The Hardy Everlasting

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The strawflower or everlasting (Xerochrysum bracteatum), on the left, is by far the most popular dried flower, but it’s an annual. More laidback gardeners might want instead to try the easier-to-grow, solidly perennial pearly everlasting (Anaphalis margaritacea), on the right. Source: & Pendragon29, Wikimedia Commons

Pretty much anyone who has made dried flower arrangements knows the strawflower or everlasting, also called golden everlasting, (Xerochrysum bracteatum), famous for its papery flowers that come in a wide range of colors. It gets the name strawflower from the straw-like texture of the bracts that make up the most visible part of its inflorescence and the name everlasting, because it dries so easily and can then be kept almost eternally. However, this Australian native is only perennial in the warmest of climates: hardiness zone 9 and above. Elsewhere, it can only be grown as an annual.

Fewer people know that there is also a perennial everlasting, a close relative (both are in the Gnaphalieae tribe of the Asteraceae or sunflower family), but one adapted to areas with much colder winters: pearly everlasting (Anaphalis margaritacea). Its flowers dry just as well and last just as long, but it’s a tough perennial that can be easily grown in almost all temperate-climate gardens.

It’s actually a very widespread species, native to the temperate regions of both Asia and North America. Introduced to Europe as a garden plant long ago, it quickly escaped and is now firmly established there too. It’s notably found in almost all continental US states except those of the Southeast, in all Canadian provinces and territories and it even extends well into Mexico in cooler mountainous areas. In other words, it’s pretty much ubiquitous in the wild.

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With its silvery leaves, pearly everlasting can make quite a show long before it even flowers. Here, you can see it with purple-leaved fringed loosestrife (Lysimachia ciliata ‘Firecracker’). Source:

Pearly everlasting is easy to recognize, both in the wild and in gardens. With its upright white stems and narrow, linear foliage, silver-green above and woolly white underneath, it creates an attractive effect even before it blooms. But it blooms abundantly too, with dense terminal clusters of small white inflorescences. The true flowers are tiny and golden yellow, grouped in the center of each inflorescence. What you’ll mostly notice are the white bracts that surround them, bracts with the same stiff, papery texture as those of the strawflower.


Pearly everlasting varies in height according to conditions … and perhaps also according to its genetics, because if it usually reaches between 2 and 3 feet (30 and 60 cm) in height, you’ll sometimes find colonies of almost 4 feet (1 m) tall and others, less than 8 inches (20 cm) in height.

As for diameter, it spreads by offsets produced on short stolons, so can grow to a considerable width. Expect a minimum diameter of 1 foot (30 cm) after two years, but it could cover 10 square feet (1 square meter) as a dense silvery groundcover after 4 or 5 years if you let it. Fortunately, even if it does spread quite quickly, it’s not difficult to control and comes right out of the ground when you give it a yank.

Easy to Grow

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Most people associate pearly everlasting with sun and dry soil, but it’s much more adaptable than that. Source: KENPEI, Wikimedia Commons

In nature, this plant grows mostly in dry, poor soils and intense sun. It’s often seen in fields and along roadways, but it is in fact much more adaptable than that in the garden, where it seems to be happy in soils of all kinds, even fairly rich ones, and will also tolerate partial shade. In fact, there are really only two environments where it won’t do well: soggy soils and full shade.

This is one perennial you may not have to buy, as it often shows up in gardens all on its own.

I wouldn’t say it’s a weed, because it’s so easy to pull out, plus it’s very pretty. However, it’s a rather—hmm, what word should I choose?—free-willed plant, giving to popping up where you least expect it. I like to think of it a gift from the goddess Flora, the Roman deity of horticulture.

Pearly everlasting colonies can last for decades and the plants bloom over a long period, from July to September. It’s also extremely hardy: to zone 2.

Lots of Flowers, But Where Are the Seeds?

Pearly everlasting is a dioecious plant: male and female flowers are produced on separate plants. It’s very popular with bees and butterflies, so they always ensure good pollination. As a result, if your plant is a female, you’ll have no trouble obtaining seed. If your plant is a male, though, it will produce no seeds at all.

