The very best way to weed is smothering, also called mulching. It’s an oldie, but a goodie. No straining or digging required, it’s as easy as an armload of whatever mulch I have lying around dumped thickly a top the weeds. Feeds the hungry microbes as well – two birds, one stone. Put cardboard beneath the mulch for a bit of extra.
Sadly not all weeds can be smothered. These weeds I call pernicious (and other things not suitable for this post). Though you can minimise them, you may never eliminate them. Either way it takes time and for peace of mind it helps greatly to relate to them as an ongoing thing.
My key strategies are
- Improve your soil. Weeds proliferate in certain conditions – change the conditions and you’ll loosen the weeds grip on it. Mulch, compost, minerals and plant trees. Dense planting is smart – not only leaves no room for weeds, but changes the conditions. Use soil improving dynamic accumulators like comfrey, yarrow, chicory, borage – heaps of ideas here.
- Interplant: Many weedy problems can be overcome with subterfuge. Rather than the huge effort of elimination followed by the constant work of keeping the weed back, sneak up on it by interplanting the weedy area with taller shrubs or trees and competitive groundcovers. When a weed is no longer dominant, rather interspersed amongst other plants that you love, you’ll stop worrying about it so much. You may need a few stabs at it to work out which plants will outcompete your weed — but it’s a far easier, gentler approach than spraying off an area and laying it bare, calling in a whole new guild of weeds.
- One years seeding is seven years weeding. If you don’t want it, then don’t let it seed.
- Make weeding a little and often event.
- Animals come to the rescue – goats for thistle and blackberry, chickens for wandering willie and oxalis, pig for convuluvlulus. Create animal runs along fence lines where incoming weeds arrive from your lovely neighbours.
- Can you live with this weed? Use it to provide biomass for compost heaps or notice that the bees love the flowers or use it in your salads or feed it to your chooks.
Buttercup, inkweed and dock
Cut seedheads off dock and inkweed during growing season. I whizz round the paddocks with the weed eater. A tractor mow would be more appropriate were we on a larger block.
On small sections grub or dig out the day after it’s rained – trust me its easier this way. Over time, the improvements in your soil will soften your soil and these guys will love it less.
Gypsum or woodash plus minerals in spring will slowly but surely turn this ship around.
Convulvulus and Lotus Major
Vines are tough customers. At my place, nourished in our claybase soil – convulvulus winds for miles and miles, smothering all in it’s path. We have tried every trick in the book.
On bare ground lay carpet in spring before the new growth gets going. Cut off any growth that peeks out the sides over the summer. Once the autumn rains start and the ground softens, roll the carpet up and marvel at the long strings of roots that come with it. Light an autumn bonfire in the orchard and throw the carpet on. Go over the area with a fine tooth comb getting up any last piece of root – throwing them on the bonfire as you go. Plant up straight away – nature abhors a vacuum.
This is how we cleared it from the area that is now the potager. All these years later we get the odd little bit resurfacing and I patiently follow the white root back to source and whip it out. It’s easy to do now that the soil is healthy and soft and I’m getting it while small.
Pigs love convulvulus root and we use Nellie to this end to root up those protein rich roots over winter along our south and east fencelines.
Where convulvulus winds through existing plants – well, we’ve got a problem Houston. The roots twist through existing roots and set up a home. This is what we have along our northern line and I havent found a way to destroy them organically.
After years of battling this monster manually, I spread my search into chemical solutions. Knowing I would never spray, I wasn’t sure there’d be an answer here. But there was. I found cutnpaste. A roll on glyphosate developed by kiwi park ranger Andy Spence. Until there is another option, this is the only thing saving my orchard from being completely covered in this fast growing, insidious vine.
Every year in December we dab the ends of the new growth and every year less arrives. None of the flaxes or corokias or manukas that share the space have ever so much as turned up a leaf. The guys at cutnpaste are working on a glyphosate free alternative, which I will jump on as soon as it is available. Meantime, this one works brilliantly. And I’m happy to save my orchard, no spray drift required. The difference between roll on and spray is massive.
