Sticky Leaves? Look Up!

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Have you noticed a sticky, shiny substance on the leaves of some of your houseplants? If so, look up, on the same plant or its neighbor. For the sticky stuff is probably honeydew, a substance produced by various sucking insects, including aphids, scale insects and mealybugs. Since the insect ingests enormous quantities of sugar-rich sap, more than it can digest, it must necessarily reject the excess sugary liquid and droplets of this honeydew fall onto leaves below.

Aphids. Photo: auxincc.wordpress.com

This problem can show up on houseplants any time during the year, but is most common in late winter and spring, as many insects, in diapause (near dormancy) in winter, rewaken and begin to proliferate massively with the return of longer days. Soon, there are not only a few drops of honeydew, but sticky liquid everywhere!

The insects responsible for this damage are found on the stems and leaves above, and can be quite unobtrusive, but now that you know where to look for them, you’ll find them without problem. Their honeydew has given them away!

What to Do?

What to do about such an infestation? The most logical thing is to (horror of horrors!) toss the plant and then closely monitor its neighbors for possible signs of future infestation.

You can also treat the plant, but…

Washing and rinsing a plant often rids it of insects temporarily, but 9 times out of 10, the pest will return. Ill.: Claire Tourigny, from the book Les 1500 trucs du jardinier paresseux.

Aphids, small plump insects, often green, are “relatively” easy to keep under control. If you wash the plant at the sink with soapy water and a sponge, cloth or soft brush, making sure you reach all its parts, and then rinse it with a strong stream of water, you will get rid of most of them, but if a single aphid remains, the infestation will start all over. 

Bummer!

Note that you need to use soap (insecticidal soap, black soap, Ivory soap, etc.) to treat insects, not dishwashing liquid. Most modern dishwashing liquids no longer contain soap and thus are not very effective against insects; plus they can damage soft plant parts.

Scale insects (left), mealybugs (right): both are prodigious producers of honeydew … and terribly hard to control. Photo: Gilles San Martin, Flickr & http://www.growweedeasy.com

As for mealybugs and scale insects (actually, close relatives), the same treatment, that is a thorough washing with soapy water followed by a strong jet rinse, is also possible, but even less effective. They often hide in places near but not on the plant, so you never get them all. Thus, they reappear, often months later and the infestation starts anew. And in the meantime, mealybugs and scale may have had time to spread to your other plants. 

Even the radical idea of cutting the infested plant to the ground, cleaning the stump with soapy water, then allowing it to grow back is rarely effective. I’ve done this more than once and at first it always seems to be working, then suddenly the scales or mealybugs are back. I just tossed a plant I’d cut back no fewer than three times, yet was never able to truly rid it of scale insects.


There you go! Examine your houseplants occasionally and if you discover sticky, shiny leaves, you’ll know what to do!

Save A Tree: Say No to Topping!

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Who hasn’t seen a tree pruned drastically, with all the branches cut back, often to the same length? This is called topping or heading … and it’s an incredibly bad idea. In my neighborhood, unscrupulous tree pruning companies leave notices in my mailbox every year offering to top my trees and I regularly see homeowners who have been taken in by the scam. Yet topping trees is always harmful to the tree it’s being applied to. In fact, many topped trees will actually die from the massacre.

Homeowners are promised topping will reduce the tree’s height, decrease the shade it produces, eliminate weak branches and improve the tree’s overall health. And they pay plenty to get exactly the opposite.

Poor pruning results in stubs that never heal over ((compartmentalize), letting rot and insects infect the tree. Photo: http://www.gardening-guy.com

Topping reduces all the branches to about the same length. They are cut with no thought to their structure rather than carefully at a point where the injury can “compartmentalize” (heal over) adequately. This creates a huge number of stubs: branch ends that die back rather than healing. These open wounds allow rot and insects to penetrate the tree and, over time, both can extend downwards through the tree and weaken its structure … if indeed they don’t out and out kill the tree.