Pearly everlasting grows readily from seed and sprouts with no special treatment. You can also propagate it by division and stem cuttings.


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Drying pearly everlasting. Source: Lavender Lori,

Traditionally, native peoples consumed leaves and young shoots of pearly everlasting in the spring and also used leaves medicinally in various ways, such as to treat burns. However, it is little used in modern herbalism.

Today, it’s mostly seen as an ornamental for use in mixed flower beds, xerophytic gardens and rock gardens, but also makes a great choice for a flower meadow or a rooftop garden.

Of course, it’s widely used in dried flower arrangements. For that purpose, harvest the stems before the yellow center is visible and hang them upside down until they dry. The flowers thus treated will last for many years.

Insects and Diseases


Attention: an ugly caterpillar can turn into a beautiful butterfly and indeed, this one will be a lovely painted lady one day. Source:

Pearly everlasting is rarely affected by disease and its dense, hairy covering seems to deter many harmful insects, although pollinators visit the flowers readily enough. It does have one common enemy, though: a spiky-backed black caterpillar with a yellow stripe.


Painted lady butterfly (Vanessa cardui). Source:

Before pulling out your arsenal of chemicals in an effort to eradicate the pest, it’s important to understand that this caterpillar is the larva of a very pretty butterfly, the painted lady, also called the cosmopolitan (Vanessa cardui). It’s a widely distributed butterfly—it’s found on all continents except Antarctica and South America!—that you probably want to see visiting your garden. However, the caterpillars do a fair amount of damage, chewing off the upper leaves and flower buds, leaving dark frass in their place. To protect your plant without depriving your environment of a future pretty butterfly, therefore, simply carry the caterpillar to a nearby field and release it on a wild pearly everlasting or other host plant, such as thistle or burdock, to let it continue its metamorphosis.


Although pearly everlasting is abundant in the wild and not unknown in gardens, it’s still mostly seen as a wildflower and little to no effort has gone into selection and hybridizing. As a result, there is only one cultivar I know of, ‘Neuschnee,’ commonly sold as ‘New Snow.’ Personally, I doubt that this seed-grown variety even really deserves a cultivar name, because it seems identical to the species. Some say that it is more compact, however, and claiming a height of 1 to 2 feet (30–60 cm). Zone 2.

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Triple-nerved pearly everlasting (Anaphalis triplinervis ‘Sommerschnee’). Source:

Another species of Anaphalis is sometimes cultivated: triple-nerved pearly everlasting (A. triplinervis). An alpine originally from the Himalayas, it’s interesting in rock gardens and borders and is perhaps a bit less of a spreader. It has about the same dimensions as the more common pearly everlasting, about 1 to 2 feet (30 to 60 cm) in height, but with broader leaves that have, as the name suggests, have three distinct veins. Its clusters of small grayish-white inflorescences are less dense than those of A. margaritacea. Zone 2.

A cultivar, A. triplinervis ‘Sommerschnee’ (‘Summer Snow’), is easier to find than the species itself and also more attractive because its inflorescences are pure white rather than grayish. It’s also more compact than the species: about 8 to 10 inches (15 to 20 cm) tall. Zone 2.

Pearly everlasting: easy to grow and ever so pretty, whether in the garden or in bouquets! And you may already be growing it without knowing what it was!20180815G Pendragon29, Wikimedia Commons .jpg


Don’t Panic When Your Onions Flop!


Onion leaves flop over to show they’re mature. Source:

Onions have a very dramatic way to show that their bulb is mature, one that may be alarming if you’re not forewarned. Their leaves suddenly flop over, lying on the ground, as if the plant had died. But the onion is not dead: this is only one step in the bulb’s maturation process.

Traditionally, when the leaves of about half the onions in a plot had collapsed, gardeners used a garden rake to knock the others over. This was believed to accelerate their maturation, although it’s far from sure this actually speeds things up.

