Hole’s has released two books this spring: the latest in the What Grows Here series, What Grows Here? Indoors, and Maggie Clayton’s Create an Impression: Landscaping for Curb Appeal.

In What Grows Here? Indoors, Jim, in his usual friendly and informative manner, discusses real life indoor plant problems and suggests plant choices for every kind of location in private homes, businesses, offices, schools, hospitals and nursing homes.

Create an Impression is a must-have resource of 23 professionally designed, easy-to-create front yard landscape plans presented in stages. Maggie teaches you how to use commonly available plants to create to landscape a new property or revive and polish a tired one.

Firsst published February 22, 2007

There was a time in the not-so-distant past when gardeners had to blend their own potting soils. Today, premixed bags are the norm, and I would say that the vast majority of gardeners would loathe the idea of ever turning back the clock and having to become potting soil ‘chefs.’ Most of us simply don’t want the hassle, mess and uncertainty that comes with making a quality potting soil.

But in gardening, like in any good hobby, there exists a small but adventurous group who like nothing more than to tinker—to tweak soils to create a custom blend that might allow them to squeeze that extra tomato from their plants or to grow that huge dahlia flower that becomes the talk of the neighbourhood. Soil tinkerers, as I like to call them, have an innate and irrepressible desire to start their soils from scratch or to modify existing ones.

One size fits one
Although I’m all for simplicity, there are two compelling reasons to develop your own soil blend—the first reason being that there are too many horrendous potting soils in the marketplace. Some so-called professional potting soils are little more than extraordinarily poor quality peat moss dotted with a bit of perlite. The second reason is that the one-size-fits-all concept for potting soil just doesn’t work for every permutation and combination of plant varieties and back-yard environments. For example, a shade-loving plant in a pot in a damp corner of the yard may require a coarse soil (one with a high volume of perlite), whereas a pot that sits in the blazing sun on a south-west facing deck would benefit from a soil with greater water-holding capacity (one that contains vermiculite).

So if you believe you have the heart and soul of a tinkerer and you want to try to customize your potting soil, then give it a shot—but just remember the cardinal rule: always start with the highest quality ingredients. You can’t cajole a poor quality potting soil into yielding quality flowers any more than you can create an award-winning cake from old eggs and spoiled flour.

The basics
The basic potting soil ingredients to tinker with are coarse, blonde peat moss (never dark decomposed peat moss), coarse perlite (fine types don’t allow for good drainage), vermiculite (horticultural-grade holds water best; never use insulation grade) and lime (horticultural), which is essential for balancing pH.

A couple of ingredients that aren’t essential but are often the tinkerer’s ‘magic’ ingredients are good old-fashioned garden soil and compost. Garden soil has gone the way of the dodo bird in profession horticulture because of its variability, but it can provide a cheap source of nutrients and some extra water-holding capacity if it isn’t too sandy. It’s important to remember, however, that all garden soils should be pasteurized before being added to any potting mixture. Pasteurization involves heating the soil to a temperature between 60 C and 80 C for a couple of hours to kill most of the disease, insect and weed pests that might be lurking about. If pasteurizing garden soil seems too ambitious, use compost—it rarely needs to be pasteurized unless it wasn’t composted properly.

The exact proportions of basic ingredients to add to potting soils are jealously guarded by some tweakers, but a good starting point for novices is a mix with about 60% coarse peat moss, 20% coarse perlite and a 20% combination of compost or pasteurized garden soil and vermiculite. The last ingredient you want to add is lime. Its main job is to neutralize the acidic peat moss. The amount you add will depend on the volume of peat moss you have. For example, a typical large bag of peat moss (170 L) requires approximately 750 g of horticultural lime.

It’s interesting to note that although I have talked to a lot of gardeners who are extremely proud of their beautiful plants, I have also spoken to a great many gardeners who are just as proud of their potting soil. It just goes to show that there’s more than one way to enjoy gardening. Perhaps to potting soil tinkerers, nothing would make them happier than to turn their gardening worlds upside down.