A forest of suckers (waterspouts) will appear, none leading healthy branches. Photo: http://www.statesmanjournal.com

When a tree is severely pruned (that is, if it survives the onslaught), it rapidly grows back, producing numerous new branches called suckers or watersprouts that grow from the base of the stubs. As a result, any promised reduction in height or shade is temporary. And the suckers are far more numerous than the original branches, creating denser shade than ever.

And that’s not all!

Suckers are only weakly attached to the tree and as they lengthen, they begin to snap off under their own weight. As a result, once a tree has been topped a first time, it becomes necessary, for safety reasons, to top again every 3 to 4 years. So ever more money goes into maintaining a tree that probably needed no maintenance to begin with.

Unless the tree dies, of course, and many will die from this severe attack on their structure and their health. Trees seldom die quickly, though, but few homeowners think to trace the tree’s decline back to the tree pruning service that they hired 10 or 15 years earlier. And removing a dead tree costs money too!

An Easy Solution

Don’t top trees. Photo: http://www.arborday.org

The solution is easy: simply don’t top trees! There is no situation where topping is recommended: it is poor arboriculture, period. There are many legitimate reasons a tree may need pruning: dead or damaged branches that have to be removed for safety reasons, badly placed branches that need shortening, a crown that needs thinning, etc. An arborist can do all the above and much more, but will do so selectively, branch by branch, cutting in just the right places. A certified arborist will not accept to top a tree; he or she can be barred from the profession for doing so. Anyone who does offer to top one of your trees is simply a charlatan!

For more information on the hazards of tree topping, visitPlant Amnesty, an organization dedicated to ending the senseless torture and mutilation of trees by bad pruning.

Article originally published on March 18, 2015.

Sweet Pepper or Chili Pepper? Different Taste, Same Plant

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Sweet pepper and chili pepper: your taste buds tell you instantly they are two different things. One has a mild taste and is eaten as a vegetable, the other has a burning taste and is used as a condiment and in hot sauces. One is big and the other is small. They’re two different plants, right?

Well, no, not from a botanical point of view. Both share the same Latin name: Capsicum annuum.There may or not be a few added genes from two other species, C. frutescens and C. chinense, especially in the case of chili peppers … but many botanists believe both are just variants of C. annuum. And even if most sweet peppers in the Western world have large cubic fruits (bell peppers) and most chili peppers, small conical ones, in fact, either can have fruits large or small, rounded, elongated, conical, cubic or completely irregular. Both too can come in a wide range of colors.

Ill.: graph.datanet.co

The real difference between chili and sweet peppers is therefore found entirely in the taste: chili peppers contain capsaicin, a pungent component that burns not only the tongue, but even the fingers (you have to wear latex gloves when harvesting very hot peppers). Their burning taste is so overwhelming few people notice their underlying flavors. Sweet peppers, on the other hand, contains no capsaicin or very, very little of it, so richer, sweeter flavors come to the forefront. To measure the effect of capsaicin, Scoville units are used. Sweet peppers usually contain 0 SHU (Scoville heat units), banana peppers a bit more (100 to 500 SHU) while Habanero peppers, said to taste “very hot,” from 100,000 to 350,000 SHU …and pure capsaicin contains an incredible 16 million SHU!

‘Carolina Reaper’. Photo: Dale Thurber, Wikimedia Commons

Currently, ‘Carolina Reaper’ holds the world record for the hottest chili pepper: up to 2.2 million SHU. Eating just one fruit of ‘Carolina Reaper’ has sent some consumers to the hospital!

Here is a video of two Americans who dare try eating a ‘Carolina Reaper’ pepper. There are many other videos showing such feats on the Internet, so if you’re the slightest bit sadistic: enjoy!

