I plan to make a new slightly raised bed in my large area of lawn. I am not exactly sure how deep it will be or how big. I am ordering 7 yards of planting mix from the nursery and I will use rocks to for the border. I may add bags of topsoil and compost if I think the seven yards is not enough. Originally when I had a landscaping company give me a quote to make it they insisted the lawn had to be removed there.

Can anyone tell me why? Wouldn't the dirt on top of it just kill it? Could I at least cut a corner and just use something like Roundup and kill the grass?

I'd remove the sod/lawn/grass in the area before doing anything else, then mark out the area of the bed and lay the rock border. I guess you could lay flattened cardboard boxes on top of the grass which would possibly smother it, then add your soil, compost etc. and plants but if you just dump the compost on top of the grass, depending on the type of grass and depth of the bed you could possibly have the grass finding it's way to the surface which would just cause a lot more work. I'd remove the grass in the area first but that's just my way. Hopefully others will pop in with suggestions.

Part of my conundrum is that the 7 yards of dirt will determine the size of the bed! I have no idea how big that will be.

So, are you having the soil delivered and just dumped in the space where you want the raised bed, and building your border after the company dumps the soil? You could always spread any "extra" soil around as fill or find a place out of the way (perhaps behind a shed etc.) to dump the leftover. It's been awhile since we had topsoil, red sand, mulch delivered for us to play with but if I'm remembering correctly, your 7 yards of topsoil is probably going to be at least 5 or 6 large wheelbarrows full!

When I made a very large bed in my side lot, I sprayed it with round up. Then I laid my stone. Then I covered the whole thing with a thick layer of straw. Then I planted my flowers. (daylilies and iris mostly). I did not have to add any soil because what was there was pretty good and dayliles and iris don't need amazing dirt anyway, just pretty good was enough. This worked great for me.

plantladylin said:So, are you having the soil delivered and just dumped in the space where you want the raised bed, and building your border after the company dumps the soil?

Yes, that was the plan.

plantladylin said:It's been awhile since we had topsoil, red sand, mulch delivered for us to play with but if I'm remembering correctly, your 7 yards of topsoil is probably going to be at least 5 or 6 large wheelbarrows full!

It better be a LOT more than 6 wheelbarrows full!!

Frillylily said:When I made a very large bed in my side lot, I sprayed it with round up. Then I laid my stone. Then I covered the whole thing with a thick layer of straw. Then I planted my flowers. (daylilies and iris mostly). I did not have to add any soil because what was there was pretty good and dayliles and iris don't need amazing dirt anyway, just pretty good was enough. This worked great for me.

I need this to be a raised bed because this area gets very soppy in the spring.

Gack! I just googled what seven yards of dirt looks like!! BIG bummer.

The question then is why does it get soppy? Does the soil there stay wet or does it get wet because of a drainage issue? If you build it up, where will the water run off to? I put a large bed in my back yard once only to discover that the water then had no where to run out of the yard and it pooled on my lawn. So I had to take it out. The other thing is, if you do have an area for the water to run off to, simply laying the stones around it may be enough to detour the water away from the area. 7 yrds of dirt is not that much, but I guess it depends on what your idea of "much" is. That is another reason that stripping the topsoil away (which will happen if the grass is stripped) is a bad idea, you will lose dirt that way. Every inch is precious and expensive. By layering straw over the area, over the span of 3 or 4 years your soil will be improved a lot. You may also consider having the area tilled after you spray it with round up. This will loosen the soil so it will be easier for the plants to use it.

Jennifer, I've found the easiest and laziest way to make a new bed is to just take bags of topsoil and in late Summer or Fall lay them out - at least 2 bags deep where you want and whatever shape you want -. You want to leave the soil in the bags. No need to dig or remove grass. Come Spring all you have to do is remove the soil from the bags by taking a carpet knife, cutting the bags and pulling out the plastic and voila! You have a nice new weed free bed ready for planting.

Frillylily said:The question then is why does it get soppy? Does the soil there stay wet or does it get wet because of a drainage issue? If you build it up, where will the water run off to? I put a large bed in my back yard once only to discover that the water then had no where to run out of the yard and it pooled on my lawn. So I had to take it out. The other thing is, if you do have an area for the water to run off to, simply laying the stones around it may be enough to detour the water away from the area. 7 yrds of dirt is not that much, but I guess it depends on what your idea of "much" is. That is another reason that stripping the topsoil away (which will happen if the grass is stripped) is a bad idea, you will lose dirt that way. Every inch is precious and expensive. By layering straw over the area, over the span of 3 or 4 years your soil will be improved a lot. You may also consider having the area tilled after you spray it with round up. This will loosen the soil so it will be easier for the plants to use it.

We live near the bottom of a long slow hill. Every spring that area of lawn gets soppy. Just in the spring from spring thaw. I want to raise it so when I plant it my perennials overwinter ok. I don't plant to build a solid rock wall. I expect water will still be able to flow through. I had a similar situation at my last house and I built a raised bed in that area and it worked perfectly.