Like all weed infestations, your management depends on how big your land and serious the problem. On an acre or less, I’d happily hand grub the blackberry and employ a goat to gobble the new shoots or dab on cut n paste until it was sorted.
Once the bulk is handled, soil improvements and dense planting will stem the tide, but as with all established weeds – management will be ongoing. Bring the soil life with mulch, biological sprays and mixed plantings. Blackberry is an open ground, edge weed so the more trees you plant, the less it’ll flourish.
On more than a few acres of blackberry filled land either clear it out with a digger then use cut’n’paste or goats on the regrowth. You may need a one off taming spray to be able to get to the ground to replant the area.
Consider leaving some for your own fruit supply.
Tradescantia (wandering willie)
This little weed is serious in bush because it puts a halt to regeneration, flourishing in the light gap made when a tree dies and stopping new natives coming up.
Chickens love tradescantia. They’ll clean the area up for you in the best way possible. If you are chicken-less rake it all up, hunting out every last scrap. Stuff it into a black plastic bag and leave it down the back of the garden somewhere for a year or more. Turned to sludge, it’s a nutritious addition to your compost.
Alternatively I’ve had good success with laying clear plastic over the infestation and letting the sun fry it.
Dense planting including groundcovers will outcompete tradescantia if you eradicate it first. While new plantings establish, keep on top of new bits that come through.
Kikuyu spreads out via runners below and above ground while couch (or twitch) runs below the topsoil. They are both really determined grasses.
In open areas, knock the grass back by laying plastic on top for summer and autumn — or until it’s died off, then lay cardboard thickly, pile the mulch on and plant a guild of soil enriching equally determined plants. Soft and gentle will not do it! Fast growing nitrogen fixing trees teamed up with vigorous tap roots and tenacious groundcovers work a treat. Don’t turn your back though.
If these grasses are in your vegie patch, keep on keepin’ on with weeding them out, at the same time adding loads of compost and mulch to loosen their grip on the soil. The roots that peg them down will get further and further apart, making them easier to manage in time. I’ve suggested ‘little and often’ for weeding generally but it really is the key here, and a long term view.
Where kikuyu is aggressively taking over existing plantings, consider using Cut’n’Paste on it until plantings establish. Ever after keep it in check with mowing, grazing, mulching or a combination of all three.
High on your list as a pernicious weed, and I understand it is annoying! But it’s so small and shallow rooted and self-contained that it barely competes for nutrients.
If your mental health relies on its removal then you are in for the long haul. Prepare yourself. Baking soda spray at the rate of 1tablespoon per 500ml water sprayed under the sun at regular intervals to eventually wear the bulbs out.
Smothering works well too. I’d baking soda spray in a determined way until the foliage has completely died off, then lay carpet and build a new bed on top so I didn’t have to disturb the bulbs in the soil beneath. If you have chickens then rejoice – they love oxalis as much as you don’t.
Salt. Buy a 20kg bag of fine Ag salt from Farmlands. Dollop a handful on top of weeds.
Chickweed, dandelion, nettle, mallow, puha, fathen, and wild onions are all good for dinner. Try them out – you’ll wonder why you bother gardening! Do identify correctly. Check out Simply Living by Gwen Skinner or A Foragers Treasury by Johanna Knox.
A One off taming spray
In all my years consulting I’ve only twice recommended spraying. You really don’t want to spray if you can avoid it.
But sometimes the scale and tenacity of a weed problem requires a spray off before Eden can be created. Sometimes no other options work because of steep ground, lack of access, no fencing or the sheer intensity of the weed.
Use spray as a tool to clear difficult land but not for ongoing management. Thoughtful design, dense plantings, mulch, minerals, biological sprays and a commitment to being spray free will make it so.
Spraying is insidious. The particles and vapour spread further than the little bit you just sprayed, and hang round longer too.
Though this quote is for pesticides, it is reflective of the impact of spraying regardless of what the spray is.
“95% – 98% of applied pesticides miss their target, reaching nearby people and wildlife, waterways, soil and air” Source: Miller GT (2004), Sustaining the Earth, 6th edition. Thompson Learning, Inc.