Growing Your Own Peppers

Young pepper plants. Photo: growhotpeppers.com

Peppers are tropical plants and therefore only in very mild climates could you consider sowing them directly outdoors. Elsewhere the growing season simply isn’t long enough or warm enough. Most of us will have to start ours indoors, normally about 9 weeks before the last frost date. You can sow peppers in plastic pots or cell packs, but since the roots are a bit fragile, peat pots are preferable.

In the garden, peppers need a spot in full sun. Only plant them out after the soil has thoroughly warmed up: above 60˚F (16˚C). In regions where summers remain cool, peppers may have to be grown inside some sort of greenhouse structure: a sheet of clear plastic stapled over a wooden frame will do.

Hot peppers are hottest when grown in hot climates. Photo: ya-webdesign.com

It’s not for nothing that countries with hot climates (India, notably) have the reputation for producing the hottest peppers: although the intensity of a pepper is mostly controlled by genetics, the environment also plays a role. Therefore, peppers grown at extreme daytime temperatures of up to 90˚F (35˚C), that often suffer from lack of water and that are planted in rather poor soil will give the very hottest peppers. These are the peppers to test for inclusion in the Guinness Book of World Records!

Well-watered peppers grown in cooler climates and enjoying a nitrogen-rich fertilizer may seem a tad bland to the taste buds of the hot pepper aficionado, but even in cooler climates, you can boost the intensity of hot peppers growing them in a sheltered spot and in containers—preferably dark colored containers—to maximize the heat they receive. Also, avoid nitrogen-rich fertilizers and let the soil dry out slightly between waterings.

That said, genetics still win out over all and a truly hot pepper, like ‘Carolina Reaper’, will still bring fire to your throat, tears to your eyes and probably an ambulance to your door, no matter where it is grown.

Pepper Seeds

Most seed companies offer at least a modest selection of sweet and chili peppers, but you’ll probably have to buy world record class pepper seed, like ’Carolina Reaper’, from a specialist. Here are two: Puckerbutt Pepper Company and Pepper Joe.

Belch No More With Burpless Cucumbers

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You’ve probably noticed that cucumbers (Cucumis sativus) sometimes make you burp. This is due to the presence of cucurbitacin in the fruit, one of the bitterest substances known to humans. Cucurbitacin is present in wild cucumbers where it serves to protect the plant against predation, but at a reduced rate in cultivated cucumbers. However, in most garden-grown cucumbers, the amount of cucurbitacin will increase when the plant is suffering from heat and drought, giving the fruit a bitter and unpleasant taste … and also causing belching in sensitive individuals.

To help avoid this problem, always mulch the base of the plant to keep its roots cooler and be sure to water it so it never suffers from drought. Or you can plant burpless cucumbers. They have a genetic mutation that reduces or eliminates cucurbitacin in the fruit, making them less likely to cause belching, although the leaves still produce it.

Some entire classes of cucumber are burpless. English, Japanese, Lebanese and Persian cucumbers are all easily digested, as are Armenian cucumbers, also called yard-long cucumbers, which are actually a different species (C. melo flexuosus). However, there are plenty of good ol’ garden-variety slicing cucumbers that won’t make you burp … if you grow them with care.

You Choose!

‘Garden Sweet Burpless Hybrid’ is a typical burpless cucumber. Photo: http://www.gardensalive.com

In this season when it’s time to buy vegetable seeds for the summer garden, here are some burpless varieties to look for.

‘Beit Alpha’
‘Big Burpless’
‘Burpless Beauty’
‘Burpless Bush’
‘Burpless Hybrid’
‘Burpless No. 26’ or  ‘Burpless #26’
‘Burpless Tasty Green’
‘Chelsea Prize’
‘Chinese Snake’
‘Cool Breeze’
‘County Fair’
‘Early Spring Burpless’
‘English Telegraph’
‘Garden Sweet Burpless Hybrid’
‘Green Knight’
‘Manny’
‘Marketmore 80’
‘Muncher’
‘Orient Express’
‘Palace King’
‘Perseus’
‘Spring Burpless’
‘Suyo Long’
‘Sweet Burpless’
‘Sweet Slice’
‘Sweet Success’
‘Sweeter Yet’
‘Summer Dance’
‘Tanja’
‘Tasty Green’
‘Tendergreen’ (‘Tendergreen Burpless’)
‘Thunder’
‘Wautoma’