Hits & Misses: Grass happy & love lost
Question of the Week: Is mushroom compost good for my garden?
The Business: North American Farmers Direct Marketing Association
Science & Technology: Smoke on the water

With the late February days growing longer, one can almost believe that spring is a possibility! The days are warming and the snow is retreating, which means it’s time to think about watering some of your evergreens, in particular—the cedars. In our corner of the world, it’s not the cold that kills our cedars; it’s the drought. Drought on the prairies is often thought of as a summer phenomena, but winter drought is very real and affects cedars when they are subjected to long periods of frozen soil in combination with sunny, windy days and above freezing temperatures. Because cedars are evergreen, they continually lose moisture through their foliage. In the winter, they are unable to replace that moisture because the water in the soil is frozen. At times of the year when the weather is mild but the ground is frozen, cedar foliage can become irrevocably dehydrated and ‘burned.’ To keep your cedars lush and green, water as soon as the snow is gone and the air is above freezing temperature. Waiting until April is too late for drought-stressed cedars.

Winter browning

Hits & Misses
Hits: Grass Happy
I have never seen as many varieties of grasses in our greenhouses as I have this year. Grasses have exploded in popularity, and it’s not hard to figure out why. Not only are they drought and cold tolerant, but they are also bug-free, by and large. One in particular that caught my attention was a new variety of Panicum virgatum called ‘Panicum Ruby Ribbons.’ Its deep wine-red foliage is simply outstanding. With so many new species and varieties with interesting seed heads and leaf colours, they are sure to find their way into many gardens this year—including my own.

Misses: Love Lost
The Valentine’s love wasn’t exactly red hot with passion across many parts of North America this year. From what I’ve been hearing throughout the industry, the tepid Valentine’s flower sales were due to the exceptionally cold and snowy weather. As a result, we have one of the most stunning crops of azaleas ever just sitting and languishing in our greenhouses, waiting for their princes to arrive. I guess it’s not meant to be…Valentine’s 2007 seems destined to be known as the year of unrequited love.

Question of the Week
Is mushroom compost good for my garden?
Soil quality is the first thing to focus on in the garden when the snow finally melts away and the warm weather returns. And one question I get asked regarding this subject is whether or not mushroom compost is good for the garden. Well, the answer is yes and no. In the long term, mushroom compost will increase the organic matter in the soil and provide an excellent root environment for plants. But mushroom compost is also a ‘hot’ product in that it has a high concentration of salts that can burn plant roots. Because the burn potential exists, apply no more than a 2-cm-thick layer of mushroom compost and blend it thoroughly into the garden soil. It’s also never a good idea to sow seeds directly into pure mushroom compost—germination would be severely inhibited unless the seed varieties were incredibly salt tolerant.

The Business
Family Farms in a Competitive Marketplace
I was at the North American Farmers Direct Marketing Association conference in Calgary last week. This organization is comprised of farmers who offer everything from fresh fruits and vegetables to agro-tourism. While there, I had the opportunity to learn about some of the trends that are holding for 2007. Corn mazes, for example, are exploding in popularity, offering children and adults alike great educational opportunities and entertainment. The big corporations will always attract a sizable chunk of our dollars, but its nice to know that family farms are reinventing themselves and carving out a niche in this competitive marketplace.

Science & Technology
Smoke on the Water
In the latest issue of Hortscience, I came across information about researchers investigating the effects of ‘smoke water’ on plant growth. Smoke water is exactly what it sounds like—smoke captured in water—and it’s being sprayed onto the seeds and leaves of plants to stimulate their growth. The researchers found that the compound butenolide, which is found in certain types of smoke, stimulates seed germination and increases growth in some species of plants. For example, both okra and tomato seedlings treated with smoke water were significantly larger than the non-treated seedlings were. The smoke was collected from a species of plant called Themeda triandra (kangaroo grass). Basically, an aqueous smoke extract was prepared by bubbling the smoke of smoldering kangaroo grass leaves through water. But to you tobacco smokers out there, don’t think you can justify your habit by saying that you’re puffing is for the greater good of your plants…tobacco hasn’t been short listed for testing!

first published February 8, 2007

With citrus crops threatened by California frosts and Florida tornadoes, the time might be ripe to think about homegrown lemons and oranges.

Of course, I’m not envisioning vast prairie fields chalk-a-block with rows of citrus trees—our winter weather is just a tad too cold for that—but what about our homes? Perhaps they could act as surrogates for the orchards of the citrus states.

