If it is deep/constant shade you can't grow St Augustine there. If it is getting some sun or dappled sunlight then the best thing to do is cut your grass as tall as your lawnmower can go. You can also try trimming some branches on your tree but if it is an old mature tree and you don't know what you are doing you will possibly just end up injuring the tree.

If you do get St A grass to grow there be sure to rake the leaves up cause it kills the grass. My next door neighbor's tree hangs over my yard and I was told that the leaves are not good for grass. Before I found this out I had a hard time to get the grass to grow good and healthy. I just raked them up this week, what a pain.

Barb

I don't see the point in raking the leaves unless it is 2 feet deep of leaves. Consistent mowing with mulching mower will do the trick. It also improves the soil and feed earthworms.

Mowing high at like 4 inches will greatly help as long as there are sufficient sunlight. You might have to hire certified arborist to cut the large branches down properly without harming the tree.

I was told that Live Oak leaves have to much acid in them and they are tough leaves that do not break down easy so this chokes the grass.
All I know is that now I have healthier grass thanks to advise from a good source.
Four years ago I had nothing but dirt and weeds.

No. It has nothing to do with them being too much acid. That has been proven wrong many times. Probably a combination of things.

Too many leaves that would take nitrogen away from the grass to help break down leaves making it harder for grass to grow. In that case applying extra dose of organic fertilizer like soybean meal would help.
Not enough microbes in the soil to break them down. See organic fertilizer and maybe compost to speed up the decompostion. Someone mentioned having great luck with cotton bur compost. Occasional spraying with molasses will help some. Trees rely on leaves to support their health so it's usually bad idea to rake away leaves.

I wouldn't bother to try....the grass may "survive" but will never grow thick and healthy, so there would be no point in this type of lawn....but, to each his own.
molly

Why bother? I sure wish my next door neighbor would take the time to limb up his trees to let sun in to grow grass but he wouldn't.
I have the daunting task of cleaning up the dirt that comes from his yard that ends up in front of our driveway and when it rains it's a muddy mess if I don't keep up the cleaning regiment. When it rains a lot I end up having to use the hose to wash the dirt away.
Ok I had my gripe.

BTW I only use organic products on my lawn and it has taken three times as long to get that area like the rest of my yard. Most of the yard is like a thick carpet of beautiful lush lawn.

Barb-

I know of a guy with little sunlight and he told me he's having good success with zoysia grass called Shadow Turf. Might be worth a try if you're interested. My gripe is that they sell in plugs and they are expensive! Marshall Grain supposedly sells them if you can afford them. 72 plugs for 89 dollars! They would eventually fill in over time. Of course, it would look funny with st augustine so I don't know.

Barb, as you said "I sure wish my next door neighbor would take the time to limb up his trees to let sun in to grow grass but he wouldn't". Well, neither will mine....so I don't bother trying to grow SA in the shady areas. The problem has gotten worse as the trees have matured over the 10+ years I have been here. Even if my neighbor leaves, or dies, the trees will remain. I didn't mean to dismiss your problem, or to suggest not bothering to beautify your lawn. My alternate solution was to put in a deck in that area, but I know that is not feasible in all circumstances or for everyone. I was just commenting on my own experience of 42 years of gardening and owning a nursery/landscape business. Sorry if I upset you with my comment.
Molly

I am not having any trouble with my grass NOW. I trimmed my side of the neighbors tree so I get sun, I keep the leaves raked and I add organic fertilizer.

I'm trying to help the person that wrote the thread how to get his or her grass to grow. AND everyone seems to think I'm wrong in what I'm doing or how I'm stating what I am telling this person is wrong.

I know what I'm talking about cause I had bermuda grass in my back yard and over time I've taken plugs from the front yard and placed it through out my back yard and it has nearly filled in and I have a huge back yard to fill in.

This is the best time of year to lay ST. A Grass and keep it watered good for two weeks and after that keep it water till it fills in. The other time to lay the grass is in the fall. I did a test in my back yard. I put the st. a grass plugs in covered lightly with leaves watered it reg. by spring time it started spreading. Now that part of the back yard is filled with at. a grass all with plugs. I takes time, it took this area two years.

What ground cover or shade plants would you recommend under the live oaks ?

If your grass can't get the sun it craves, then make absolutely sure it has everything else. The soil should be ideal, consider composting in the spring and correctly watering in the summer.

I've seen nice St. A. growing in shady areas of mine and my neighbors houses..

Good luck!

Under my very large shade trees I have turk's cap, Texas gold columbine, autumn ferns, japanese holly ferns, large leaf purple oxalis, Japanese painted ferns, a blue bird hydrangea (in good soil), a couple of variegated hydrangeas that don't bloom much but I keep for the white/green variegation, cast iron plant, pigeonberry, leatherleaf mahonia, summer snowflakes, toadlilies.
For groundcover you could do liriope, dwarf mondo grass. I like a variety of things that bloom or show off in different seasons and that are good for wildlife. The leatherleaf mahonias are for the berries for the mockingbirds, the turks cap for hummingbirds, pigeonberry for the doves, female yaupon hollies for the berries the Cedar Waxwings love. It's fun to watch the birds move through garden looking for bugs. So much more satisfying than just grass.

I have a large area prone to erosion under a huge Arizona ash, under which is complete shade. I needed something to fill in fairly quickly. I've got Kimberly Queen Fern (I think that's it). It borders on invasive the second year, but I need it to be there. It doesn't mind a little standing water, loves the shade, and just leaving the leaves there to rot works just fine as far as feeding it. If we go through a long dry spell, I water a little bit (I run a sprinkler for a hour every other week), but that's it. It's not that hard to control, either--just dig up or pull. I got mine pulled up from a friend's garden, not even in dirt and in a five gallon bucket that sat out for two days. I put down twenty five "plugs" and now I'd estimate the crowd at about 150 ferns.

I've also had what I think is called mondo grass under there. It's the common variety, came with the house (I don't care for it, so I pulled most of it up.), but was thick and lush and happy. In the shade, it's very dark, almost black.

Caladiums are fun in shade, but I have to either dig them up or replant every year, as they rot down here in 9.

My other ground cover is an undesirable....Indian strawberry...I swear that stuff will take over the world.

I do have some Turk's Cap, Inland Sea Oats, Columbine, and Pigeonberry under some of my large Live Oaks. However; when I took a class several years ago at the Wildflower Center, the teacher recommended that there be no plants or grass under Live Oaks. She said the trees are much healthier that way.

I have think healthy st.a under my live oak.

I water well and that's about it. We trim the tree about once every few years.

On the other side of the yard there is another Oak...not a live oak and the grass is horrible.

Hopefully the trimming we gave it last year will help.