# Year round weed issue in mulch areas



## crazysports457

I have a very large amount of mulch in my yard. I am constantly spraying round up in them trying to kill off the weeds. I have many different types of weeds at different times of the year. Even when it gets a little colder (30s at night) the weeds still are there. It is a tremendous and constant headache for me. I even put down Preen once and it didn't seem to help very much.

2 questions:
1. My mulch needs to be replenished and I was thinking of using rubber mulch. Would that be any better on keeping the weeds at bay? Is spraying round up or other herbicide a no no on rubber?

2. Is there something I can spray where the weeds are and not be worried about if it gets on the shrubs as well? Some of these weeds grow right next to or even in the small shrubs. It's nearly impossible to get those with round up w/o also killing the shrub.

Thanks much for any advice.


----------



## ionicatoms

RoundUp is a brand name which can refer to a variety of different individual products.

Spraying glyphosate on rubber mulch won't do any good; it only works on green leafy tissue.

I suggest you consider trying isoxaben for pre-emergent control of broadleaf weeds in your mulch beds. Prodiamine is ok for some grassy weeds. Carefully read the labels.


----------



## ABC123

As mulch decomposes its a perfect breading ground for seeds to germinate in the left over organic matter. Frequent low doses of a pre emergent might be needed to keep the weeds under control.


----------



## bernstem

Generally, mulch is a good weed deterrent, but you need to have it thick enough. 1.5-2 inches thick is what I aim for. If you have a lot of weeds, I have a feeling your mulch is not thick enough. You will still get breakthrough weeds or seeds blowing into the mulch and germinating, but you shouldn't be constantly spraying for weeds.

I would not recommend rubber mulch. It will be nearly impossible to remove in the future without digging out the garden bed and it provides no benefits to the soil. The only upside is that it lasts forever which is also a downside. Eventually you will get weeds growing in the rubber mulch as leaves, grass clippings, and other lawn debris mixes with the mulch and allows for seed germination.


----------



## Mightyquinn

I have to disagree with @bernstem on the rubber mulch. I have had it for over 5 years now and absolutely love it. It's so nice not having to replace mulch every year and it looks great and doesn't fade. Some weeds still get in but those are the thinner spots in the mulch. You will never keep 100% of the weeds out of the beds but spraying some Pre emergent a few times a year like mentioned earlier will help a lot and you can hand pull the few weeds you do get. I think rubber mulch is a personal choice and there are pro's and con's to both, I chose it for the lower maintenance aspect as I fertilize my shrubs so I don't really care about adding OM to the flower beds.


----------



## Deadlawn

I concur with @bernstem . Artificial mulches or "weed barriers" are a pain. I moved into a house with this stuff in part of the yard. Nearby tree roots have penetrated it so it is impossible to remove.


----------



## stuartmccall

For grass weeds look at Fusilade; for broadleaved weeds look at Gallery (isoxaben). 8 months control at 750g/Ha


----------



## Jeff_MI84

@Mightyquinn if using Dimension for a pre-emergent, what would be a good dose for flower beds?


----------



## Mightyquinn

Jeff_MI84 said:


> @Mightyquinn if using Dimension for a pre-emergent, what would be a good dose for flower beds?


I would still use label rate and treat it like the lawn but your fudge factor should be a little higher since most plants in the flower beds will have deeper roots. Just be sure to water it in after applying to make sure it makes it's way down to the soil through whatever ground cover (mulch) you might have.


----------



## Jeff_MI84

@Mightyquinn thank you. I have triple shredded mulch and still get prickly weeds that pop thru.


----------



## Deadlawn

Jeff_MI84 said:


> @Mightyquinn thank you. I have triple shredded mulch and still get prickly weeds that pop thru.


Mulch works well for preventing new weed seedlings from sprouting, but doesn't do anything to prevent perennial weeds from re-emerging.


----------



## Grizzly Adam

I have used Imazapyr/Pelargonic acid (Othro Ground Clear) with a little glyphosate mixed in to control weeds in my much beds, but I am unhappy with run-off causing deadspots near uneven beds. I thinking that a pre-emergent would be a much better way to go, and then just spot treat with glyphosate as problems emerge.


----------



## Jeff_MI84

@Deadlawn I gotcha. There's only three spots I have perennial weeds that pop up the same spots.


----------



## Grizzly Adam

Jeff_MI84 said:


> @Deadlawn I gotcha. There's only three spots I have perennial weeds that pop up the same spots.


A Iowa State expert on Talk of Iowa's horticulture Friday program has recommended using a foam paint brush to apply concentrated glyphosate to the foliage of problem plants like these.


----------



## Jeff_MI84

@Grizzly Adam I'm going to try that. Thanks for the tip.


----------



## Bombers

I just use my lawn pre-emergent plan (prodiamine, simazine, specticle flo) for mulch beds, tree rings, gravel beds as I'm spraying the turf. Most of these pre-em are relabeled for different industries and are use in tree farms and such. As long as you aren't planting bulbs/seeds and your shrubs are established, it should be fine.


----------



## Phids

crazysports457 said:


> 2 questions:
> 1. My mulch needs to be replenished and I was thinking of using rubber mulch. Would that be any better on keeping the weeds at bay? Is spraying round up or other herbicide a no no on rubber?


An issue with rubber mulch it that it leaches heavy metals into the soil over time. Therefore, you could have an excess of zinc, as well as chromium or cadmium, in your soil, which could harm shrubs. You really want to avoid this around gardens you grow food in.


----------



## StormTrooper86

I have rubber mulch in my beds and I love it. I got tired of refreshing wood mulch and decided to go with rubber mulch about 7-8 years ago. It looks great but it won't prevent weeds from growing any better than wood mulch.

You can use any spray weed killer from the store but be careful near the plants as it will cause damage if contact is made. Best to manually pull any weeds near the plants.


----------