The Apple Tree That Turned Into a Crabapple Tree

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Question: I had to cut down two apple trees a few years ago and new stems came up from the base. I let one of those stems grow back and after several years, it produced flowers and fruits. To my astonishment, though, it only gave crabapples barely 1 inch (2.5 cm) in diameter, while the original tree had big apples. Is this the juvenile form? Will my tree produce full-size fruits one day?

A. Jolin

Answer:  No. And here’s why:

The apple trees we buy are always grafted, that is, their stem was inserted onto another variety, called a rootstock. So, essentially, you bought two trees in one. 

The rootstock is inevitably what you’d call a crabapple*, one with small fruit. So, when you cut the original apple tree back, what grew from the base of its trunk was not the apple you wanted, but the rootstock, genetically different from your large-fruited apple tree. When it bloomed, it therefore produced fruits that were normal for it: small apples.

*Crabapples and apples are the same species, Malus pumila. Its humans who decided ones with small fruits are called crabapples and those with large ones, apples.

Juvenile apple trees don’t fruit at all. That’s why it took a few years after your apple tree grew back before it began to flower and produce fruit again. Once an apple is mature enough to bear fruit, it will immediately start producing fruit of the size and appearance of those of a fully adult tree: there are no intermediary stages.

Moreover, you would have experienced the same situation with almost any fruit tree that was cut back to the ground: cherry, plum, pear, etc. They are inevitably produced by grafting and if, unfortunately, the upper part dies, what grows back from the base will be the rootstock variety bearing fruit of lesser interest.

Grafting to the Rescue

You can turn a crabapple tree with uninteresting fruit into the apple tree of your choice through grafting. Photo: growingfruit.org

You can, of course, dig out your unexpected crabapple tree and replace it with an apple tree of any variety you want, but you could also graft branches of a desirable apple tree onto your crabapple tree, giving it back its original role, that of rootstock. You could even graft several varieties of apple tree onto the same rootstock and thus pick McIntoshes, Lobos and Cortlands from just one tree.

The best time for grafting is in the spring, when the buds begin to swell. 


All this goes to prove that you can indeed teach an old apple tree new tricks!

Luther Burbank, the Plant Wizard

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Although Luther Burbank may not be well known to modern gardeners, he was famous a century ago, known the world over as the Plant Wizard. Born March 7, 1849 in Lancaster, Massachusetts, U.S., he was probably the most famous horticulturist who ever lived. 

He introduced over 800 new plants over a 55-year career, including fruits, flowers, grains, grasses, trees and vegetables. His remarkable horticultural creations stunned the world and he was avidly supported by such luminaries as Thomas Edison and Andrew Carnegie. At the same time, scientists decried his total lack of scientific rigor, as he took few notes and his explanations of his hybridization programs were more than vague.

His Life

Luther Burbank had no horticultural training and, indeed, no more than a high school education. The thirteenth of eighteen children, he was always interested in gardening. Upon his father’s death when he was only 18 years old, he used his inheritance to buy a farm in Lunenburg, Massachusetts.

There, in 1873, he developed and launched his first and probably most successful hybrid: the ‘Burbank’ potato (Solanum tuberosum ‘Burbank’).

The ‘Russet Burbank’ potato. Look familiar? It’s your typical Idaho potato! Photo: http://www.specialtyproduce.com

The new potato was a seedling of the cultivar ‘Early Rose’. He discovered that it was not only productive, with large, white-fleshed tubers, but resistant to late blight (Phytophthora infestans), the disease that caused the Irish potato famine of 1845 to 1849. He hoped his new potato would prevent the recurrence of such a tragedy. ‘Burbank’ would latter give birth, by spontaneous mutation, to a russet-colored clone called the ‘Russet Burbank’. It remains one of the most widely grown potatoes in the world. Even today, most McDonald’s French fries are made from ‘Russet Burbank’ potatoes.