Now before I get you jumping up and down dreaming of homegrown lemons for homemade lemon meringue pie, let me just say that most people have homes ill-suited for citrus trees.

A sunshine state
The overriding factor that makes or breaks citrus growing in our homes is sunlight. Without at least four hours of direct sunlight striking the leaves of citrus trees for a good chunk of the year, citrus trees will (at best) fail to fruit and (at worst) lose all of their leaves, resembling the denuded deciduous ash and poplar of winter. Therefore, the critical first step before selecting a citrus tree for your home is to see if you have a suitable sunlit spot to place it. If you think you have that perfect spot that receives at least four hours of direct sunlight per day, then check to see how much space you have. Many citrus trees available for interior cultivation are dwarf species that won’t get too big, but keep in mind that this doesn’t mean they are windowsill plants, so know what size of citrus plant you can accommodate so that you can dedicate enough space for future growth.

If you have what you believe is an ideal spot for a citrus tree, then it’s time to think about picking citrus varieties that are suitable for interior-scapes. One of the best citrus varieties for the home is called ‘Meyer.’ It is a dwarf lemon/orange cross that has a high tolerance for cool temperatures relative to other citrus varieties and it flowers freely, producing a fair number of fruit if the sunlight levels are adequate. Even with free-flowering and self-pollinating varieties like Meyer, winter light levels are often too low to get fruit to set. Each tree shoot acts autonomously, sensing the ambient light levels and then decides whether there is enough light to initiate fruit development. Being that a sunny day in January provides only about a fifth the amount of sunlight energy that a sunny day in July provides, fruit is a rarity during the winter months. In fact, with light levels being lower during winter months, the only thing you can really expect from your citrus trees this time of the year is leaf shed.

A common cultural requirement of citrus trees is that they require well-drained soils. They abhor sitting in water-logged soils for any length of time and respond by dropping leaves. The soil fertilization strategy is not that difficult to follow. Choose a high nitrogen fertilizer, like 30-10-10, and apply it once a month during the sunny time of year, which is from April until about August.

Good-sized citrus trees aren’t cheap; no, let me rephrase that. Citrus trees are cheap if you compare their prices to furniture. It never ceases to amaze me how many of us don’t bat an eye at a coffee table that costs several hundred dollars but, at the same time, recoil in horror if a citrus tree is the same price. Well, I think it is high time that we rethink our attitudes toward some plants. They are living works of art and I have heard them, quite appropriately, described as ‘living furniture’—a label that really elevates them to their proper place in our homes.

So if you have that perfect spot for a citrus tree, I say nudge that ‘dead’ coffee table over just a bit and put the term living back into living room.

Hits & Misses: ‘Red Sensation’ cordyline & lame brains
Question of the Week: Do I need to use a rooting compound on my cuttings?
The Business: Plant pirates
Science & Technology: The ‘yuck’ factor

We are always trying to find that perfect temperature balance for our perennials, which is an elusive goal at the best of times, but especially in the coldframes. With the least bit of provocation in the form of heat, some perennials, like Adonis, will emerge from dormancy and flower long before our customers are ready to buy them. Controlling the temperatures in the perennial coldframes is a particular challenge in February when the days are often cold but the sun intensity is quite strong. Although ‘warm coldframes’ sound like an oxymoron, they are all too real. Take it from me, it’s tough to pull sub-zero air into the coldframes and keep the plants cool without freezing them solid. Even with all the advances in technology, the best climate control systems still require a fair bit of human intervention to keep the plants in good shape.

Hits & Misses
Hits: ‘Red Sensation’—Take Two!
The ‘Red Sensation’ cordyline is looking great this year. Last year was the first year we grew Red Sensation, and although its red foliage looked good, one year’s worth of growth wasn’t quite enough to produce plants big enough to truly stand out in the centre of pots or planters. Fortunately, overwintering them has made all the difference and with the extra year under their belts, the cordyline have developed extra growth and a more attractive cascading habit that will make them an ideal—and substantial!—addition to any container.

