Increase the ground level around my ornamental grasses

5 years ago

Hi all,

This is a bit of a dumb question, but I know someone here can help! I have a row of ornamental grasses in my backyard that create a privacy wall along my back fence. There are about 30 of them that span 100ft. The left 15 are in good health, but the right 15 never do very well. The reason they don't do well is that this area is a bit of a low point in my yard. After the first 15 ornamental grasses, there is a slope downward about 6". It then levels out, but it's definitely a low point. So water tends to flow here and then it can stay wet in the Spring. This causes the grasses to never quite grow as well and leads to more weeds for those 15 grasses.

To fix this, I went ahead and spread some dirt around all 15 of the grasses on the right so that it is no longer a low area and the water flows towards my yard and into an easement. This seemed to help as the area stays dry and we don't get any pooling of water when it rains hard. My plan is to go back over with mulch this Fall.

My concern though is that by raising the dirt around the ornamental grasses, I may have unintentionally causes water to get trapped inside the ornamental grasses. Normally when you plant a bush, you want the bush to be a bit higher than the surrounding dirt. That way it drains properly and the root ball isn't covered. In this case with the ornamental grasses, it's a bit of the opposite of what you would normally do. The ornamental grasses are a bit lower than the dirt around it.

You can see here what I'm referring to. Here I've just added dirt all around the ornamental grasses so that the water will now flow towards my yard and away from the row of grasses. I'm then going to add some mulch over this.

My concern is just that I'm going to trap too much water now in the grasses as the ground around it is now higher. Is there anything else I could do? I'm sure the best way would be to dig all of the grasses up, level the area, and then replant them. But honestly, that's just way too much work for me right now. It took me about 6 hours to move and replant 3 of them already.

Is it possible to just add a thin layer of dirt over the ornamental grasses when I cut them back in the winter? Would it grow back through the dirt that is over it? Or would that smother the grasses depending on the depth?

Thanks!

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Comments (5)

John D Zn6a PIT Pa
5 years ago
I/m not sure with ornamental grasses. But grasses in general won't be harmed by adding small amounts of dirt. The golf industry does this regularly adding sand to clay soil. I don't know that in areas with sandy soil that they add clay. This also happens during floods.

I've covered an entire lawn with a mixture of 4 parts mushroom compost and one part sand. I did this a half to an inch deep. You wouldn't believe how the sand changes the way this changes the tilth of mushroom compost. With the sand in it it spreads so nicely. If you mow your lawn without bagging out the clippings you're slowly building up the sod.
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Yardvaark
5 years ago
I think you could get away with adding soil over the crown, but NOT do at the beginning of the dormant season. Wait until Spring when they are full of vigor and ready to bust out into rapid growth.
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Eric
Original Author
5 years ago
Thanks all this was very helpful! @Yardvaark that's a good idea to do it in the Spring. What is the max you would go? Maybe just an inch?
ken_adrian Adrian MI cold Z5
5 years ago
have we seen this full lay out a while back with better pix??? .. you got like a million of them along the property line ...

the easy answer would be to dig them up.. and just relevel the whole ... unless of course.. there are the million of them ...

even if you just start on one end.. and just take a year to do it ....

also ... this isnt going to kill them in a short period of time ... if you see a decline in some plants ... then just dig them up ... reset them ... and they will recover.. these arent foo foo plants ...

lastly.. if you have a row of many... just try different depths.. and see what happens ... and react accordingly ... you might be surprised at how far you can go ... but you arent going to get definitive answers in advance.. you are probably dabbling on state of the art.. so wing it ....

and if some are lost.. its not like you couldnt propagate a half a million more in one season.. they are grasses ...

dont make this harder than it need be .. the theory i mean.. the work will be back breaking any way you do it.. slinging sand around isnt light labor .. so you may as well do it right the first time.. so you dont have to do it again ...

there is no way around some hard labor here ...

if you do experiment.. keep us posted ... you will be the definitive expert on this issue.. by the time you are done ....

ken
Richard Brennan
5 years ago
last modified: 5 years ago
Yes - this is a super easy fix because grasses by nature are hardy and adaptable. Just add dirt and mulch in the fall. They will eventually put roots in to that extra soil.

Grasses are the opposite of sensitive bushes like roses that need the crown at an exact level and an inch higher or lower can harm the plant. Grasses just go with the flow. That's why they are the first plant to come in and reclaim damaged or poor soil. You even see them springing up on the beach.