PhoenixSon

Cactus and weeds

48 posts in this topic

Okay i have a cactus garden bed or two, that im having troubles keeping the weeds down.

I was wondering if there was any herbicides you could use that would kill the weeds and not the cacti of course. I have a couple of dragon fruit cutting so of course it would have to be safe ie degrades and doesnt get pulled up into the plant @ all.

Any idea's?

thanks in advance

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I Have the same problem! and for the last few weeks wanted to ask that same question - in my case its more just grasses of all types.

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Chickens with body armour.

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vinegar. better do some research first but i dont think it kills via root suckup more it draws the moisture away from the leaf. many variations including soap and salt but the basic method is cheapo vinegar in a spray bottle 100% and spray on the localised area. so theoritically if you dont spray or splash it on your nice plants then it should be ok. but i have no idea on the true science of soil PH and what else it might effect so yeh proceed with caution.

for example i had a front yard garden bed of which my front yard grass area decided to take over, i got a tad lazy and instead of turning the shovel and doing the hard work i simply covered the grassy garden bed in mulches and woodchips in an attempt to starve them out....it worked in some places but this particular patch now has become grass infused mulch woodchip weeds and i cant even get a shovel in now it has become to strongly interwoven. i used the vinegar and now i have a grass free woodchip bed again, and it does not seem to have poisoned the normal plants close by.

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A thick layer of newspaper or cardboard, placed directly on top of the weeds, then mulched heavily. Perhaps not best for cacti, though I'm sure water tolerant species would be fine.

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If only I could somehow get some snail leashes...

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yeah i have tried the chooks out actually they do an okay job, but i need to fence the area off or else im spending a whole day out there with sticks keeping the slaves in the right area to weed. good extra ferts from the crap aswell!

But it would be nice to just spray then mulch on top of the dead weeds, thing is i dont have ze money for enuff mulch for the garden so im going for the chemical intervention at the moment.

Ive seen a video of PD's garden and it looks like where his cactus are there are no weeds at all... wonder what he uses?

Thanks for the vingegar idea santiago might use it in different area's but maybe not the cactus spot.

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I have a problem at the moment with grass growing from the middle of an old large TBM, I have up-rooted it and pulled all the grass out an then re-plant it and the bloody grass grows again rolleyes.gif It has beaten me I'm out of ideas.

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Cacti don't make it easy to keep them weed free!

You can actually do away with the mulch and just use cardboard weighted down with something. It looks ugly, but is weffective.

Alternatively, you can get monocot specific herbicides. I wouldn't use them personally, but others have fewer objections to using chemicals than I. TI would probably know of a good one.

HN, have you tried cleaning the roots of all the soil before potting back up?

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ducks

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Chickens don't need body armor it seems in my garden they need muzzles! They'll try and peck at even the spiniest of my cacti friends often to no avail for them but they still peck solid holes in everything!

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Ive given up on seriously combatting them, just pull out what i can ever week or 2. I dont think the weeds do much harm anyway, what are they going to do, steal some water or nutrients from my slightly over watered over fertilised cacti garden?

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Ive seen a video of PD's garden and it looks like where his cactus are there are no weeds at all... wonder what he uses?

seriously guys, the answer is way too obvious, and thankfully, cactus are really not susceptible to most herbicides, same with any succulent.

i would be a lot more careful around almost any other type of plant, but with cactus it is more than sufficient to pull away any foliage growing up the cactus itself and flatten it against the ground. spray with glyphosate (roundup) no more than once a fortnight, no less than once in three fortnights.

residues break down completely in the soil within about two months in many cases, and root uptake is not an issue unless we are talking very bare, very sandy soil. just don't soak the soil in it, there's no need to blast weeds with spray, you are applying a layer of droplets to the leaves not trying to hose them out of the ground.

edit: oh, and use a correct mix rate or you only increase the (low) chance of harming the cactus. ten mLs to the L of a standard 360g/L formulation is perfect for most situations.

if you had to kill a prickly pear with a thorough foliar spray of glyph360, i swear to god, you'd have to mix one part chemical to one part water.

1:100 to kill nearly any annual weed

1:1 to kill prickly pear cactus

Edited by ThunderIdeal
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Alternatively, you can get monocot specific herbicides. I wouldn't use them personally, but others have fewer objections to using chemicals than I. TI would probably know of a good one.

yeah as lokstok said and i have said before, fusilade is an option for grasses but i really can't endorse it. it isn't super effective and without having the facts in front of me, i guarantee it is far more hazardous than friendly old glyphosate.

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watered down vinegar is a contact killer, it burns the tops away and isn't the only organic option that works this way. i'm really interested in organic contact herbicides but apart from an organic farm but it's gonna take a real paradigm shift before they get any serious attention. the problem with contacts is that some weeds can survive having the above-ground part destroyed after only sprouting just a few weeks ago. that is probably why contacts don't have much commercial promise as long as systemic herbicides are around.

eatfoo raises a good point, are the weeds actually a problem, can you use cultural methods? hoeing is pretty good. i actually use the toe of my boot as a hoe throughout the day because its a good lazy option.

you're in my climate spacemonk so if you provide names or photos of weeds i can describe other methods/chemicals but glyphosate is probably the go.