Misses: Lame Brains
Our new computer-controlled misting system was driving me crazy last week. We had 17,000 geranium cuttings arrive and because they were unrooted, we had to mist them for eight seconds every half hour—round-the-clock—for the first few days. Unfortunately, just as our cuttings arrived, our computer decided that it would be the appropriate time to behave erratically. Having tried (and failed) time and again to correct the problem, and not wanting to lose 17,000 cuttings, I had no choice but to do a nighttime vigil to make sure that the cuttings would get enough mist to survive the night and to buy myself enough time to solve the problem. At 3 a.m. that winter night, the reason for the computer’s erratic behavior became clear. A magnet had been placed on the bottom of the controller and had temporarily scrambled the computer’s brain. Once I removed the magnet, it wasn’t one but rather two brains that miraculously started functioning properly.

Question of the Week
Do I need to use a rooting compound on my cuttings?
A lot of people are thinking about starting cuttings in their homes and are a little confused about whether or not to use rooting compounds. Rooting compounds contain rooting hormones that mimic those found naturally in plants. Without the right type and balance of hormones in cuttings, root initiation and growth would not occur and the cuttings would very quickly whither and die. While many cuttings are capable of initiating roots all on their own, synthetic rooting compounds can boost root growth on tough-to-root cuttings. Rooting compounds are designated by the titles 1, 2 or 3. The 1 has the lowest concentration of a rooting hormone called IBA, 2 has an intermediate concentration and 3 has the highest concentration. Whether or not you need a rooting hormone for your cuttings really depends on what you are trying to root. Some cuttings like New Guinea impatiens do just fine without them, but for some of the hardwood cuttings, rooting hormones dramatically increase the odds of success.

The Business:
Deterring Plant Pirates
Plant breeders spend a lot of time and money developing new varieties, so it makes sense that they would want to protect their creations from plant pirates who like to swoop in and illegally propagate plants. I like what one of our suppliers out of Holland has done to combat the problem. His name is Jan van den Top, and he creates plant varieties at a company called Darwin PlantSpotters. For each of his plants he issues a tag complete with a certificate of authenticity and a plant serial number. Jan’s even gone as far as to include a photo of himself on the tags. Although illegal propagation is tough to eradicate, at least some breeders are attempting to find a partial solution. And who knows—perhaps having Jan van den Top staring back at people from each and every tag will be enough of a deterrent to plant pirates.

Science & Technology:
The ‘Yuk’ Factor
There is a certain ‘yuk’ factor involved when apple flesh turns brown shortly after being bitten into. Researchers with Agriculture and Agri-Food Canada in Summerland, B.C. are investigating how to mitigate the browning of apple fruit so that cut apples can be marketed in grocery stores. Breeding apples that don’t turn brown quite so readily is one area of research that is being explored, but the researchers have also discovered that certain phosphorus fertilizers can reduce the amount of cut-edge browning that apples get. Stay tuned!—freshly cut apples could be the next cool fruit item in our grocery stores.

First published February 8, 2007

When I think about Valentine’s Day and all of the romantic prose that’s been written about the enamouring qualities of flowers, I can imagine Shakespeare holding an unfurled rose in one hand while writing about its intoxicating scent with the other. But if Shakespeare were alive today, I can’t help but wonder if he would he feel that same inspiration after inhaling the scent of one of our modern-day rose varieties. I doth think not.

Times have changed, and with Valentine’s Day fast approaching, many rose lovers will once again be left wondering if Shakespeare was stretching the truth about his beloved roses. Maybe it’s just me, but I think the sad reality of our modern roses is that, while there is a vast array of varieties with large flowers that are vibrant with rich colour, the rise of visually beautiful varieties has come at the expense of fragrant ones. But how did we get to this point in the ‘evolution’ of roses? And where did the fragrance go?

‘Fragrant Cloud’

Well, it doesn’t appear that there is some grand conspiracy by plant breeders to eliminate fragrance. Rather, it seems the disappearance of fragrance in roses has more to do with the wishes of the people who love buying bouquets of flowers.

At first glance, it seems rather counterintuitive that consumers could deserve the blame for the disappearance of rose fragrances. After all, who doesn’t want a bouquet that is both beautiful and fragrant? But plant breeders know that, in the hierarchy of human senses, when it comes to flowers, satiating our eyes takes precedence over satiating our noses. Like it or not, vibrantly coloured flowers push our ‘buy’ buttons more often than fragrant flowers do, so plant breeding, inevitably, chases the dollar and panders to our optic senses.