Burbank sold the rights to the ‘Burbank’ potato for $150 and used the money to move to Santa Rosa, California in 1875. There he set up an experimental farm with greenhouses and a nursery. Inspired by Charles Darwin’s book The Variation of Animals and Plants under Domestication, he began cross-pollinating, often trying outlandish crosses that had no chance of success or else, produced real duds, like his attempt to cross a petunia with a tobacco plant. This resulted in weak-growing, floppy plants with neither useful leaves or attractive flowers.

But then, there were also great successes: more about them later.

He would marry twice, but had no children. He was often in dire straits financially: he may have been a plant wizard, but he certainly couldn’t balance a budget! Eventually a group of friends formed the Luther Burbank Society to manage his affairs.

He died of heart failure on April 11, 1926 at the age of 77. The famous horticulturist was buried in an unmarked grave at the Luther Burbank Home and Gardens in Santa Rosa, California. This historical site is still open to the public daily, free of charge.

Some of his Accomplishments

Shasta Daisy

Shasta daisy ((Leucanthemum ×superbum)). Photo: http://www.amazon.com

Burbank set out to to develop a long-flowering, large-flowered daisy from the common oxeye daisy (Leucanthemum vulgare) and crossed it with several other species, gradually getting better and better plants. It took him nearly 20 years, though, to finally create the Shasta daisy (L. × superbum) we know today, named for California’s snow-covered Mount Shasta. It remains one of the most widely grown perennials in the world. One of his Shasta daisies, ‘Alaska’, is still popular today.

Plums

The ‘Santa Rosa’ Japanese plum (P. salicina) is a Burbank hybrid. Photo: http://www.bowerandbranch.com

Burbank was very interested in fruits and considered plums his life’s work. He especially worked with Japanese plum (P. salicina) and other Asiatic species, at the time just being introduced in California, and he began crossing them with other species, notably the European plum (P. domestica). He would eventually introduce many plums to the market, including at least three, ‘Santa Rosa’, ‘Burbank’ and ‘Wickson’, that are still grown. 

He likewise dabbled in peaches, nectarines and cherries, producing among others the ‘July Elba’ peach and the ‘Flaming Gold’ nectarine, both still grown today.

Stoneless Plum

Stoneless plum. Photo: Cooking Up a Story, http://www.youtube.com

Starting with a French plum hybrid (Prunus domestica) called ‘Sans Noyau’, which naturally had a stone about half the size of other plums, Burbank worked for years to develop a plum with no stone at all, one you could simply pop into your mouth and eat. Unfortunately, this gave a fruit much lighter than regular plums and prune growers were at the time paid by the pound, so were not interested in a stone-free plum. It was long thought lost, but has recently been rediscovered and, who knows, may yet make its way to a farmer’s market near you!

Plumcot

Burbank plumcot (Prunus salicina × Prunus armeniaca ‘Burbank’). Photo: http://www.treesofantiquity.com

This is a primary cross ( ½ plum,  ½ apricot) between a Japanese plum (P. salicina) and an apricot (P. armenica) and gave a fruit with the flesh of a plum and the taste of an apricot. When Burbank first introduced the plumcot in the early 1900s (he’d eventually release 11 different varieties), he was called a lier by other plant breeders, who considered this cross impossible. Eventually, though, he was proved right, as others were able to repeat the cross, and indeed, plum/apricot crosses would be further refined by others into what we know today as a pluot (¾ plum, ¼ apricot). And yes, you can find pluots in certain farmer’s markets! 