Edited by ThunderIdeal
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I know PD uses or at least has used Glyphosphate, he posted about it causing major damage to his plants due to over spray. I occasionally use it for areas of my yard but never near my cacti, I don't want to risk them.

Tripsis the problem is the rootball/mass makes it very difficult to to clean out, I may even give that selective herbicide a try.

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Ive given up on seriously combatting them, just pull out what i can ever week or 2. I dont think the weeds do much harm anyway, what are they going to do, steal some water or nutrients from my slightly over watered over fertilised cacti garden?

The things that bother me is nute competition and the fact the all the weeds hold a lot of dew that is going to increasse rot, also increases spots that slugs are going to live in. It boils down to a time thing sometimes i have the time to do the weeding a lotta of the other times i dont, i have a decent square meters that i need to prowl so yeah im not lazy at all :)Alsob would like the look of it aswell

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seriously guys, the answer is way too obvious, and thankfully, cactus are really not susceptible to most herbicides, same with any succulent.

i would be a lot more careful around almost any other type of plant, but with cactus it is more than sufficient to pull away any foliage growing up the cactus itself and flatten it against the ground. spray with glyphosate (roundup) no more than once a fortnight, no less than once in three fortnights.

residues break down completely in the soil within about two months in many cases, and root uptake is not an issue unless we are talking very bare, very sandy soil. just don't soak the soil in it, there's no need to blast weeds with spray, you are applying a layer of droplets to the leaves not trying to hose them out of the ground.

edit: oh, and use a correct mix rate or you only increase the (low) chance of harming the cactus. ten mLs to the L of a standard 360g/L formulation is perfect for most situations.

if you had to kill a prickly pear with a thorough foliar spray of glyph360, i swear to god, you'd have to mix one part chemical to one part water.

1:100 to kill nearly any annual weed

1:1 to kill prickly pear cactus

Awesome thanks a lot for that, if i can kill the general lot i can weed out the rest by hand if any are resistant!

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I know PD uses or at least has used Glyphosphate, he posted about it causing major damage to his plants due to over spray. I occasionally use it for areas of my yard but never near my cacti, I don't want to risk them.

Tripsis the problem is the rootball/mass makes it very difficult to to clean out, I may even give that selective herbicide a try.

bugger not spotting this thread in view new content, hope i'm not too late saying this.

if PD hurt his trichs using glypho, that means one or more of three possibilities

a. he mixed it strong

b. trichs etc are far more susceptible to glypho than Opuntia

c. i. he put too much spray mix into the soil and had significant root uptake

c. ii. the cactus soil was so low on colloids (clay, humus) that soil adhesion was minimal, allowing significant root uptake

just take it easy if you love your plants, be very mindful of the wind and be aware that even though they usually aren't illuminated by the sun, when droplets hit with speed they splash a long way. adjusting your knapsack to mist is one solution to splatter, but mist drifts in the wind and the droplets don't stick as effectively as slightly larger droplets do.

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I've heard cactus can't take up round up at all don't quote me on that and Id never try it on my plants but i have splashed it on a few at work and they didn't seem to mind

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okay from the looks of it at least some ornamental cactus can safely be sprayed with fusilade. apart from withholding periods i am using information from an american label.

http://www.cdms.net/ldat/ld63N010.pdf

Barrel cactus - Ferocactus sp

Cholia cactus - Opuntia cholia

Hedgehog cactus - Echinocatus sp

Saguaro cactus - Carnegiea gijantea

copied letter for letter although seems it might have spelling errors. an incomplete list for sure, i think if your mix rate is low enough then selectivity will be very high so practically all broadleaf plants will not be harmed.

Realistically the stuff can be sprayed over your food as long as withholding periods of up to about 17 weeks are observed (or much less depending on the crop).

if i haven't already mentioned i do use this chemical pretty frequently so i can vouch for it even if it doesn't wipe couch out in a single application. i guarantee you that hand-weeding is probably less effective unless the soil is really loose and you are experienced in teasing out all of the rhizomes.

very soon i'm going to rescue somebodies horde of neglected cactus (in pots and in the ground) with fusilade because it's the only realistic option. they are mostly column cacti of various health.

if anybody SHOWS INTEREST then i'll fully document and photograph the process and results

notes for best results:

apply to growing, non stressed grasses, water or fertilise a week before if necessary

perennial grasses (eg established couch) can have their rhizomes and stolons attacked (cut) beforehand to encourage more shoots

use typical herbicide spray gear at least one hour before rainfall

don't disturb grass for a week after application although disturbance (cultivating) after three weeks may help

Edited by Mod! No Discussion about consumption please!

Edited by Evil Genius

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yeah as lokstok said and i have said before, fusilade is an option for grasses but i really can't endorse it. it isn't super effective and without having the facts in front of me, i guarantee it is far more hazardous than friendly old glyphosate.

lol, i guess i've changed my mind. you could almost conclude that handling glyph is less risky simply because it isn't schedule 6 like fluazifop (fusilade), so read up on the safety and especially follow the written precautions when decanting.

i do endorse it though, because sometimes it's the only option that is workable. if you can take out most of the grass with glypho, without harming your plants, do that first.

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In the amount of time spent typing replies in this thread, you could have gone out and weeded by hand :).

Poisons in the garden - not for me !

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Lol yeah u cn't beat a push hoe for in between trichos.

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