Invasion of the Cabbage Whites

2016-03-02 14.24.23The small cabbage white butterfly (Pieris rapae) is the bane of gardeners’ existence all over the world. Native to Europe, Asia and North Africa, the butterfly is now found throughout most of North America, Hawaii, Australia and New Zealand.

In my little corner of New Zealand, the butterfly is especially common, presumably because of the huge numbers of commercial brassica crops grown here. In late summer, the roadsides shimmer with the butterflies, and their tattered wings flutter like flags in my car’s grille.

These butterflies are the reason broccoli is a seasonal crop for us. Broccoli can be grown year-round here, but mid- to late-summer broccoli becomes infested with caterpillars. For a few years, I dutifully treated my broccoli with Bt (an organic bacterial toxin that selectively kills caterpillars), but I eventually stopped bothering.

By mid-summer, there is so much other food coming out of the garden that, truth is, we don’t need the broccoli. And having a broccoli-free part of the year helps bring variety to our diets, and makes broccoli more special when it is available in winter and spring.

Sour grapes? Not at all! Just learning to work with the local wildlife instead of against it. Makes life easier for everyone!




Solanaceae—one of my favourite families of plants.

There are more than a few members of this family in the vegetable garden:

Tomatoes, potatoes, eggplants, cape gooseberries, capsicum (peppers), and tomatillos are all solanaceous plants.



But they don’t end there. In the flower garden there are petunias and nicotiana, among the perennial fruits are gogi berries, and in the native garden there is poro poro.

And, of course, growing as weeds everywhere are black and hairy nightshade (these don’t get my favourite plant vote).

This diverse and sometimes tasty group of plants also includes many containing medicinal, poisonous or psychoactive chemicals (tobacco, mandrake, and deadly nightshade among them). Indeed, it’s best to be careful with the Solanaceae—even the edible ones contain poisons in the non-edible portions of the plants, or, as in the case of green potatoes, even in the edible parts. Solanine is the culprit in green potatoes—it causes diarrhoea, vomiting and hallucinations, and its bitter taste prevents herbivores from eating the potatoes. Other chemicals in the Solanaceae can have the opposite effect—reducing nausea in chemotherapy patients, and reversing the effects of poisoning by certain pesticides and chemical warfare agents.

And we’re still discovering more uses for these pharmacologically rich plants.

What’s not to like?


100_4002Planting out, I scrutinise each plant for health. I discard damaged or poorly growing plants. I pick off pests.

But there are some problems I can’t do anything about.

The neighbour’s 2,4-D overspray is one of those.

2,4-D is a broadleaf herbicide that has become increasingly popular with our neighbours over the past five years. Unfortunately, it is extremely volatile, so if the wind is blowing our direction when they spray, we are enveloped in a cloud of herbicide.

It usually doesn’t kill our plants outright, but it has long-lasting effects on them. Grapes are particularly susceptible, but we’ve had damage to nearly every vegetable crop in some years. Some plants, like the green beans, seem to be able to ‘grow out’ of the damage. Others never do, and the effects of an early spring spray can still be seen at harvest time in late summer.

This year, the first overspray hit us in mid-October. Though the frost-tender crops weren’t in the garden yet, they were in the greenhouse, and didn’t escape damage.

I’d surveyed the damage in general as the plants were massed in the greenhouse, but as I inspected each plant at plant out time, I saw the full extent of the damage.

The most obvious early sign of 2,4-D damage is deformation of the leaves—they elongate and curl, and develop odd-looking venation. They can also bleach, sometimes looking nearly white. This year, the tomatoes were particularly hard-hit, with almost all the young leaves deformed. Eggplants, too. Thankfully, the peppers seem to have escaped, and many plants weren’t even up yet, so they made it, too.

I accept that my neighbours aren’t organic farmers, and that they have little control over when the contractor comes to do their spraying, but still it is discouraging to face the same overspray problems year after year.

Almond Conundrum

100_3428Well, there they go—the last of the almonds. The last I will buy for a long time.

I absolutely love almonds. They’re one of my favourite nuts. But I had already replaced most of the almonds we eat (which come from California, producer of 80% of the world’s almonds) with locally grown walnuts, in my effort to eat closer to home. Now, however, they’ll be a very rare treat.

In my post last week about our relationship with bees, I talked about how North American bees are forced to forage in agricultural monocultures, leading to poor nutrition and exposure to pesticides. The largest of those monocultures is in California’s almond growing region, where the bees are “parked” every year during almond flowering in order to pollinate the trees.

Add to that the gallon of scarce California water that goes into producing each almond, and I find I can’t keep buying them. At least not the ones at the grocery store.

BUT, in deciding that, I’ve discovered that there are NZ almond growers as close to us as Marlborough, and that, with a little coddling, we might even be able to grow them ourselves!

So, with that, I have cheerfully sworn off California almonds. I’ll be checking out my local nurseries for almond trees, and tracking down those locally produced nuts!

A new relationship with bees

DSC_0005 cropMy friend, Maryann, researches pollinator decline. Her focus is on honey bees, and how honey bee management can affect bee health.

The picture is a complex and disheartening one, but one that offers glimpses of what sustainable bee management could look like. Wherever they live, honey bees are beset by an array of diseases and parasites. Under the non-intensive, almost natural management regimes used in much of Africa, the bees fight off these pathogens and parasites without intervention from bee keepers. Intensely managed North American hives crumble under their onslaught.

North American hives are shifted from place to place, following the flowering crops, in order to provide pollination services for huge monocultures of fruits, vegetables and nuts. Hives are packed close together in vast arrays, making it easy for disease to spread from hive to hive.

The heavy use of herbicides in the agricultural landscape mean that the only source of pollen and nectar may be the crop to be pollinated. Bees evolved to feed on a wide variety of flowers, and cannot survive on one food alone. Imagine being forced to eat only broccoli—it’s good for you, but if you ate nothing else, your health would suffer.

Add to malnutrition the fact that the pollen the bees are eating is laced with no fewer than 137 different pesticides, many of which are toxic to bees or interfere with their growth, development and learning. And these pesticides are mixed with a range of substances to help them stick to the plants or disperse evenly when sprayed; these chemicals can be as poisonous to bees as the pesticides, and they are virtually unregulated.

Poor nutrition, poisoned food, and crowded conditions make North American bees susceptible to disease and parasite outbreaks. Bee keepers’ response has largely been to treat hives with pesticides to kill the parasites that spread disease, further adding to the chemical load the bees must support. When parasites develop resistance to pesticides (which they do at an alarming rate), the weakened bees are overwhelmed, and the colony dies.

I have long been uncomfortable with the North American management of bees—we squeeze everything we can from the poor animals, pushing them to their physiological limits in poor conditions. It’s no wonder they are in trouble. If we forced any other livestock to live in overcrowded conditions and eat poisoned food that didn’t meet their nutritional needs, the public would be outraged. Now, this unsustainable management has created a crisis, as the animals we depend upon to produce much of our food die in unprecedented numbers.

We need to develop a more gentle approach to bee management—one that respects the needs of these little animals. We need to critically evaluate (and curtail) our use of pesticides, and reconsider our model of vast monocultures in favour of more mixed agriculture. We need to give bees a break from the agricultural landscape so they have opportunities to eat food not laced with pesticides. We need to manage bees less for our own convenience, and more for their health and well-being. We need a new relationship with bees, forged from an understanding of bees’ needs, and aimed at long-term sustainability.