View Full Version : Protecting trees during lawn renovation

05-30-2004, 09:40 PM
I've been reading all the great advice about soil prep, and it's really been valuable. But now that I'm at the point where I need to get started, I have some questions about protecting the trees while I redo the lawn.

Just bought a house in Sacramento last fall. Other than planting a few herbs, we pretty much just left the backyard as it was to see what would happen during the wet season. After an especially hard rain, we found out that our neighbors had solved their drainage problems by pitching their yards toward us. The "soil" is an extremely compact clay. In the summer, it takes a pick-axe to make a small hole for planting. So, we will need to fix the soil problems, regrade, install sprinklers, and install a drainage system in order to take whatever water does accumulate after all this out to the street.

We would like to scrape off what little grass there is, mix in compost, and then hydroseed with a drought and shade tolerant grass mix. We've just had the trees pruned and thinned out, and now pretty much all of the lawn gets direct sunlight at some point in the day. If we want to protect the trees that are here, (mulberry is shown, but there are several other trees on the lot - just can't figure out how to attach multiple pics), but would also like some lawn. When we dig up the lawn area, how far away do we need to stay from the trees in order to make sure we don't damage them?

Any other suggestions on our plan would be appreciated. We're trying to get the place ready so that we can have our wedding in the backyard next summer.

05-30-2004, 09:42 PM
Here are two other trees in the backyard.

05-30-2004, 09:44 PM
Close-up of the grass and the soil problems.

05-30-2004, 09:49 PM
Here's a pic taken after a hard rain this past winter. Witness the "great" drainage in action. One neighbor told us that the woman who lived here before us let the yard drain on its own, and it usually took a month or two. We opted for a pump, but would like to avoid that in the future.

05-30-2004, 10:04 PM
Oops, I meant to post all of this in the homeowner assistance forum. Could an admin move this thread?

05-31-2004, 04:27 AM
I'm not familiar with CA trees but generally trees have significant roots extending past the dripline of the tree (outer edge of the branches). As far as the tree goes it would prefer not to have grass planted on it's roots, but it looks like if you plan on having any lawn at all you will have to plant over the tree roots. Is it possible to import soil and build up 6-8" over the existing soil height? If you build a tree well with stone or blocks about 6' or so from the tree trunk(s) leaving the soil at the level it is now you could raise the lawn up and not damage the tree roots. You could backfill the tree well with a loose compost and soil mixture (real compost, that is) and plant flowers or shrubs and the look could be very nice. Caution should be taken not to pile any soil or mulch on the tree trunk directly, that could create future problems for the tree. If you don't address the drainage problem, you probably won't be able to keep a healthy lawn very long. Can you build a curtain or french drain between you and your neighbors? An 18"-24" deep trench just a few inches wide filled with drain rock would do the trick. Make sure it slopes away from your property or into a storm drain or sewer. If there is danger of cutting tree roots doing that I'd consider something else. Is any of this possible? Neal

05-31-2004, 05:24 AM
Thanks for the reply! I'm able to get compost in large quantities from the city for $9/cubic yard (http://www.pwsacramento.com/solidwaste/compmightymulch.html), so that's what I was planning on to bring in and add to the soil. The only concern I have about raising the soil height so much is that I wouldn't want to damage the trees by building up the area around them. But, a tree well might be a way to keep that happening. Also, the area in the back is too low, and we'll need to bring in soil and/or compost to raise that up. From what I understand, adding compost is really the only way to make this particular soil more workable. If I added sand, I fear the clay would end up even harder.

And yes, we're planning on adding a french drain for diverting water. However, I'm a little concerned about the roots of the mulberry tree in the first pic. The french drain would need to be on that side of the yard. Maybe a dry well in the back would be a better option? But, there are also trees in the back (see attached pic of tree in the right-back. There several more trees all along the fence).

I'm also starting to wonder if after ammending the soil, hydroseeding will still be the best option. Cost is a concern (and why I thought hydroseeding might be a good choice), but if it doesn't turn out well, it will have to be reseeded. Maybe sod would be a better value?

06-06-2004, 03:28 AM
Sod is a little better because it is instant cover and weed germination is limited, besides the fact you have an instant lawn. Cost is an issue as you mentioned for sure. Hydro-seeding still has to be watered just like any seed job. I believe you could seed yourself and do a fine job with a little coaching. I'll be glad to help if you want to try it. Neal

06-06-2004, 11:46 AM
If you are concerned about the roots, get someone to come in with an "air spade" to dig the trench for the french drain. The air spade won't damage the roots of the trees.