Yeah, those were some I was thinking of too. Management is back to thinking about grass which will not survive under these trees. Maybe I can get them into the ferns, that was my favorite too (and I can get them for free all over the place.)

native cottoneaster. some make good hedges. and don't mind some shade. since it is a native, it would not need watering in summer. any local nurseries to give you advice on varieties? most of the oaks around my house have vinca or ivy under them as a groundcover. i've got a bamboo that grows under a 60+ foot walnut or pecan tree in some pretty good shade. very good screen. i think it is your basic golden phyllostachus (might have spelt that wrong). it is a runner, but not an aggressive one and the shade probably inhibits the running. true, bamboo likes sun better, but some types will live in shade pretty good. there is a big quercus agrifolia at the end of the bamboo hedge....so they can co-exist. the branches on your oaks start high? if the branches were low & twisty, they could screen pretty well, but maybe they are high.

You do seem to have a large property although it's not shown in the photos. I thought perhaps you could take some examples from English landscaping. More than a hundred or so years ago, the English hillside was bare and they decided to create vistas by adding trees by the hundreds. In your case, I thought perhaps you can take this idea and add lilacs in the far horizon to create a view from afar. When you've done that, you could connect your garden to the far end by making trails. You can create areas of sweeping flowers (think meadow look) Closer to your patio, you can do an extension by creating terraced gardens - meandering iris or day lilies. I didn't mean to be abrupt about trimming your maple tree. I just couldn't see the trunk of the tree and I know from many Japanese garden views that you have a great tree there. I have done bonsai before and sometimes I can't help myself and think of ways to prune trees. I like shaping trees.

I have six large white oaks in my yard and I live in the Willamette Valley in Oregon (lucky in every way). Oaks are allelopathic but certain plants in Oregon are adapted to grow near and under the trees. Ferns, hostas, heucheras all grow under Oak trees naturally in Oregon. The trees are very sensitive to water especially along the base and mushrooms will grow on the base of the trunk as well as the root lines if irrigated/watered heavily. It is important to keep plants a distance away so that water doesn't creep onto the tree base. The roots spread equally about 3 feet down with some deeper rooting at the center - one fell in the oak grove behind my house last winter...very unusual. It is important not to disturb these roots when planting around the tree as injured roots make the tree more susceptible to disease. I have planted Astilbe, coral bells, azalias, rhododendron, Hydrangeas, heliotypes, forsythia and hellebores, coleus and begonias in addition to plants mentioned previously, under the canopy of the oaks, but I have so many I have a larger area to plant in without disturbing the trees. I am trying Japanese Anemone, but it is poisonous so it requires more care to assure animals (dogs, cats) don't get into it. These plants do well in dappled shade under the oaks rather than total shade. I try to supplement my soil with mulch every year. I carefully cultivate by hand the 7 foot by 45 foot garden under my trees with a special rake to break up the soil, add in commercial mulch and organic soil by hand and use a drip watering system with small water lines going to the base of each plant to prevent over watering. The first year is the worst, it gets better as the soil gets more an more conditioned, especially because my soil is a bit "clay" like. Hope this was helpful.