White Blackberry

‘Iceberg’ blackberry (Rubus × ‘Iceberg’). Photo: http://www.homedepot.com

Burbank was very proud of this creation, although it never caught on commercially. Starting from a wild pale-coloured blackberry found in New Jersey called ‘Crystal White’, it took him over 65,000 unsuccessful crosses to finally produce a variety with pure white fruits, ‘Iceberg’, often sold as Snowbank., which he launched in 1894. This cultivar is still around and every now and then it will catch the attention of a grower who usually promotes it as something totally new. But now you know different!

Spineless Cactus

Spineless cactus (Opuntia cv). Photo: Picssr, Flickr

Burbank introduced more that 60 varieties of spineless cacti between 1907 and 1925. His idea was that the spineless cactus would transform deserts into places where cattle could graze and, thanks to their edible fruits and pads, could also feed the starving masses. Most of his spineless cactus are hybrids of the Indian fig (Opuntia ficus-indica) and the Mexican prickly pear (O. tuna). None reached any commercial success during Burbank’s lifetime, but some are now widely grown, notably in Mexico. Their individual cultivar names are long lost, but they’re often globally referred to as ‘Burbank Spineless’.

Other Introductions

Here are just a few of Burbank’s other creations, most, sadly, now long gone:

Vegetables

  • ‘Burbank Admiral’ pea (1908)
  • ‘Crimson Winter’ rhubarb (1900)
  • ‘New Burbank Early’ tomato (1915)
  • ‘Rainbow’ corn (1911)

Fruit

  • ‘Black Giant’ cherry (1911)
  • ‘Robusta’ strawberry (1920)
  • ‘Sebastopol’ thornless blackberry (1920)
  • ‘Van Deman’ quince (1893)

Flowers

‘Burbank Crimson’ California poppy (Eschscholzia californica). Ill.: Mihran Kevork, California State Library.
  • ‘Burbank Crimson’ California poppy (1904)
  • ‘Burbank’ rose (1899)
  • ‘Burbank’s Giant Hybrid’ amaryllis (1906)
  • ‘Lemon Giant’ calla (1893)
  • ‘Mayflower’ verbena (1901)
  • ‘Molten Fire’ amaranthus (1922)
  • ‘Surprise’ daylily (1917)

Trees

  • ‘Paradox’ walnut (1893)

Not Forgotten

Luther Burbank’s birthday is still celebrated every March 7th in California as Arbor Day. In fact, it is now feted as Arbor week (March 7-14). But wherever you live, let’s all give a toast to this fantastic plantsman on this, his birthday!

WorryFree Barberries … and Why They May Never Be Sold in Canada

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For years now, I’ve been following the development of sterile barberries, that is, varieties of Japanese barberry (Berberis thunbergii) that produce no fertile seed. 

Why is this important? Because this popular shrub has escaped from culture in many parts of the Northeastern United States and become invasive, taking over vast tracts of fields and open forest where it forms much of the undergrowth. This is thanks to the seeds contained in its berries that are ingested by birds and spread everywhere in their droppings. 

Here, Japanese barberry has entirely taken over the forest floor, leaving little room for native plants. Photo: Leslie_J. Mehrhoff, University of Connecticut, Bugwood.org

I’ve actually visited such a forest in a nature reserve in New England and was amazed at how abundant Japanese barberry was. It was quite obvious that it was indeed taking over and likely replacing native plants, including food plants for many native animals.

The situation is so serious that Japanese barberries, although long a staple in landscaping, have been banned from sale in Massachusetts and other states are considering following suit.

Sterile Barberries to the Rescue

Crimson Cutie barberry. Photo: SynRG, LLC

Dr. Mark Brand of the University of Connecticut has been working on developing sterile barberries for over 15 years now. It’s just not a question of finding a sterile plant, but of testing it, not in only in a greenhouse, but in the field, for both ornamental value and total sterility. Any barberry worth releasing as sterile simply must neverproduce fertile seeds. 

