It is not so much the size of the bark chunks that determines that mulches effectiveness at deterring unwanted plant growth as it is the depth of the mulch, although very large chunks even at 4 inch depth might allow some sunlight through. I would look for bark chunks about an inch or so square.

3 inches deep is the bare minimum for weed suppression. I also recommend finding a local landscape materials place. I never buy bagged mulch. It is so much easier and cheaper to order a dump trunk load of mulch delivered.

Since I don't have a pickup truck to transport bulk mulch and my garden is 200 feet away from where the mulch can be dumped, I'd have to rent a wheelbarrow and make many back-and-forth trips between the dumping location to my garden.

That means I'm looking at bags from Home Depot, Lowes, Walmart, etc.

Please provide a picture of the bag the bark chunks comes in.

My garden measures 400 sq ft so I'll need about 60 bags of bark applied 4 inches deep. I have a wagon that will carry three 2-cu-ft bags at a time.

What's the difference between "mulch" and "bark" anyway?

Mulch is generally anything put on top of the soil to suppress weed growth and retain moisture. Bark is a specific type of mulch, of which there are many.

Which of the many images show the size of the bark nuggets that will do the best at blocking light from weeds? (I plan to apply a 3 to 4 inch layer of bark nuggets)

I think you already have your answers here. It's not so much the size of the pieces but how deep you put them down.

Keep in mind big box stores get their products regionally so they vary as far as brand and contents. They can even vary seasonally with changes in available materials (probably more with for compost than bark though).

They have people at the store who can show you what they have. Pick something you like the looks and the price of and buy it. We're probably not going to be able to help much more than this short of going to the store with you.

My reference book says that size matters. It says "The bigger the chunks of bark, the more weed control it offers" and "If weeds are a problem, use the big chunks of bark".

Your reference book was probably written by someone who has never gardened. ;-)

If you are concerned about weed suppression, placing a layer of wet newspaper or wet cardboard down before you mulch provides an extra layer of weedblock. The paper and cardboard will eventually decompose with the benefit of adding organic matter to the soil as it decomposes.

My reference book was written by a Master Gardener from the University of California Cooperative Extension Service.

My plan is to:

1. pull the existing weeds
2. apply a pre-emergent weed preventer (like Preen)
3. place a layer of cardboard on the soil
4. spread three or four inches of bark on top of the cardboard.

That may be over-kill but the ever-recurring weeds are KILLING me!

Master Gardner - doesn't surprise me.

All you need to do is number 3 and number 4. Number one and number two are unnecessary and just more work and the preen is an unnecessary expense and (chemical).

Several weeks ago, I pulled the existing weeds (mostly black medic) and planted six bareroot roses.

I then bought the Preen. Before I applied it, I asked Preen.com's customer service staff if I could immediately apply the Preen. They said "No, I should wait until the bareroot roses become "established" (i.e., when leaves and stems have formed)".

In the meantime, new black medic weeds have sprouted so I'd like to pull the new weeds and apply the Preen before laying the cardboard and the bark.

My thinking is that you'd have more light getting around the big bark pieces at a 3-4 inch depth than if you used a regular mulch at the same depth. So the bark isn't a personal style preference for you?

Of course the cardboard would completely shade out the soil and weed seeds. That's my method, cardboard and enough mulch to hide the cardboard.

My "bark" vs "regular mulch" choice is because I think bark would look better in my 400 sq ft garden beside the entry to my house.

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My apologies. The writer of my reference book is NOT a Master Gardener but is MARIANNE BINETTI who is a northwest horticultural expert: Marianne has a degree in horticulture from Washington State University and writes a syndicated gardening column that runs in over a dozen newspapers each week including the The Tacoma News Tribune and The Daily Olympian.

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Here are my questions and her responses:

gcotterl : Is it true that bigger the chunks of bark offers more weed control?

Marianne's Response… Yes the bigger chunks of bark offer more weed protection but putting newspaper under the bark layer offers even more weed blocking ability. The size of the bigger chunks should be as large as 2 to 3 inches

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gcotterl : After the newspaper decomposes, why won't the bigger -- "as large as 2 to 3 inches" -- chunks of bark mulch allow sunlight and weed-seeds to pass through to the soil causing new weeds? Why wouldn't smaller bark do a better job at blocking new weeds?

Marianne's Response… The reality is that most weeds come from above - blowing in from the air and the finer bark allows the weed seeds to sprout while the big chunks help to block weeds from below by weighting down the paper better and weed seeds from above by blocking any route for the new roots to reach the damp earth

Whether most "weeds" come from above, ie on the wind or via birds, depends. Many "weed" seeds are distributed via the wind and birds while others grow from roots already in the soil.

