First published August 2008, last updated April 2012

I used to define a weed as anything that couldn’t stand up to my lawnmower or required too much care. It was also incredibly important to me to have a well manicured lawn and garden. I hate to think how many hours I spent mowing a lawn when it really didn’t need it and also the gallons of herbicide I used.

I still admire a well manicured lawn and a tidy garden, but my thinking has changed over the last few years and I also appreciate “cottage” type gardens that can often seem quite chaotic and weed infested.

After all, sometimes a weed is just a plant in the wrong spot and our views have often been shaped by our parents and peers as to what constitutes a “good” garden.

Weeds in rehabilitation/revegetation

While some weeds are incredibly invasive to the detriment to every other plant in its path, sometimes they can save a landscape from further degradation.

One of the most interesting applications of using weeds for rehabilitation has been carried out by Australian, Peter Andrews, as part of what he calls Natural Sequence Farming.

Peter theorized that weeds were growing in a particular area as the soil wasn’t in good enough condition to support native species; so he let them grow – even encouraged them. Over time, native species took over and balance was restored.

Peter has also relayed the story of being in a British paddock and complimenting the farmer on its weed free status. The farmer was insulted as in that part of the country a healthy sprinkling of weeds in amongst the pasture was a sign of a healthy paddock.

Peter’s book, “Back From The Brink” is one of the most fascinating publications I’ve ever read – plenty of “doh” moments for me in that. If you get a chance to read a copy, you won’t regret it – many of his strategies can be applied in small gardens also.

Weeds and climate change

The climate is changing – I guess that’s not news to many people. This means that plants we’ve come to know and cherish in our gardens may no longer do so well. Some grasses are just too thirsty for some areas with decreasing rainfall and what may have been considered “weed” grasses in some places, such as kikuyu, may become necessary if you’re wanting any sort of groundcover.

The availability of water supply in the future is something that all gardeners should keep in mind when considering what to plant. Hedge your bets – if you’re in a traditionally wet area, plan on it getting wetter – and vice versa for dryer climates.

We may not have a lot of choice about getting along with weeds as researchers have found that they positively thrive in areas where a high level of carbon dioxide is present in the atmosphere. Weeds are also becoming increasingly resistant to herbicides such as glyphosate.

Useful weeds

So for a moment, cast aside the prejudices you may have when certain weed names are mentioned and let’s take a brief look at some of the positive attributes of plants that commonly invade our garden.

Generally speaking, weeds do help with breaking up and aerating soil, fixing nitrogen and providing organic material when they die. Here are some specific weeds and their uses.

Dandelions

I remember my Dad cursing dandelions popping up everywhere. My brother and I weren’t helpful in this as we used to love playing with the “puff balls”, which contained all the seed. It’s been *years* since I saw dandelions in any quantity; so it seems gardener rage has had an impact in the places I have lived. But when you stand back and think about it – aren’t they a beautiful flower?

They not only provide a splash of color and food for bees, but they are edible. The petals can be used as a garnish and young leaves can be added to a salad. You can also make tea and wine from dandelions. Researchers have also discovered dandelion root sap can be economically used in the production of high quality rubber.

Couch grass

Couch grass is used in herbal medicine and the roots can be dried and ground to make a flour for breadmaking.

Bracken

Bracken is one of the oldest and most successful members of the fern family. It can be used to make glue, soap, fertilizer and mulch.

Milkweed

Certainly considered a weed here in Australia, milkweed is the primary food source of the incredibly beautiful Monarch butterfly. It’s also used in herbal medicine for a variety of ailments.

Clover

I have to admit I’ve always liked clover as a ground cover – it’s so lush. It’s another weed that has a nice flower and bees love it. Clover also handles compacted soil better than lawn grass and has longer roots that enable it to access moisture from deeper in the soil.

Nasturtium

Not always considered a weed, nasturtium is a good companion plant for vegetables and all part of the nasturtium are edible.

Wild mustard

Seeds are edible and also suitable as a companion plant to act as a host of nematodes and many insect pests.

Chickweed

Edible and used in alternative medicine.
 
I’m certainly not a master gardener or expert on plants and I’m sure just about every weed is useful in some way. If you know of uses for a particular species, please share the info below!
 
Note: before actively encouraging any ‘useful weeds’; check your local laws. Some can also be particularly troublesome in terms of spreading past your own boundary – you don’t want your neighbours showing up on your doorstep armed with with torches and pitchforks.