Barberry fruits with fertile seeds (left) and aborted seeds (right). The latter are sterile and will produce no offspring. Photo: Dr. Mark Brand, Dept. of Plant Science and Landscape Architecture, University of Connecticut

But Dr. Brand has indeed found totally sterile clones; in fact, many of them. They produce berries just like any other barberry, but the seed inside aborts at an early stage and so can never germinate.

And the best are now being released in the WorryFree™ series. So far, the series is composed of Crimson Cutie™ (‘UCONNBTCP4N’), a dwarf mounding variety with deep purple leaves, already available in many areas, and Lemon Glow™ ‘UCONNBTB048’, likewise a dwarf mounding variety with brilliant chartreuse-yellow leaves, just coming out now. Others are under study.

WorryFree barberries can be used in the landscape without fear their seedlings will escape into the wild. They are such outstanding garden plants—attractive and easy to grow—that they have already been adopted by the Hand Picked For You Plants® plant certification program, designed to recommend only the very best garden plants to home gardeners. And even states have become involved: Crimson Cutie has been approved for sale in New York State by the Department of Environmental Conservation and other environmental associations are considering such an approval.

But Never in Canada

WorryFree Lemon Glow barberry. Photo: SynRG, LLC

It is, however, unlikely that WorryFree barberries will ever be commercially available in Canada. 

Wheat rust, carried by the common barberry (Berbris vulgaris), but not the Japanese barberry (Berbris thunbergii), is a serious disease of wheat. Photo: http://www.ars.usda.gov

That’s because, in 1966, Agriculture Canada banned the sale and distribution of barberries. This ban was due to a wheat disease, black stem wheat rust (Puccinia graminis), that was known to use certain barberries as an alternate host. In other words, the disease necessarily spends part of its life cycle on a barberry plant before moving to nearby fields of wheat. For that reason, all barberries were banned to protect Canada’s wheat crop.

In the years that followed the ban, it was discovered that not all barberries are hosts of wheat rust. In fact, the main culprit is the common barberry (B. vulgaris). The Japanese barberry (B. thunbergii) does not carry the disease. Bans on Japanese barberry were therefore lifted elsewhere in the world, but remain in effect in Canada.

However, after 35 years of pressure from plant nurseries, in 2001 Agriculture Canada finally relented and allowed the sale of 11 cultivars of Japanese barberry that were individually tested and found to be rust-free. They quickly became popular garden shrubs and indeed are already staples in Canadian landscaping.

Barberries ‘Helmond Pillar’ and Sunjoy Gold Pillar™ are not available in Canada and probably never will be. Photo: springmeadownursery.com

However, although new and interesting disease-free barberry cultivars (think of the beautiful pillar-shaped varieties ‘Helmond Pillar’, with purple leaves, and Sunjoy Gold Pillar™ (‘Maria’), with golden ones) have since been released, no other barberry has ever been approved for sale in Canada, nor, from what I hear, does Agriculture Canada ever intend to change things. Given the reluctance with which Agriculture Canada has responded in the past to matters concerning ornamental plants, obviously very much the least of its concerns, I don’t expect wider barberry approval will occur in Canada within my lifetime.

Admittedly, the problem may be less serious in Canada than in the United States, as, according to my personal observation, Japanese barberries simply don’t seem to self-sow in cold climates. Thus, although the adult shrubs may thrive in very cold conditions (up to zone 3), there appear to be few seedlings below zone 6 and certainly none in zone 4 where I live. Thus, many Canadian gardeners might not need to be too concerned for now (although with global warming looming…!). Still, southern British Columbia, southern Ontario and milder parts of Nova Scotia are prime candidates for Japanese barberry invasion and I know that the Ontario Invasive Plant Council is very concerned about the species.

So, as the rest of North America switches to sterile barberries for environmental reasons, stodgy old, misguided regulations will likely prevent Canada from following suit. 

Environmental damage due to government inaction? Gee whiz, there’s really nothing new under the sun!