Thank you for mentioning the tilling. I had forgotten about that. I will do this. Now that I have a visual of what seven yards looks like, AND a very special someone has offered to help pay, I am getting 14 yards. I have a rough idea of what that will cover now so I can prepare the area before the dirt comes. But I still plant to put the rocks around after the dirt. I've done that before and I liked how it worked out. I hope I like it again

jvdubb said:Part of my conundrum is that the 7 yards of dirt will determine the size of the bed! I have no idea how big that will be.

Hi Jennifer -- a "yard" of dirt is actually a "cubic yard," which is 27 cubic feet; so 7 yards would be 189 cubic feet. If you wanted to make one planting bed that was 4 feet wide and filled with a foot of soil, you would have a bed approximately 47 feet long (a bed filled to a depth of 18 inches would be about 31 feet long).

I would opt for spraying the sod with Roundup rather than removing all of that organic material, and/or covering it with corrugated cardboard (or a thick layer of newspaper).

Hope that helps a little!

Xeramtheum said:Jennifer, I've found the easiest and laziest way to make a new bed is to just take bags of topsoil and in late Summer or Fall lay them out - at least 2 bags deep where you want and whatever shape you want -. You want to leave the soil in the bags. No need to dig or remove grass. Come Spring all you have to do is remove the soil from the bags by taking a carpet knife, cutting the bags and pulling out the plastic and voila! You have a nice new weed free bed ready for planting.

I LOVE this idea! But, I need this bed soon because I have plants that need to get in the ground. So I can't wait over winter. And also, there is no way in my neighborhood a bunch of bags of topsoil sitting out in the yard for months would fly. I would for sure have a letter from the township or even a visit from an official. I know it seems big brother, but it goes both ways. I like that they don't let people "junk up" their yards. Now, of course I wouldn't think leaving bags of top soil is junking up the yard......just like some people don't think old cars they plan to work on some day are junk either

Lol .. the fix for that is mound them with leaves or cover with burlap. But I know exactly what you mean.

Weedwhacker said:

Hi Jennifer -- a "yard" of dirt is actually a "cubic yard," which is 27 cubic feet; so 7 yards would be 189 cubic feet. If you wanted to make one planting bed that was 4 feet wide and filled with a foot of soil, you would have a bed approximately 47 feet long (a bed filled to a depth of 18 inches would be about 31 feet long).

I would opt for spraying the sod with Roundup rather than removing all of that organic material, and/or covering it with corrugated cardboard (or a thick layer of newspaper).

Hope that helps a little!

this does help! I am going to lay out a hose when I get home with what I would like the size to be. And then measure that. One foot deep would be perfect.

A cubic yard would be visually like a box 3 ft tall, 3 ft wide, and 3 ft deep of dirt.

Frillylily said:A cubic yard would be visually like a box 3 ft tall, 3 ft wide, and 3 ft deep of dirt.

I am horrrrrrribbbbble at trying to visualize measurements. I once had to testify in a court case. The defendant's attorney kept trying to get me to answer how far I thought it was to the back wall of the courtroom. He would not accept that I had NO idea. All I could tell him was that it was more than three feet! He just would not accept that I could not estimate distance.

Oh, I know what you mean; I have horrible distance perception myself.

>> near the bottom

The word "near" is key. If there is any spot lower than your bed, that is close enough that you can dig a slit trench from the lowest part of your new bed to the lowER spot that you've located, water will drip from your bed into your trench, then run down to the lower spot and leave your bed well aerated.

If the lower spot is in a neighbor's yard, console yourself that you're only helping it run off faster. It would always have gotten downhill eventually. However, you may be shifting your temporary sogginess into his temporary sogginess, depending on how well graded and drained his yard is.

The key question for both of you is where the water goes after it reaches the lowest local spot? If that spot has good drainage, all is well.

Another way to think of this is "lowering the water table quickly after a rain". If your trench exports water, the water level in soil surrounding and uphill from your trench will rapidly drop to be level with the floor of your trench. How far the rapid influence of your drainage extends depeneds on soil density. In very heavy clay, it might extend only a few feet to either side of your trench.

Even a narrow slit trench is plenty to drain anything short of a monsoon. Mowing may be easier and ankle-breaking harder if you backfill the slit trench with drainage gravel (French Drain). Or, infinitely cheaper and lighter, make the trench wide enough to hold some plastic drainage pipe (perforated, corrugated pipe, 4-6" in diameter, or you may find something smaller).

Of course, the key point to a drainage trench is that the floor of the trench needs to slope DOWN consistently. The easy way to make that exact is to dig it out roughly, then wait for a heavy rain. Puddles will show you the low spots. You can use a hoe or mattock to "spread the floor around", or a shovel to dig deeper where the trench was not deep enough.

There are also things you can do with string and stakes or a landscape level, or even a laser pointer to get a uniform grade, but I just pick a path and dig, then wait for rain.