Garden Myth: Tomato Leaves Are Poisonous

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Plant Tomato Leaf Vegetable Tomato Growing Leaf

Common knowledge insists tomato leaves are poisonous, but is it true? Photo: Max Pixel

Well, this is kind of a mix of myth and truth, because tomato leaves can be seen as toxic or nontoxic, depending on your point of view.

Yes, they are toxic because they do contain toxic alkaloids, including tomatine and solanine.

But they’re not toxic enough to poison you unless you consume them in very large quantities. (An adult would have to consume about 1 pound/450 g of tomato leaves to become sick.) Also, the leaves’ unpleasant smell is usually enough to discourage most people from munching on them.

Since they can be safely eaten under most circumstances, some chefs recommend adding one or two tomato leaves to tomato recipes to enhance their “tomato flavor” which can otherwise be diluted by cooking.

Green Fruits Too

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Immature (green) tomatoes do contain toxic alkaloids, but not enough to be harmful. Photo: Hans, pixabay

Still not sure you should try them? Remember that many people who would never think of eating tomato leaves use green tomatoes (that is, immature ones, not the “green tomatoes” that remain green when ripe) in recipes (fried green tomatoes, tomato chutney, tomato relish, etc.), yet immature tomatoes are as rich in tomatine and solanine as tomato leaves. In fact, the level of those alkaloids only diminishes to almost nothing when the fruit reaches its final coloration.

Destroyed by Cooking?

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Cooking won’t significantly reduce alkaloid levels in tomato leaves. Photo: Ildar Sagdejev, Wikimedia Commons

A few sources I looked at suggested that tomatine and solanine are destroyed by cooking, which would make the leaves safe to eat, but in fact, they are very stable compounds that don’t break down to any great degree when they are heated. On the other hand, they do dissolve in water, so if for some reason you boiled tomato leaves, then drained away the cooking water, that would be a way of reducing any toxicity.

Can Toxins Be Good for You?

Like many toxins, alkaloids like tomatine and solanine can also be, at the appropriate dose, good for your health. Tomatine, for example, has antibiotic and antifungal properties and it would appear it can even help prevent cancer … but many studies still need to be done before offering tomato leaf pills as a cure-all!

Leaves as Insecticide?

While tomato leaves when used in moderation may be non-toxic to humans, they do appear to be toxic to some insects, especially aphids. In fact, some gardeners produce an insecticidal spray by soaking tomato leaves overnight in water. But what is toxic to insects is not always for humans, so that really proves nothing.

Conclusion

There appears to be no risk in consuming tomato leaves in moderate quantities, so it’s best to conclude that the idea that tomato leaves are toxic is a myth. Just don’t overdo it!Plant Tomato Leaf Vegetable Tomato Growing Leaf

The Fascinating History of Orange Cauliflower

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20170814A Heather Kennedy, Flickr

Orange cauliflower. Photo: Heather Kennedy, Flickr

You’ve probably seen one in the supermarket or a public market, although you may have hesitated to try it: bright orange cauliflower (Brassica oleracea botrytis). And no, it was not tinted with vegetable dye nor is it a GMO: orange is its true color. And its history is quite fascinating.

A Discovery That Led to Plenty of Research!

In 1970, a market gardener from Holland Marsh, Ontario, noticed, among his rows of white cauliflowers, a plant that was unlike any other, with a small but bright orange head. Rather than destroy it, he allowed it to bloom and produce seeds … and some of these seeds ended up at the New York State Agricultural Station in Geneva, New York, part of Cornell University.

That’s where researcher Dr. Michael H. Dickson, a crucifer specialist, began experimenting with this odd cauliflower. He crossed and recrossed this unique variety with standard size white cauliflowers to improve both its dimensions and taste while enhancing its orange coloration.

At the same, he studied orange cauliflower and discovered that its odd coloration was due to a mutation that increased the quantity of beta carotene, a precursor of vitamin A, that it produced. (It’s also beta carotene that gives carrots their orange coloration.) So, with 25% more beta carotene than a white cauliflower and just as many minerals and other vitamins (calcium, magnesium, iron and vitamins B, C, E and K, among others), orange cauliflower is also better for your health.

