Weeds would have to be one of the most dreaded aspects of gardening, especially in the subtropics where growth can be rampant. Most people see them as the enemy, to be eliminated at any cost and conquered with extermination on sight, followed by loads of imported mulch. They believe if they are dedicated enough to their sacred mission that one glorious day the weeds will be gone and they can finally rest and just enjoy their garden.
This was once my approach to weeds as well, but since moving to a zero input approach things couldn’t be more different. The inspiration for this post was a path in my vegetable garden that needed attention. It has a pretty solid cover of blue top (Ageratum) that was starting to flower, with a scattering of cobblers peg (Bidens) also about to seed. Both of these can be fairly imposing plants, especially for young seedlings just getting started.
Conventional wisdom would say I made a grave error in letting the weeds start to flower. The only way to eliminate them is to kill them shortly after germination. In my situation eliminating these species is a pipe dream no matter how hard I try. The fields outside the garden have acres of both species, far too much to even imagine eliminating. Bidens seed move about on clothing and animals, and Ageratum are like dust that blow on the wind. The garden is surrounded by a hedge of tree marigold (Tithonia) that stops the grass running in but also makes a haven for a few Bidens and Ageratum. I would rather deal with seedlings of these species than grass runners marching in from the outside so the hedge is a net positive.
Either way seed will always be finding their way back into the space. And I am quite happy for them to germinate in the veggie garden in reasonable numbers. There is an old saying that the dose is the poison. A small enough amount of many poisons can even be medicinal. The same goes for weeds. It isn’t their presence that causes problems, rather their abundance, and abundance of one species over another is a consequence of management choices.
In addition to this weeds can have distinct beneficial effects on a garden provided they are kept in balance. Since I don’t mulch my gardens the weeds represent a kind of volunteer green manure that I allow to grow within limits, especially along the paths where nothing else is growing anyway. Provided they are killed off before they produce large amounts of seed there is a net benefit to the system. Some weeds are more problematic to manage than others and allowing the less thuggish species to wander about means less opportunity for the worst ones. Weeds “steal nutrients and water” but I reduce my weed biomass as the season dries out. Their water stealing probably does good during the wet spells. And the stealing nutrients part only happens if you put the weeds in the wheelie bin to go to landfill. If the weed tops (and more important intact underground root systems) are left in the garden all those stolen nutrients are returned, multiplied by additional carbon added to the soil. It is like accusing a neighbor of criminal behavior when they pick the fruit falling off your tree and return it as a tasty pie.
My tool of choice today was my favourite hoe. It is a fairly heavy head that I don’t keep especially sharp, but give a touch up with a whetstone now and then. It is on a long handle and has reasonable weight, so it is quite good at chipping out larger plants when needed, and moving soil to form beds as well. My lighter, sharper hoes are better for working smaller weeds in the beds close to valuable plants and in softer soil. If you have never used a hoe before then be aware that many of the models sold are cheap and poorly designed, especially if the handle isn’t long enough. They often don’t come presharpened and are instruments of torture in that state. They should have enough of an edge to cut through a watermelon with moderate pressure, but for heavy hoes be blunt enough to not break your skin, maybe about as sharp as a decent butter knife.
Technique is very important but difficult to put into words. My main advice for a beginner is to go very slowly and pay attention to your technique. Avoid the temptation to creep down toward the head and lean over. This gives you more force but wears you out quickly, and is a good indicator you are getting tired. Practice alternating leading with both hands. If you learn this technique it means you can alternate using different sides of your body and reduce wear and tear on your joints. Other than the occasional deep rooted weed you should mostly be scraping and only lightly chopping with the blade to reduce impact on your joints. And most importantly don’t overdo it before your body can adjust. Even if you feel fine you often find a new prolonged activity like hoeing will cause joint damage when your body and technique have not yet developed. Even now I set myself a limit of one 15 m row per day maximum. Mixing up different physical tasks through the day greatly reduces impact as well.
The job itself is quite pleasant, with ample opportunity to stop, lean on the hoe, and look around the garden to observe things that normally escape you. I like to bite off one piece of the path at a time, about 60 cm of weeds from my feet. This makes the job go faster, kind of like colouring in a page by first dividing it into random triangles to colour one at a time. Each time you finish one you get a little boost of accomplishment, and it presents a good time to decide if you want to stop for a brief rest. I like to hoe a narrow strip down the middle of each segment first. This allows weeds to be hoed on either side then scraped down the cleared middle row easily. The weeds I hoe out are gathered in little piles. This concentrates the organic matter in a mini compost heap, making it easier for worms and microbes to move into it. It also reduces the chance of the weeds regrowing since they are smothering each other, kind of like fighting fire with fire. It also results in a little mound of topsoil and organic matter, that can later be hoed up on to the beds when I reform them before planting a new crop. These mounds also break up the contour of the paths, acting as miniature swales that slow down the flow of water.
Speaking of water, this section first became a bit weedy back in autumn during a prolonged wet spell. Hoeing under these conditions in my clay soil is very unpleasant, with mud flying everywhere. The Bidens and Ageratum tend to come up with a large amount of wet clay stuck to their roots, meaning that even when piled up they are much more likely to simply regrow. During these times I only hoe the spreading grasses to stop them forming extensive mats. Weeds like Ageratum and Bidens instead simply get beheaded repeatedly with a small hand sickle. The tops reattach poorly even during wet spells, so long as they get cut before going to seed the root systems can wait until dry weather. Repeatedly cutting the tops seems to also weaken the root systems and I found them very easy to get out with the hoe today.
The main row took me about 20 minutes to weed through, complete with being followed by a friendly rail that hangs around my weedy gardens and hedges (just visible if you zoom one of the photos). This path will probably get this treatment three times a year, so one hour annually per 15 m long bed, and a bit less on top for the bed itself. I did a little more spot weeding after that to knock out flowering Ageratums that were thinly scattered around the garden. The beds themselves had a decent crop of fleabane (Erigeron) but I left them to sickle later as treats for the goats. Interestingly there was a distinct zone on the path with Ageratum and a little Bidens, while on the mounded up beds only Erigeron was dominant. The few Ageratum in the bed were relatively stunted and very easy to pull out. People like to imagine that weeds are monster plants that will take over any space they can, but observations like this are making me realise they have highly specific needs in order to thrive. I suspect the legends of people conquering weeds happen when they change the details of the soil fertility so much the weeds simply lose interest. We just can’t help ourselves from making perfect environments for weeds to grow in, then complain about it and break our backs trying to hold back the tide. If only we can learn to understand them and to use them they can become both appreciated and useful.