Larger chunks of bark will have larger spaces that may help keep "weed" seeds from germinating, but that might also allow sunlight to reach the soil. Bark fines may provide a moist environment that could allow unwanted plant seeds to germinate and grow.

Mulches help keep unwanted plant growth under control but they do not eliminate them altogether. Most of us have found that a mulched planting bed will have less of a "weed" problem then a bed that is not mulched, but that mulched bed will still have some "weeds" that will need attention.

What size bark nuggets should you buy? What do you want?

What ever size will deter weeds the best and look presentable.

My local big-box stores (i.e., Lowes, Home Depot, etc) have many kinds of mulch ranging from shredded to nuggets (mini thru large) to chunks.

For a 3-to-4-inch-thick layer, I'll need about 60 2-cu-ft bags which costs between $180 and $250 so I want to buy the correct mulch for my garden.

60 2 cuft bags? That's about 4 cuyds. I would contact a landscape supply company. It would be cheaper to have them deliver that quantity in a dumptruck.

My garden is 200 feet away from where the mulch can be dumped. If I had a pick-up truck or had the mulch delivered by a dump-truck, I'd have to get a wheelbarrow then make many back-and-forth trips between the dumping location to my garden.

But I do have a child's wagon which will carry 3 or 4 bags of mulch at a time.

wagon

Is the 200 ft that you would have to transport any mulch, dumped from a truck, the same distance that you are going to transport the bags of mulch in your wagon? If so, you could get a very generous pile of mulch delivered, and with the money you save, you could buy a wheelbarrow and a pitchfork to transport and spread the mulch. You could probably afford to put down 5"-6" of mulch, and then you'd have a wheelbarrow to use for future projects.

At the very least, buy the most inexpensive mulch, regardless of the size of the chunks. I don't think the difference in weed suppression between one size of mulch and another is significant enough to warrant spending an additional $60, which is what the range you quoted would imply. You could buy a decent wheelbarrow for $60.

Good luck. I know how irritating those blasted weeds can be.

Martha

I have never been able to find a better deal on bulk bark than I can get at Home Depot. If I watch for sales the bagged bark at HD is cheaper than the bulk stuff at the local landscape supply outlets. This time of year is usually when HD has bark sales. I haven't seen one yet this year. Alternately sign up for the HD garden club and get coupons for $5 off $50 or $10 off $100 generally during the Spring months.

Bagged bark prices seem to be unique. Just about any other type of mulch is a lot cheaper in bulk.

For a project this big I'd spring for a heavy duty wagon with inflatable tires from a farm supply. Or borrow a riding lawn tractor with a small dump trailer. But I'm kinda lazy I guess. :-]

No one in my condo development has a riding lawn tractor with a small dump trailer. Also, I can't drive a tractor on the common-area sidewalks.

A heavy duty wagon with inflatable tires costs at least $70. What would I do with the wagon after this project?

I don't know man, I'm just making suggestions that might be helpful. Only you know your situation. Take what works and leave the rest. :-]

This is the brand of bark I used to get for my flower beds (Comes in different sizes). Thank god I discovered the city wood chips and saved myself a ton of money (Tree trimmers are always looking to get rid of their chips as well, typically for free) as I now cover about a 1/4 acre of my property in them.

The larger you get the bark chunks the longer they last. Smaller pieces will break down quicker. So depending on what your going for which seems just to prevent weeds...I would go with bigger chunks (1 to 2 inches). I would also plan to go at least 5-6" in depth.

I wouldn't waste my time pulling those weeds. Squash them down with newspaper or cardboard....get said material wet and apply the bark. As long as you continually apply more bark as needed you should not have another weed problem and if you do happened to get a weed they are extremely easy to pull out.

Happy Gardening!

Jennifer

Not sure why it did not get the other pic....

I'd imagine new weeds would be more likely to grow in small-sized mulch than in larger chunks of bark.

Gary,

Your situation could be a good candidate for a new mulch mat on the market. It's made from non-woven hemp fiber. The mats weigh just 7% of the equivalent coverage in bark mulch (at 3" deep). You could easily carry the rolls the 200' to your garden. It is more expensive than bark mulch, but you may find the labor savings worth it. It's a viable alternative if you plan on putting newspaper down, and then bark on top of that.

www.woven-earth.com

Disclosure: I work for the developer of this product.