At any rate, after a week or two after most of the onions have flopped and their leaves are really starting to do downhill, dig up the bulbs up and leave them lying exposed, roots and all, to the sun for a few days. (In case of rainy weather, lay them on a sheet of plastic in a garage or shed.) This cures them (hardens then off), causing the outer layer of dried leaves to thicken. That way, they’ll store better later. Since bruised or damaged bulbs won’t store well and will soon start to rot, don’t bother trying to cure them. Just use them fresh over the following few weeks.

The final step is to clean the bulbs lightly with a brush, bring them indoors and store them in a cool, dry place, like a root cellar. You’ll have homegrown onions all winter!


Is It True Chokecherries Are Poisonous?


Chokecherries are common throughout much of North America, but are they poisonous? Source:

Question: I would like your opinion on the edibility of chokecherries (Prunus virginiana). Is it true their berries are poisonous?

I’m a bit confused, as several websites mention that chokecherries are an excellent food for birds and some even say they can be used to make jams and syrups. But what really bowled me over was a page on the Canadian Poisonous Plants Information System. It states “Children have been poisoned and have died after ingesting large quantities of berries, which contain the seeds. All types of livestock can be poisoned by ingesting the plant material.”

I was appalled, as when I was young, we used to eat handfuls of chokecherries straight from the tree and we suffered no ill consequences. How is it possible that the berries can be both poisonous and non-poisonous?

Pierre Nadeau

Answer: I too used to eat the chokecherries as a boy, in spite of their astringent and none-too-sweet taste.

The secret is that it’s the pit (seed) that is toxic, not the fruit’s rather meager flesh. All cherries and other species of Prunus have poisonous pits. They contain amygdalin, a product the body converts into cyanide, a deadly poison, after consumption. However, people usually don’t eat cherry pits, not even those as small as the ones found in chokecherries. Instead, we spit them out, and thus suffer no risk of poisoning.

Cattle and other livestock eat chokecherries whole and can become poisoned if they swallow too many. Note that the text you found on the web specifies in the text that the children who died had swallowed the seeds.


The very popular Schubert chokecherry is grown as an ornamental. Source:

Chokecherry (Prunus virginiana) is the North American counterpart of Eurasian bird cherry (P. padus). Not only are both very similar in appearance, but they’re widespread on their respective continents and are widely used as ornamental trees, especially purple-leaved varieties, such as P. virginiana ‘Schubert’, P. virginiana ‘Canada Select’ and P. padus ‘Colorata’. Moreover, the indigenous peoples of both continents harvested and consumed the fruits, sometimes even the pits, which can be safely eaten after cooking, as that destroys the amygdalin they contain.

Note that that if a person accidentally swallows a few pits, they won’t be poisoned: a fairly large quantity needs to be eaten, as the dose makes the poison. On the other hand, you shouldn’t make the habit of swallowing them.

Curiously, the pits pass without difficulty through the digestive system of birds and, in the wild, over 70 species feed on them. That also appears to be true for deer, other cervids and bears, all of which eat chokecherries with impunity. On the other hand, sheep, cows, horses, etc. can be poisoned. Other mammals, such as chipmunks and mice, seem to know that the pits are toxic and eat the flesh without swallowing the pits. Note too that even the stems, bark and leaves of Prunus are toxic to many mammals.


Sweet almonds can be eaten raw, but bitter almonds are poisonous unless properly prepared. Source:

If the pits of all Prunus (cherry, plum, peach, etc.) are toxic to humans, how is it possible we can eat almonds, which are extracted from the pits of the almond fruit, another Prunus species (P. dulcis)? There are two answers to that question.

First, after thousands of years of selection, varieties have been developed that contain no amygdalin. They’re called sweet almonds and are the ones you find sold as almonds in grocery stories. But so-called bitter almonds (ones that contain amygdalin) can still be consumed if they are correctly heated beforehand and are, in fact, popular in many European and Asian diets. However, because of the risk to consumers, the sale of bitter almonds is prohibited in many countries.