Dr. Dickson’s team introduced orange cauliflower in 1981 … without much success. The public didn’t seem ready to accept such an unusually colored vegetable. Still, a few growers did pick it up and, over time, orange cauliflower has gradually entered the mainstream, at least to the point where it’s occasionally seen in regular supermarkets and farmers’ markets.

The Situation Today

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‘Sunset’ cauliflower. Photo: West Coast Seeds

Today, there are several orange cauliflower cultivars, the best known probably being ‘Cheddar’, ‘Orange Burst’ and ‘Orange Bouquet’. But despite a name like ‘Cheddar’, which seems to evoke a cheesy taste, orange cauliflowers have about the same taste as a white cauliflower and can be used in exactly the same recipes, although some say they have a creamier texture.

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The color range of modern cauliflower. Photo: SuperFoodsRx

Can you grow orange cauliflower yourself? Of course! They are no more complicated to grow from seed than white cauliflower. Moreover, you can also add to your cauliflower repertoire purple cauliflower (rich in anthocyanin, an antioxidant) and green cauliflower. Seeds of colorful cauliflower are available from many seed companies.

So, give yourself a challenge next summer: plant colored cauliflower in your vegetable garden … and surprise your family with more colorful—and healthier!—meals.20170814A Heather Kennedy, Flickr

Garden Myth: Make Cuttings at a 45° Angle

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20170813A.jpgSometimes horticultural myths aren’t exactly wrong, it’s just that they add an unneeded complication to what should be simple. Such is the case for the belief that you should always make stem cuttings (and also leaf cuttings) at a 45° angle. This is often said to stimulate rooting or to allow the stem or leaf to better absorb water.

Many gardeners firmly believe this, largely because they were always told to do it. In fact, this information does indeed appear in many of the most popular gardening books and on many websites, but it’s simply an old belief that has no particular foundation.

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Avoid very acute angles, as they can lead to rot.

The reality is that you can take cuttings at almost any obtuse angle: 45°, 60°, 90°, etc.

There is, however, a limit to cutting at too narrow an angle. Very acute angles, say 25°, will leave the very tip of the cutting only a cell or two thick and therefore very fragile. This could easily lead to rot setting in … rot that could spread to the rest of the cutting and that’s not something you want.

Personally, I usually take my cuttings at about a 90° angle simply because … it’s faster that way. When you try to make high-precision cuts, you waste too much time!

To learn more about how to take and root cuttings, read Rooting Cuttings Step by Step.

Cuttings in a Water Bottle

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Cuttings of Hypoestes in my water bottle during a recent trip. Photo: laidbackgardener.wordpress.com

You’re traveling and someone offers you a few cuttings to take home? Rather than having to look for a plastic bag and a piece of damp paper towel to wrap around the base of the stem to keep it moist (the traditional way of transporting cuttings, but rather difficult to do when you’re in a garden setting), think about another resource that you probably already have on hand: your water bottle!

If it’s full or nearly full, pour out a bit of water so that only the end of the cut will remain soaking in it: a depth of 3 cm to 5 cm will suffice. Now, if it’s not already done, remove the cutting from the plant (you can simply pinch it between your thumb and forefinger if it’s a softwood cutting, but a penknife can be handy for a woody one). True enough, a clean cut is best … but don’t worry about that at this point: you can always give the cutting a more even cut when you get home.

Next, slip the cutting into the bottle. You may have to compress or squash the foliage a bit to get it into a bottle with a narrow neck, but that won’t hurt the cutting in the long run. Now just screw the cap on the water bottle and you’re ready to travel … although you may have to buy another bottle of water for your own needs!

Obviously, a wide-necked water bottle (as seen in the photo) is more convenient, as it will be easier to extract the cutting when you are get home. However, even a narrow-necked bottle, such as a commercial water bottle, will suffice if necessary, as you can always cut open it with scissors or a sharp knife once you’re at home. And if you’ve never taken a cutting before, read Rooting Cuttings Step by Step.

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Root the cuttings inside a plastic bag to conserve humidity. 

Do root such cuttings in a humid environment, such as by covering them with a clear plastic bag, as they’ll have become used to 100% humidity inside your water bottle.

How Long?

How long can a cutting can remain sealed inside bottle—and probably also without much light!—before it starts to rot? Normally at least two weeks, probably longer.

Have a nice trip… and bring back lots of new plants!