Have your rose and smell it, too?
Although plant breeders know what pays the bills, I don’t doubt they would love it if every variety could have both beauty and fragrance. But it seems that from a rose’s perspective there is too high a price to be paid by being both beautiful and fragrant. A plant’s fragrance is the result of a combination of volatile oils that are released by its flower to attract pollinating insects. But oil production comes at a substantial energy cost to plants—energy that could have been utilized for a multitude of other plant needs, such as generation of more food-producing leaves or more defense chemicals to fight plant diseases. Some researchers have even speculated that the susceptibility of some rose varieties to the fungal disease powdery mildew can be attributed, in part, to plant energy being diverted to oil production.

All, however, is not lost in the fragrance department. While rose breeders are aware of the demand for bold and beautiful-looking flowers, they also know that there are rose lovers who would still love nothing more than to have the flower fragrance paradox solved; and the sooner the better. In the meantime, there are a still a few varieties that will satisfy scent-starved noses. The fragrance winner at our greenhouse is the hybrid tea rose aptly named Fragrant Cloud (not hardy here unless it is thoroughly winter protected). Other favourites are Barbra Streisand, Octoberfest and Peace.

So if you’re thinking about giving a spectacular bunch of roses to someone you love this Valentine’s Day, consider what it is about roses that he or she loves. Because if you’re one of those people who looks forward to receiving a Valentine’s Day offering of sweet-smelling roses, getting a bouquet that isn’t fragrant could add a touch of bitter to the sweet.

When I was flipping through a newspaper on the weekend, I came across an article on urinals shaped like large, ceramic flowers. No, I’m not kidding. The company that makes these urinals offers a variety of flower types, including a spectacular Jack-in-the-pulpit featured in the article. Quite frankly, this work of art looked far too precious to be used for such a basic human function. But I suppose it’s also fair to say that all flowers need a little fertilizer from time to time.

Clark Sorensen’s Jack-in-the-Pulpit; part of the “Nature’s Call” Collection from www.urinal.net

Hits & Misses
Hits: Specimen Plants
We are in the midst of seeding our ‘specimen’ plants for the spring. Specimen plants are the mature versions of the transplants that we sell as annuals in our greenhouses. For example, if you were buying a pack of morning glories, a large, mature morning glory in full flower would usually be displayed nearby to show you that, yes, the plants you are buying will indeed look as glorious as the specimen plant. It’s amazing how customers respond to these mature specimens. We’ve tried this approach with many different plants, and even run-of-the-mill plants like broccoli really capture the interest of our customers. I used to assume that everyone has seen a mature broccoli plant growing, but the reality is that as our society becomes more urbanized, many people have only seen broccoli in its harvested form displayed on store shelves.

Misses: An Almost Miss
With Valentine’s Day just around the corner, we are trying to fine tune the blooming of our azaleas, and that means juggling temperatures to get them to be in full bloom at just the right time. We have some azaleas trained into heart shapes on trellises that we had to pull out of the warm greenhouses and stick into our cold frames to cool their passions, so to speak. Removing azaleas from a relatively warm 18˚C greenhouse and putting them into a rather cool 14˚C greenhouse causes a dramatic slowing of flower unfurling, and if my calculations are correct, a week at 14˚C should get the azaleas right on track for the weekend prior to Valentine’s Day. Whew, talk about romantic pressure.

Question of the Week
How do I acidify tap water before I give it to my houseplants?
I had a question last week from a customer who was wondering how to acidify his tap water prior to watering his houseplants. Several different chemicals will acidify water, but the first question I asked this particular customer was why would he want to acidify his water in the first place? His response was that he had some plants that were acid loving and he thought that, logically, the water should be acidified to grow them properly. In the greenhouse industry, growers pay special attention to their water supply because it can have a substantial impact on their crops, and there is a huge variation in water quality from one part of the continent to the other. But, by and large, Edmonton and surrounding areas have water that is well suited to growing a vast array of plant species. The bottom line is that I wouldn’t worry about trying to manipulate water pH. I’d be more concerned about matching the right soil mix to the specific plants that you are growing.