You shouldn’t be eating apple pips either! Source:

Note too that the same situation applies to apples (Malus pumila): their seeds or pips are also toxic. That said, some people have the habit of sucking on and swallowing apple pips at least occasionally and yet they get away with it. That’s because, in most cases, apple seeds simply pass through our digestive system intact, so no poison is released. Chewing the seeds or piercing their coat is definitely not wise, as this will release the toxic elements. However, even then, few people are poisoned by apple seeds, as they are much less toxic than most Prunus pits. A healthy medium-sized adult can apparently eat over 200 ground-up pips without suffering serious poisoning.

The truth is many edible plants that have toxic parts or are toxic if they are not cooked beforehand. For more information on this subject, read Edible Plants With Poisonous Habits.

When harvesting plants from the wild or even our own vegetable gardens and orchards, it’s best to stick to consuming parts of plants we know to be safe, and even then, only after giving them the usually recommended preparation!20180813A

What’s This Weird Bug?

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Wasps infested with white muscadine. Source: Denise Lalonde

Question: I’m sending you a photo of some weird bugs I found on my astilbes. Can you identify them? Are they harmful?

Denise Lalonde

Answer: They are certainly weird, but they aren’t harmful … at least not to your plants.

What you’ve photographed are wasps killed by a fungal disease called white muscadine (Beauveria bassiana). This cosmopolitan disease is deadly to insects, but almost never touches warm-blooded animals, so there is no risk to humans or pets.


Spore cases of white muscadine, highly magnified. Source:

White muscadine spores overwinter in the soil. If an insect comes in contact with one of them, it sprouts on its body, then rapidly penetrates it, attacking the internal organs. The fungus eventually kills the insect, using it as a source of food, and a white-to-yellowish mold consisting of spore cases forms on the outside of the insect’s body. That’s what you saw.

Before it dies, however, the insect thus attacked spreads the spores through its movements, therefore helping to ensure the survival of the fungus. In the case of social insects like wasps, bees, ants and termites, the infected insect often transmits them to its fellow workers and this can annihilate the entire colony.

Sometimes the dying insects display a bizarre behavior. Instead of dropping to the ground to die out of sight, they settle out in the open, up on a plant. This means the disease spores will be more readily picked up and carried by the wind, increasing the spread of the disease. The theory is that the fungus actually takes control of the insect’s brain in its final hours, telling it where to go to die.

It sounds like something out of a horror film: the insect version of Invasion of the Body Snatchers!

Not all strains of white muscadine seem to have this effect, but there are hundreds (indeed, probably thousands!) of strains of this very common fungus and who knows what possibilities they hold!

Potentially Useful

White muscadine is certainly harmful to many insects and other arthropods, but is also proving itself useful to humans.

The potential of white muscadine in integrated pest management (IPM) has been known for a long time. Already in 1906, the possibility of using this disease to control harmful pests was brought up at the Congress of the French Association for the Advancement of Science. However, although progress has been made since, white muscadine is still not commonly used as a pesticide.

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Bed bug killed by white muscadine. Source: KDS444, Wikimedia Commons.

It does have some applications, though. For example, it’s used in the biological control of termites, banana weevils and red palm weevils and is being studied for the control of grasshoppers, bed bugs and malaria-carrying mosquitoes.

As mentioned, there are many strains of this disease. Some are generalists and attack a wide range of arthropods. They would probably not make good choices in IPM, because they attack both beneficial and harmful insects. Others, on the other hand, are quite host specific. Strain Bba5653, for example, attacks only the caterpillars of the diamondback moth (Plutella xylostella), harmful to cabbages and other crucifers, plus a few closely related moths. These are the strains scientists are looking the most seriously into.

White muscadine: a very odd fungus that could one day be among the most useful pesticides in the organic gardener’s arsenal. The next time you see a dead insect, take a closer look!20180812A Denise Lalonde

In Your Water Garden, A Few Fish Go a Long Way

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Fish are an attractive addition to water gardens, but don’t overdo it! Source: Arden, Wikimedia Commons

There is essentially no limit to the number of aquatic plants that can have a water garden (when you can no longer see the water because there are so many plants, it may be time to stop adding more!), but with fish, there sure is!