Pinch Off Those Coleus Flowers

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Remove coleus flowers if you want the plants to keep their shape. Photo: Cole Shatto, Wikimedia Commons

Today’s coleuses (Plectranthus scutellarioides, formerly Solenostemon scutellarioides or Coleus blumei) is very different from the coleuses that used to be available.

I can well remember the coleuses of my childhood, with beautifully colored foliage, true enough, but they were all upright plants that you put at the back of the border because they soon lost their lower leaves and began to look ungainly. There was never a sign of branching… that is, unless you induced it by pinching. Every time you pinched the tip of a branch, it produced two branches, so the idea was to pinch early and often, which gave you a nice, full, rounded plant you could put on display in the front of the border or in a container.

Plus, you had to pinch off the flower stalks that inevitably appeared at the stem tips. The insignificant narrow spikes of bluish flowers added nothing to the plant’s appearance and the plants would start to go into decline after they bloomed, losing their lower leaves and looking very awkward.

The result was that there was a lot of pinching going on!

Coleus Without Pinching

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Modern coleus, like ‘Henna’, need no pinching to look good. Photo: Claudette Gallant, Publicdomainpictures.net

Flash forward to today. Most modern coleuses branch all on their own, naturally forming dense, shrubby plants. This is not due to some magical hormonal treatment or to GMO manipulation. Over the years, hybridizers have simply been crossing the top-perfoming coleuses together and keeping the best of the brood for further breeding. Genes for self-branching and also delayed flowering were brought to the fore and became the norm. This is the same process that changed ordinary garden weeds into the vegetables that we eat today, that is, keeping seeds of the best specimens to sow the next year until you get a plant that suits your needs.

Thus, you no longer have to pinch or prune most modern coleuses: they grow perfectly without your help. It’s the ideal situation for the laidback gardener! Except that…

Some Varieties Still Bloom Prematurely

Some varieties are not as “advanced” as others and begin to bloom early, in August or even July. This is especiallyly the case for varieties that are normally grown from seed rather than cuttings, such as the Wizard and Giant Exhibition strains. It may therefore be necessary to pinch (prune) these varieties at least once, as soon as you see the beginning of a flower spike.

20170811C.jpgPinching off coleus flowers is a snap: just squeeze the spike between the thumb and forefinger until it comes free. Or cut it off with pruning shears. It only takes a second.

Still, that’s an extra effort I prefer to avoid.

Which Varieties to Save?

One can, of course, treat coleuses like annuals and buy new ones each spring, but not being in the “money is no object” category, I bring in cuttings of my favorite varieties in the fall. I root them and grow them over the winter under lights or on a sunny windowsill, then in spring, take cuttings of my cuttings to fill my summer garden. And one criteria that is important to me and helps determine which to keep is lack of bloom: I automatically drop from my list any coleus that even shows a sign of a flower stalk during the summer months. I prefer the total laidbackedness of varieties that are not inclined to bloom prematurely*.

*These coleus will bloom nevertheless (all coleuses will), but only when they have a long growing season, for example, if they’re grow year round in a greenhouse.

Long live carefree coleus … and long live laidback gardening!20170811A Cole Shatto WC

Trees: Wanted, Dead or Alive!

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Although dying, this tree is still playing a useful role in its environment. Photo: Philip Harding, geograph.org.uk

Trees are essential parts of our landscape. We cherish them for the beauty they give to our gardens and cities and the way they filter and clean the air we breathe and bring the temperature down a few degrees in the heat of the summer. Just seeing them has been shown to make people feel better and relax, lowering heart rates and reducing stress.

And trees are long-term investments. Some can live 1,000 years or more … but very few do.

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City trees are often short-lived. Photo: Kgbo, Wikimedia Commons

City trees, which have to battle pollution, poor soil, poor drainage, insufficient soil volume, salt buildup, branches ripped off by tall trucks, slamming car doors and vandalism, to mention just a few inhibiting factors, have an average lifespan of only about 15 years according to one study, although another allows them 25 years.

The outlook for trees grown in home gardens and parks is much better: more or less 100 years for maples and beeches and 75 years for most oaks and spruces. Even naturally short-lived species, like paper birch and mountain ash, ought to be good for about 25 to 30 years.