Business
Some Like it Hot
Companion planting is a term that is used to describe species of plants that prefer to grow in close proximity to one another. In our greenhouses, we have plant compatibility issues as well, but in our situation, we don’t worry about how plants feel about each other. Instead, we must group species and varieties of plants together into environments for which they have a common preference. This seemingly simple task requires a huge amount of juggling to get just right. For example, two plant varieties may like a similar temperature range but have different preferences for light intensity. Others may share the same temperature and light preferences, but one may like a drier environment. For example, while caladiums and pansies share a love of the same light conditions, the two species hate each other’s preferred temperature environments. We seldom achieve perfect harmony but, then again, what relationship doesn’t have challenges from time to time!

Science & Technology
Increasing Your Plant Consumption
The new Canada Food guide has just come out and once again it’s put a greater emphasis on increasing our consumption of plants. If the guide has inspired you to grow more edible plants, that’s great; but if you think that you don’t have the space or the time to grow vegetables or fruit, think again. Many gardeners with limited space and time grow their entire vegetable ‘garden’ in pots. It is easy to do, and you can have a continuous supply of fresh produce all season long. If you are a novice to container gardening, start with one large pot and grow some leafy vegetables. Mesclun is a mixture of salad vegetables that are ideal for containers and easy to grow.

Spidermites are often the bane of indoor gardeners. Jim gives a few quick tips on how to deal with these tenacious pests.
Quicktime
WMV

First published February 1, 2007

Messy, time consuming, intimidating, tough to schedule—these were some of the first words and phrases blurted out by a few people who I informally surveyed on the topic of starting seeds in homes…or were we talking about my kids?

Starting seeds at home can be frustrating, which is why, for most gardeners, it makes a lot of sense to leave the difficult seedling phase to the professionals. But there still remains one compelling reason for starting your own plants from seeds: some of the best plants aren’t available as transplants from greenhouses but are available as seed from garden centres. So as you thumb through all the seed catalogues that arrive this time of the year and marvel at the new varieties, keep in mind that if don’t take a stab at starting them at home, they may never see the light of day in your garden.

Quick Tips
Before you sow your first seed indoors, here is a short list of tips that will hopefully reduce the fear (and possible loathing) of your foray into the tricky world of seed germination.

Not all seedling mixtures are created equal, so always start with a high quality mixture, like Premier’s Ultimate Seeding Mix. Poor quality seed often gets the blame when seedlings fail to emerge, but nine times out of ten, it’s poor soil quality that’s to blame. Quality mixtures cost only pennies more per tray than bad mixtures, so don’t be penny wise and dollar foolish.

Plant in a clean environment. There is no point in going to the trouble of buying clean seedling mixture and then subjecting it to a dirty work area. When you think of the ideal seedling environment, an image of a hospital should spring to mind—not Old MacDonald’s farm. Success with seedlings requires that everything that comes in contact with them is disease free. That means clean soil, clean trays, clean tools and clean water. Even failing to wash your hands can have a deleterious affect on your seedlings.

Seedling soil should be watered fairly heavily prior to sowing but never after. The only additional water to add after sowing is a mist to replace the water that is lost. Seeds need oxygen to germinate as much as they need water, but the often irresistible temptation is to soak seed flats when the seeds fail to emerge quickly. Be patient. Over watering will drown seeds or wash them to the sides of the flats.

Seedlings hate to be crowded, so give them plenty of space. Far too often, seeds are sown too thickly and they quickly become a jumbled mass of soft, stretched seedlings that are impossible to separate without becoming damaged. Always err on the side of providing what seems like luxurious space.

Seedlings also need warm soil for successful germination. The air temperature in a room may feel warm to you, but it’s probably not ideal for newly sown seeds. Seedling soils are damp for obvious reasons, and have a net cooling effect on the soil as the water absorbs heat to evaporate. To create the ideal environment, always place seedling flats on a heated surface and keep the soil temperatures between 22 and 24˚C. The only thing to remember is that although seeds love warm soil, seedlings don’t. Once they begin to poke out of the soil, move the flats to a bright, cool (16˚C) spot. Don’t hesitate even for a day—seedlings must be inspected twice a day (morning and evening) for emergence. Failing to move the seedlings to a cooler zone is where most people go wrong. Bright and cool environments yield stocky, tough plants, whereas warm environments with poor light will yield stretched, weak seedlings that won’t adapt well to the outdoors.

