In the Weeds
What are weeds exactly? It appears one man’s weed is another man’s feed... or shade, or even something that can help rebalance soil. Jim Annear takes another look at these much-maligned plants.
What are weeds exactly? It appears one man’s weed is another man’s feed... or shade, or even something that can help rebalance soil.
Jim Annear takes another look at these much-maligned plants.
We’ve all heard a plant be called a ‘weed’ before, so why is it that some plants are called weeds while others aren’t? What makes a weed? It’s a question that I have long been intrigued and confused by.
There have been countless times where I’ve become fascinated by a plant and then, soon after, get told it’s a “bad plant”, a “pest” or a “weed”. From a young age, I remember my grandparents stepping out on sunny afternoons for “a spot of weeding”. And I remember learning the words “invasive species” when out walking in our native forests. So is it just a case of personal preference, like
when somebody says it’s a bad day just because it’s raining, or is there more to this weedy story?
The word itself has a bit of a stigma to it. Weed. Besides being a popular nickname for the fast growing and short lived Cannabis genus, it’s usually spoken about in an undesirable tone. I grew
up understanding that weeds were unwanted plants. And if you found one of those suckers, well
then, out comes the miracle wonder juice, the good ol’ glyphosate (usually in the form of Roundup)
to spray the day!
But there’s another way to look at weeds. There are people who listen to and study weeds. In the
book When Weeds Talk, American organic farmer Jay L McCaman explains the link between weeds and soil fertility management. He claims that weeds act as indicators of conditions beneath the surface, in particular imbalances in soil nutrients. Even more interestingly, he observes that once
the soil has been rebalanced, the weed will simply no longer grow there.
Therefore, by correctly identifying what weeds dominate an area, we can start to get a good idea
of what adjustments need to be made to improve the soil. An example of this is the common dandelion — unlike many other plants, it grows well in soil that’s low in calcium, due to its ability
to mine calcium from down deep and bring it back to the surface. This shows that weeds can
actually play a role in healing damaged, degraded landscapes by indicating what the soil is lacking, while simultaneously being part of the solution!
Another perspective, one that I personally admire, is that many common weeds are not just edible, but are in fact really nutritious and good for us! You might have the lemony tasting wood sorrel
(also known as Oxalis) in your garden, and lambs quarter flourishes in spring in disturbed soil,
such as vege gardens.
Tauranga local Julia Sich of Julia’s Edible Weeds is a weed’s best friend! She champions wild edible greens for their quirky characteristics and high nutritional value. She shows that they’re some of
the best free food out there, thriving in an abundance in nooks and crannies across the wider Bay
of Plenty without anyone’s permission or assistance — you’ve just got to know where to look. Julia has gained a wealth of wisdom from years of interacting with these plants and she holds regular walks and workshops around Tauranga, where you’ll be introduced to an array of wonderful edible weeds.
Different plant species have been introduced to Aotearoa from all over the world. Some of these are invasive plants that have found themselves on the ‘most wanted’ lists of government departments, regional councils and conservation groups, as they threaten our native biodiversity. The threat comes from their ability to disrupt the local ecosystem by growing thick and fast, smothering anything in their way and dominating the landscape.
Take gorse, for example. It may well have seemed like a great idea initially to introduce gorse
(Ulex europaeus) to grow as hedges and windbreaks — as Liz Knight points out in her book Forage, gorse was once highly valued in Britain as a food for stock, a fuel and a soil fixer, and acts were
even passed to prevent over-harvesting. However, it all goes wrong when foreign species like this are introduced and left to outgrow native species and, through the dispersal of its seed, take over large areas of land. Another example is pampas grasses (Cortaderia sp), which have found their way over the Pacific Ocean from South America and now rival our native toetoe grasses (Austrodera sp).
When I went about looking for a set list of weeds in Aotearoa, I discovered that it isn’t that straightforward, as these lists are subject to change, but two things stand out to me about plants deemed to be weeds. Firstly, weeds are really, really good at growing. Almost too good. This is
what lands them in trouble as, if left unmanaged (for example, in native bush), they can cause a lot
of problems in a short amount of time. But that’s the other thing — out in the wild they can easily
wreak havoc, but if they’re grown in a managed environment, can they be utilised in a good way? Well, it’s a yes from me.
For example, a couple of years back I planted out some fruit trees with the aim of establishing a
food forest area and I chose to include two brush wattle trees (Paraserianthes lophantha), originally from Western Australia, even though they’re considered a pest all around the country. Their fast and vigorous growth meant they quickly provided a canopy shelter for the slower growing fruit trees that eventually sat underneath, then when they got too big and before they had any chance to create seeds, I chopped them down, chipped them up and mulched underneath the fruit trees. It worked
a treat, sheltering and feeding the young fruit trees, so I think that the environment and management makes a huge difference in whether a plant is doing good or evil.
There’s a time and a place for all plants. It’s just when a plant is in the wrong place at the wrong
time, that it’s called a weed.
For more gardening content, follow Jim @gardennearsy and @homefarm
For a list of common edible weeds, as well as workshop details, visit juliasedibleweeds.com
For photos and descriptions of pests, visit boprc.govt.nz/environment/pests/pest-plants
Read our previous Grow Together columns
By Jim Annear
Photography by ilk