If there are too many fish, the oxygen level in the water will drop and your fish will suffer. Also, when there are too many fish, they produce more waste than the bacteria and plants can filter out and the water will become polluted and smelly.

To know how many fish your pond can hold, calculate about one goldfish per three to four square feet of water surface area and one koi for every 10 square feet of surface area. You need more space for koi, as they grow larger.

How to Control Horsetail

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Common horsetail (Equisetum arvense) is a weed found in gardens worldwide. Source: Stan Porse, Wikimedia Commons

If I had an easy solution for controlling common horsetail (Equisetum arvense), I’d be a rich man. But unfortunately this plant is very difficult to eradicate. And to make things worse, it will grow in just about any kind of soil, be it rich or poor, acid or alkaline, loam, clay or sand, wet or dry.

Do note that horsetail is less likely to become establishedin dry soils. You see, its windblown spores will only germinate under moist conditions. However, once the plant has settled in, it will readily tolerate dry conditions, although it will grow more slowly under dry conditions than in moist ones. Typically, the home gardener accidentally carries a section of rhizome from a moister setting to a drier one, sometimes in soil purchased from a nursery, leading to a new infestation.

In a garden watered regularly for the benefit of other plants, horsetail will be very much at ease and will spread rapidly.

Cultivating Makes Things Worse


Hoeing simply chops up rhizomes, making things worse. Source:

Cultivating or hoeing to control horsetail simply doesn’t work. The more you cultivate, the more it spreads, because cultivating slices the plant’s rhizomes into sections and each tiny section of cut rhizome left in the ground will produce a new plant.

Another reason that cultivating doesn’t work is that horsetails also produce tiny tubers, like little bulbs,on its rhizomes. Tubers tend to be produced deep in the ground, up to 5 feet (150 cm) down, well out of range of cultivation tools!

If you ever decide you do want to try to control horsetail by cultivating the soil, at least make sure you clean your tools before using them in another area, otherwise you risk spreading sections of rhizomes or tubers by accident. That’s why rototillers can be the horsetail’s best friends: not only does do they slice the rhizomes into numerous small pieces and spread them hither and yon, but some almost always stick to the blades, so when you move the apparatus to the next section of garden, you’re seeding horsetail at the same time. A rototiller really needs a good cleaning after each use!


Most non-selective chemical herbicides available to home gardeners (Roundup is the best known) are simply not effective against horsetail: it just doesn’t absorb them. Lawn herbicides (selective herbicides) are no better: they’re designed to kill broad-leaved weeds … and few weeds have narrower “leaves”* than horsetail!

*Actually, horsetails don’t have leaves at all. The whorls of narrow growths around the main stem are actually branches.

Some biological herbicides will kill horsetail foliage. Source:

One type of biological herbicide, though, is fairly efficient. Herbicides based on soap, vinegar and/or citric acid such as Ecoclear or Weed B Gone will effectively kill horsetail foliage, although not its rhizomes. You therefore have reapply them when the plant regenerates from underground, so they will require a bit of follow-up.

Note that using herbicides, even biological ones, in a flower or vegetable garden without also accidentally killing desirable plants nearby can be quite difficult.

No Sun, No Horsetail!


Black tarps won’t give your garden a very elegant appearance, but they will kill horsetail. Source:

You can, however, eliminate horsetail by preventing it from carrying out photosynthesis. In other words, by cutting off its only supply of energy: sunlight. If you keep its leaves from being exposed to the sun, the plant will quickly stop spreading and will eventually exhaust itself and die.

One method of cutting off the sunlight is to cover the infested section with a black tarp. (You can find this kind of tarp in any hardware store.) You have to leave it in place for 24 months to completely exhaust horsetail: it you remove it after only 12 months, there is usually a bit of regrowth. This method is only really practical when you’ve decided to start from scratch. It’s very difficult to use in an established garden with living plants (perennials, shrubs, etc.).

