How to inhibit weeds and grass from sprouting

[Philocacti]

Is there a way to inhibit the germination of weeds and grass?

Last year I decided to leave all grass and weeds to grow along with my cacti, it turned out the grew so vigorously that it was very hard to uproot them without disturbing the rootball of my cacti. This year I decided not to make them grow but I can't get to succeed.

Is there a know method that I can apply to inhibit these weeds before they germinate? Or even reduce their number?

It seems their seeds are airborne cuz I tried watering the soil a few days before transplanting and worked for the seeds that were already in the soil, but these weeds keep on growing back.

[~shameless~]

IMO cactus seem to harbour the growth of some weeds, the way the columnar cacti grow seems to make weeds like " creeping oxalis" very hard to pull out manually, also pulling out oxalis seems to disturb any seed pods that i didnt notice and they explode onto all the other cactus next to where im working,

Sorry i dont have anything to add to this topic other than using long nose pliers that are large enough to enable the removal of the weeds with out spiking yourself, even then not disturbing the root ball is very hard.

I see you are in Africa philo, im wondering if you have problems with " creeping oxalis " ???

[zelly]

Is there a way to inhibit the germination of weeds and grass?

absolutely. its an old farming trick. not only does it inhibit the germination of weeds n grass, it does a fantastic job of water conservation. its easiest done if theres no plants to begin with, but still doable for potted up plants, including cacti.

Ok, its gonna take a fair bit of work, but generally speaking its work you'll only have to do once, if you do it correctly

for a potted up plant, take a square piece of 6 mil black plastic, cut into it with a knife or scissors to the middle, where you'll make an X cut, the length of each side of the X slightly smaller than the diameter of your cacti or plant. Slip the black plastic over the top of the pot and around the plant, then overlap the cut portion a bit. If the X cut sides are sticking up, its easier to secure them to the plant by using plastic green plant tape. then secure the black plastic to the sides of the pot in a similar fashion.

weed seeds cant get to the soil & if they do, theres no sunlight for them to grow. bottom water the plant. plastic has to be black.

Do a whole garden like this, making small holes in the plastic sheeting where you transplant seedlings

[franky]

If you want to go down chemical path, there are pre emergant herbecides that will work for you.

[slice]

you can layer with coco, sand, vermiculite, clay pellets, stones and more...just be careful to allow ventilation to your medium.

[watertrade]

I used to be anti herbicide and just tried my best to pull weeds by hand.

It was pretty much impossible for me to do that in some areas because the plants were so close together And spikey. I gave in a few years back and very carefully sprayed roundup. You can just target the grass and weeds not too close to your plants. Wait for them to die and go again. in small steps you have the whole garden done. and if you are getting them before they set seed it helps keep the weeds manageable. Lots of people here probably don't like this approach but I'm a proud and responsible sprayer!

[watertrade]

hi zelly, does that method only work with artificial watering? Just curious if troughs could be sunk to allow rainwater to get under the plastic ?

[zelly]

Just curious if troughs could be sunk to allow rainwater to get under the plastic ?

Farmers around here do exactly that, they have a machine that forms perfectly shaped plastic encased rows with corrugates between them and grow all kinds of food crops. Migrant workers walk up & down the corrugates picking strawberry's, tomatoes, beans etc.

interesting reading on the subject

http://pods.dasnr.okstate.edu/docushare/dsweb/Get/Document-1099/F-6034%20web.pdf

different kinds of plastic row covers (metalized, biodegradable, etc)

http://www.robertmarvel.com/plastic_mulch.html

[Philocacti]

IMO cactus seem to harbour the growth of some weeds, the way the columnar cacti grow seems to make weeds like " creeping oxalis" very hard to pull out manually, also pulling out oxalis seems to disturb any seed pods that i didnt notice and they explode onto all the other cactus next to where im working,

Sorry i dont have anything to add to this topic other than using long nose pliers that are large enough to enable the removal of the weeds with out spiking yourself, even then not disturbing the root ball is very hard.

I see you are in Africa philo, im wondering if you have problems with " creeping oxalis " ???

I haven't seen it grow in any of my pots, but I have something similar which also hard to pull off without getting half of the soil out with h it. So I just fiddle with my hands till I find the main stem, then I just cut it with a scissor.

Zelly- would your method in any way suffocate the root system, which is engulfed with plastic (the plastic pot and the black plastic above).