Hopefully, you are beginning to at least warm to the idea of thinking about starting seeds at home. The process might seem a little overwhelming, but it really is worth trying. You won’t have perfect results every time, but most gardeners take consolation in there always being next year. I guess when it comes to starting seeds, having a long winter and a short memory isn’t such a bad thing.

Hits & Misses: Sweet primula & short supplied tumbler tomatoes
Question of the Week: How do I get rid of aphids on my hibiscus?
The Business: Detoxifying damaging rays
Science & Technology: Remediation of waste & collection of cadmium

There have been a lot of arborists out and about pruning the street trees in Edmonton lately. Although January may seem like an odd time to prune, there are a couple of good reasons for giving them a trim during the coldest time of the year—the first being that the tree crews need to play catch-up. With the successive years of drought we’ve experienced, tree crews are using the winter months to remove dead branches and, unfortunately, dead trees. The other reason is that many of our street trees are majestic American Elms, which are prone to Dutch Elm disease. This disease is carried by elm bark beetles that are active from March until early October. Elm bark beetles are attracted to fresh branch wounds, so by pruning during the late fall and winter, there is no chance of bark beetle activity. Fortunately, no beetles harbouring Dutch Elm disease have shown up in Edmonton—but why tempt fate?

Hits & Misses:
Hits: Sweet primula
The primula are in glorious bloom right now in the greenhouses. Nothing alludes to the promise of spring like a greenhouse filled with waves of primula flowers. Their beauty is matched only by their wonderful fragrance. If you are planning on getting a few primula for your home, keep in mind that they will retain their beauty and fragrance longest if they are placed in a bright but cool room.

Misses: Tumbling Toward Crop Failure
Tumbler tomatoes are one of our best selling varieties, but it appears they could be in short supply this year! Apparently, there has been a crop failure with the propagators of the tumbler variety, so although there will still be a reasonable supply of them this year, my advice would be to shop early.

Question of the Week
How do I get rid of aphids on my hibiscus?
I was talking recently to a customer who told me a story about some gardening advice my mother had given her a few years ago. Apparently, the woman had a hibiscus that was loaded with aphids, and she had tried every type of insecticide available to eradicate these tough-to-kill pests. Just as she hit her aphid-tolerance limit and was preparing to throw out the plant, Mom told her that rather than throwing out the hibiscus, she should simply strip every leaf off the plant. By doing so, she would eliminate the aphids and the hibiscus could recover. Now, I must admit that I would never advise someone to take as radical an approach as that to combat a bug problem, but when I asked this customer how the denuded hibiscus did with the tough love approach, she said the hibiscus very quickly returned to its former glory—completely free of aphids. It’s nice to know Mom’s sage (albeit drastic) advice lives on.

The Business:
Damaging Rays
With intense summer sun and high temperatures, greenhouses can be a pretty hostile environments during the summer. When I was walking through our cutting greenhouse this past week, I could see how the sun had cracked some wood and caused a few plastic valves and nozzles to deteriorate—and after just one season. What I found fascinating at that moment was how plants could take these very same destructive solar rays and ‘detoxify’ them, so to speak, taming the sun’s energy and storing it in the form of proteins and sugars. Too bad our skin can’t do the same thing.

Science & Technology:
Remediation of waste & collection of cadmium
Phytoextraction is not the kind of word that rolls off of the tongue, but it is a word that we are likely to become more familiar with in the future. Industrial waste is a reality of our modern existence, and remediation of that waste is often very challenging. Phytoextraction involves using specific plants to absorb heavy metals like cadmium from contaminated soils. What makes it particularly efficient is that the plants can then be harvested and disposed of properly, and the metals can also be either disposed of properly or recycled. Researchers with the ARS (Agricultural Research Service) in the U.S. have been working with a plant called alpine pennycress (Thlaspi caerulescens), which is particularly good at absorbing heavy metals through its roots and storing them in its leaves and stems. Alpine pennycress can concentrate up to 8000 parts per million of cadmium in its leaves. The beauty of phytoextraction is that, according to the ARS, it costs about $250–$1000 per acre a year, whereas removal and replacement of soil costs about $1,000,000 per acre. No need to crunch the numbers here.
By the way, we have our own pennycress plant here in Alberta. It’s called Thalaspi arvense—otherwise known as stinkweed.