One method you can use in an established garden is to simply cut the sterile stems (green stems) to the ground whenever you see them. Unlike cultivating, which spreads the rhizomes, this causes them to weaken, as you’ll be preventing the plant from carrying out photosynthesis. Start early in the season and recut each time the plant regrows … and it will. By repeating each time a new shoot surfaces, the plant will eventually die. However, this method takes some effort: you may need to cut horsetail back 5 or 6 times the first year and some stalks may still come back in year 2 and will need to be cut back as well.

Or try dense planting with taller plants: large ferns, big perennials or thick shrubs, anything that will cut off the sun. Horsetail does best in full sun to partial shade. It weakens in deep shade. By creating dense shade, you’ll be ensuring that it will eventually disappear. It may take 2 or 3 years to get total control … but right from the start, taller plants will pretty much hide the horsetail from view anyway. Out of sight, out of mind!

The Dig and Sift Method

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It’s labor-intensive, but yes, you can sift soil to remove horsetail rhizomes. Source: Wikimedia Commons

In this technique, dig up all the horsetail plants in the sector, putting their rhizomes in the trash (the foliage can go into the compost). Now, empty the bed of soil to a depth to 1 foot (30 cm) and run it through a soil sifter (easily made from a wooden frame covered with ¼ inch [6.4 mm] wire mesh) before putting it back, removing all the rhizomes you find. Of course, some tubers may be left in the soil and manage to sprout, forming young plants. However, if you pull these out within a few weeks, they won’t have time to produce rhizomes and you’ll be able to stop a new colony from forming.

Obviously, this method is most practical for localized infestations. It will be hard to carry out on a large scale.

The Laidback Gardener Method

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Horsetail creating misty green swaths of growth. What’s not to like about that? Source:

I decided years ago I was no longer going to fight horsetail. I reasoned it was not stealing minerals from my plants (horsetail is not a heavy feeder) and, with its sparse foliage, it lets most of the sunlight through, so my plants still get their share of sun. And unlike dense growing weedy plants such as goutweed (Aegopodium podagraria), it rarely seems to crowd out desirable plants, just to blend in among them. To be honest, I find horsetail attractive. With its beautiful feathery foliage, it can give an attractive misty look to your landscape. If you can learn to accept horsetail as an ornamental, that will save you all the effort of trying to get rid of it.

Oddly enough, once I had decided to accept horsetail as a friend, it began to slowly disappear from my gardens. As they matured and became fuller, denser and shadier, there was no longer any room for horsetail.

Sometimes (and even often), tolerance is simply the easiest way to go … and it’s certainly the most laidback!20180810A

Garden Myth: Lime Can Control Horsetail

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Will lime really kill horsetail? Not unless you apply it in industrial quantities! Source:, &, montage:

Most garden myths have some element of truth. Such is the case of the one that insists you can control field horsetail (Equisetum arvense), also called common horsetail, a very invasive weed, by applying lime. You actually could eliminate horsetail with abundant applications of lime… but you won’t want to. And here’s why:

The proponents of the “lime controls horsetail” belief insist that field horsetail grows only in acidic soils. It therefore seems logical that, if you make the soil more alkaline, it ought to make conditions hostile enough that horsetail would die out.

But the first bit of information is wrong. Yes, horsetail does grow in acid soil, but it’s hardly exclusive to that soil type. It also thrives in neutral soils and does well even in moderately alkaline soils. (What it does like is moist soil, but that’s a different story.) It takes a very high pH (greater than 7.6) to seriously begin hampering the rampant growth of this common weed… but if your bring your garden soil to pH of 7.7 or above, you’ve essentially poisoned it: almost no garden plant you would think of growing will thrive in soil that is that alkaline! And I doubt if applying a “scorched earth policy” to your garden was what you had in mind!

Spread the Word

20150802BThis myth about horsetail is still widely shared by well-meaning gardeners, even horticultural professionals. Yet anyone who has ever tried to control horsetail with lime will tell you it’s simply a waste of time and money.

This is one garden myth that really deserves to die … so please don’t hesitate to share the real situation with your gardening friends.

But How Then Can You Get Rid of Horsetail?

Actually getting rid of horsetail is no easy task, but I’ll give a few suggestions in tomorrow’s blog, so … patience!