create context in the landscape is relatively simple when you know what each color reflects. Warm colors (colors created using red and yellow) reflect happiness and energy. The color red itself has been show to raise blood pressure and respiration in humans and can have an overwhelming effect if used improperly. Yellow conveys a sense of happiness and permanence. Cool colors typically convey relaxation and calm. Green is a very stable color and can add harmony to most color schemes. Shades of blue can vary greatly from calming to strong and reliable. Purple is associated with creativity and imagination in most of the world, and is also widely recognized as the color of royalty.

During the COVID-19 shutdown this spring, I was sitting on my porch on what was to be a beautiful day. It was early, and therefore quiet, and I heard a sound coming from my boxwood. I leaned in and distinctly heard what sounded like Rice Krispies in milk. Perplexed, I asked Google what was going on, and Google said, "leaf miners are eating the centers of your boxwood’s leaves". They were making quite a racket. They are either noisy eaters, or there were thousands of them. There was probably no time to lose, so I ignored it. 

A few weeks later I saw the damage to the leaves. They were wrinkling up and turning color. I split one leaf open, and inside were tiny orange maggots, from two to six in every leaf I checked. Now that I could see the little orange bastards, it pushed me into action. I asked google how to deal with them without resorting to pesticides. Google said, "you must resort to pesticides". Particularly, a systemic insecticide that would be taken up by the plant's roots and distributed to the leaves. I applied the systemic, but I was afraid I ignored it too long. They were probably stuffed and pupating and turning into adults. 

Two weeks later, my fears were confirmed. What looked like fat orange mosquitoes were flying in swarms around my boxwood, fornicating and laying eggs in the new leaves. The boxwood wouldn’t survive another generation of these Trump-colored vermin. But I was still loathe to use more insecticide. Hoover to the rescue. I took my vacuum cleaner out on the porch, and began vacuuming the mango scum, much to the dismay of my girlfriend who was awakened by the noise, and immediately questioned my sanity (not for the first or last time). To no avail, I explained my rationale about avoiding the use of insecticides that may harm beneficial insects. Verdict... I was a crazy person. I kept vacuuming. They just kept coming. After a while I went inside to take a nap. 

I woke to the sound of a vacuum cleaner. Yes, outside was my girlfriend vacuuming boxwood. We were both obsessed. This went on for nearly two weeks. The neighbors were too polite or too scared to mention our obsession, but I doubt the boxwood would have survived another season without the intervention, and they look well on their way to recovery. I have to admit though, it was a lot of effort for a few lousy boxwood.

These days I have a forty-minute commute to work, and I enjoy the progression of bloom through the season, of everything from landscape ornamentals to woodlots and farm fields. There is always something happening. There are some plants I would like to see less of, though.

In late May the purple, white and pink flowers of Hesperis matronalis, aka Dame's Rocket, bloom in abundance all up and down the roadsides and into fields and woodland edges. I love it, and I don't - it's invasive, having long ago escaped into the wild. It sows itself with abandon, soon forming vast colonies that crowd out and replace native plants. Related to Garlic Mustard, it spreads just as aggressively. If you like the look I would steer you to the tall phloxes, like P. paniculata or P. divaricata because we do not need any more of this plant. Don't get me started on Garlic Mustard, it's not even pretty.

But who says invasive plants *have* to be ugly? Here's another one that is a common sight in Michigan, Hemerocallis fulva, aka Ditch Lily. It's not a true lily, but a daylily, and not a neat clump-forming one, either. No, it spreads by rhizomes and forms large colonies filling the ditches on either side of roads all over the state. I like seeing the cheery orange flowers every summer but again, it's busily crowding out native plants. 'Kwanso' is a double form that is offered in the trade, it is not nearly as aggressive. 

One of the worst offenders is the notorious Lythrum salicaria, aka Purple Loosestrife. In spite of decades of trying to knock it back, by physical removal and the introduction of several species of beetle that eat it, it still occupies acres and acres of wetlands across the entire continent. None of our native animals or insects really need it for either food or shelter and I am personally over the obnoxious color of the flowers, too, because they just remind me of the futility of trying to put the Genie back into the bottle.

There was talk at one time that some of the named varieties were sterile or nearly so, but it turns out that they breed just fine with the wild ones. So even if you find it for sale, don't plant it. If you have it on your property, get rid of it. 

There are loads of invasive plants loose in Michigan, from Autumn Olive to Phragmites, Buckthorn to Spotted Knapweed, Multiflora Rose and Oriental bittersweet, to the honeysuckles - oh, boy, the honeysuckles... To all of them I say, hit the road! 

For more information about these and other invasives, check out these links!

• MSU Extension Field Guide to Invasive Plants - PDF
• Midwest Invasive Plant Network
• Michigan Invasive Species at Michigan.gov