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Tree owners will often go to any length to keep a declining tree alive. Photo: Evelyn Simak, geograph.org.uk

However, no tree lives forever. Many begin to decline as they reach the limits of their average lifespan: major branches die back and aren’t replaced, wounds no longer heal well, the trunk becomes hollow, etc. Desperate homeowners can sink a fortune into trying to keep a dying tree alive: insecticide or fungicide treatments, careful pruning, props, fertilizations, watering, etc. and yet they often continue to decline.

And trees sometimes die or decline well before they should. Just like some people die young, so do some trees. That’s just life! They could be infected by a disease, have been hit by lightning, suffer root damage due to vehicles parked on their root system, etc., but most often, there is no clear explanation.

Essentially, when you plant a tree, your hope and expectation is that it will live and thrive as long as you inhabit your home, but sometimes it simply doesn’t. And when you buy an older home with older trees, the chances of gradually losing some of them increase.

Now That It’s Dying

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A dead tree left standing can still be useful. Photo: Des Blenkinsopp, geograph.org.uk

When a tree is dead or in serious decline, the first reaction of most homeowners is to have it removed. That’s a wise and legitimate decision if there is any danger the tree could hurt people or cause damage to property when it falls. Also when it carries a disease or insect that could spread to and kill surrounding trees (Dutch elm disease, emerald ash borer, etc.).

But what about an older tree gradually declining in the far corner of your yard, well back from the house or parked cars, or in a forested area?

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Pileated woodpecker nesting in a dead tree. Photo: Skeeze, Pixabay

Declining, dying or dead trees (snags) are a vital part of any thriving ecosystem. One third of all woodland birds nest in holes or cavities in dead trees, including woodpeckers, owls, and wood ducks. Bats (already severely threatened in many areas), flying squirrels, raccoons and many other mammals also depend on them. Birds of prey use them as lookouts and food handling points.

A host of insects and mushrooms feed on dead wood, sight unseen … and they in turn feed birds and mammals.

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Even when a tree falls, it continues to contribute enormously to its environment. Photo: Akabashi, Wikimedia Commons

Even when a dead tree falls, it contributes to the environment. As it crashes down, tearing limbs off neighboring trees, crushing smaller ones, it opens a light gap in the forest, allowing understory trees to grow and thus the the forest can renew itself. The trunk, if left to lie where it falls, slowly decomposes, feeding and hosting a wide range of animals and fungus of all sorts when it does. Plants and mosses grow on the fallen tree and some trees species even sprout there before going on to become forest giants in their turn.

Wherever possible, the ecological thing to do is leave dying and dead trees standing. And even when they fall, do move the trunk off a path or road, of course, but try to leave it nearby to gradually rot away and enrich the soil.

Where possible (again, I repeat that there are places where you can’t legitimately leave a dead tree standing), just leave the tree to die gracefully … but do think of planting a replacement!20170810F Eng Clkr-Free-Vector-Images

Trees are always wanted, dead or alive!20170810F Eng Clkr-Free-Vector-Images

August Is the Time to Order Fall Bulbs!

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For beautiful spring flowers, you have to order bulbs in the fall. Photo: Longfield Gardens

If you intend to plant bulbs for bloom next spring—tulips, daffodils, squills, hyacinths, crocuses, etc.—or autumn-flowering bulbs—autumn crocuses, colchicums, etc.—, late July or August is the time to send in your orders!

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Always finding the same old bulbs in your local garden center? Mail order sources will vastly broaden your horizon! Photo: iBulb

True enough, a certain choice of bulbs will show up in your local garden center in September … but not necessarily the varieties you want. My local garden centers seem to offer almost only Triumph tulips, for example, yet they’re short-lived bulbs and I prefer perennial tulips (botanical tulips, viridifloras, Darwin hybrids, etc.). And they sell the same crocus varieties year after year, whereas I want ones I don’t already grow. Plus, they offer no rare bulbs at all, just run-of-the-mill varieties.

For a reasonable choice of bulbs, I have to order from a bulb specialist. And if you’re a serious bulb gardener, you’ll eventually find yourself in the same position.

For an eye-opening choice of bulbs, Canadian gardeners can try Fraser’s Thimble FarmsBotanus, Phoenix Perennials or Veseys. Americans will find a wide range of choices at Brent and Becky’s Bulbs and Longfield Gardens.

Have yourself a great bulb shopping spree!