What about tempreture build up???

In the spring and summer my pots get direct sun all day long. We have a months or a bit more when the temps average from 42-45 Celsius in the sun. Won't these kind of conditions cook the root system?

I'll try it on a pot of 2 this season, and see how'd they react ;)

franky & watertrade - I want to try every "non chemical" way out there before I go this route.

Ogun- I'll give that a go. It'll be easy cuz all the pots that I transplanted 1 year ago, had their soil compacted about 60%, so I have space to give it a go.

Thanks a lot guys for all the feedback

[zelly]

apparently black plastic should be avoided in really hot climates as yeah, it can really heat up the soil, so try clear plastic or one of those breathable weed barrier materials. google weed barrier, amazon com has some inexpensive ones

[MountainGoat]

Hey Philo, down a similar path as Zelly... If you're worried about soil temps, just use newspaper and mulch instead of plastic (it will actually insulate the soil from extremes, lower water consumption, add nutrients, and increase soil activity. Don't worry about pulling out the weeds first, they'll break down with no light and give nutrients to the soil. If you do get airborne seeds as an issue, change the top layer of mulch regularly, the seeds should come out with the mulch. If you also need to create a weed barrier to stop horizontal migration, use comfrey as a 'fence' around the garden (just don't try to dig it up later as it'll then spread). Weeds won't grow through a comfrey barrier, and it is a fantastic mulch. I use newspaper (or cardboard but not in pots) and mulch for just about everything in my garden. You could also try a living mulch which will out-compete the weeds, but not affect the cactus root system (https://www.greenharvest.com.au/SeedOrganic/CoverCrops/LivingMulch.html).

This change in your system will then need to be monitored so that you don't over water and watch for pH variance...

You could also try weed mats, they're great too

[MountainGoat]

Strawberries are farmed in Nth QLD using the same methods as Zelly describes. However, the plants are replaced every year so they don't have to go through the extremes of summer on and under the plastic

[ThunderIdeal]

Clear plastic in summer is called solarising, it gets so hot in summer in the top spade of soil that you almost achieve sterilisation. That will kill weeds, even destroy their seeds, but the cactus presumably would not survive.

[Philocacti]

apparently black plastic should be avoided in really hot climates as yeah, it can really heat up the soil, so try clear plastic or one of those breathable weed barrier materials. google weed barrier, amazon com has some inexpensive ones

Thanks my friend. In 2 days or so, I'm meeting up with a few cacti nursery owners and some other hobbyists like myself and I'll ask them where can I find these barriers here. I'm not going to order anything online again. You've lived that nightmare with me before ;)

MountainGoat- I'll try to improvise with these barriers and layering and I'll report back the results

Too much of a risk ThunderIdeal.

[solaritea]

Corn gluten meal is supposed to help prevent seed germination.

[kadakuda]

I use the black plastic on ym farms as well, i love it and it works very well. Though there is no 100% Ssolve all. black plastic is amazing, but dont get teh platic bag looking material get the woven stuff. the weave may creat small niches for seeds to land on and grow, but so far in my experience only some grasses penetrate it.

Assuming the cactus ou have are big, mulch is the way. teh black plastic mulch is nicer because it wont act as food for pathogens and pests. I mulch extensively with organic mater, but not near my cactus. If you live in a wet area, fungal rot will kick your ass if you are using organic material mulches. I often pile all inds of "mulch/matter" on top of y tree rows then cover with the plastic. it adds nutrition sure, but also much moreair space under the plastic. My black plastic gets up to about80 C and so far have not had troubles growing any kind of perrenial (ie deeper rooted plants). the biggest issues i have are some kind of mle or other burrowing rodent, they love hanging out under the plastic. It also makes it much safer for snakes.

my rows for leafy stuff are usually 2m wide with a 50cm ditch in between for watering and walking. its nice to put a peice of wood across the ditch and sit there to weed by hand, saves the back. deeper ditches are better IMO, and weeds/debris can get thrown in them, making them slow composters. everytime water runs through its like a like fertilization, which takes its deeper down causing deeper/stronger roots. i love the system persoanlly. but i wouldnt use it for veggies. Cactus works wonders, but i think the biggest issue is going to be moisture and rot. maybe avoided by cutting a circle out, snstead of an X, then filling around the cactu stem with rock to avoid mold and weeds around the plant.

[Philocacti]

Kada you're back

You just made my day