Oak wilt is a real problem, but primarily in a woodland setting where root grafts spread the disease from one tree to another. It can be nasty and I've had to remove many infected trees in the woods. However, I wouldn't let it keep me from planting red oaks. Its unlikely you'll have a problem if planted in an open area, prune appropriately, and avoid wounds. This from the WI DNR website regarding OW spread: Underground: Most oak wilt moves from diseased trees to healthy trees through roots that have become interconnected (root grafts). Most root grafts form between oaks of the same species; red oak roots graft more commonly than do white oak roots, and grafts between red and white oaks are very rare. Overland: Some movement of oak wilt is overland via sap-feeding beetles. In the spring, fungal mats (small masses of Ceratocystis fagacearum) develop under the bark of some trees that have died from oak wilt the year before. These mats force the bark to crack open. The fungus produces a sweet odor that attracts sap-feeding beetles on the mats. The beetles then fly to healthier oaks to feed on sap flowing from fresh wounds, thus infecting healthy trees.

I don't know pin oak, but I do find it mentioned in lists of trees unsuitable for underplanting with rhododendron and azalea....it's on the list as an unsuitable associate, reasons for that grouping of trees are: too dense or fiberous rooted. Have you dug around theplanting area under your tree to see what, if any, root competition there might be? Are the lower branches drooping in form so that they exclude too much light? Sometimes these larger trees can really rob the soil of nutrients and water more than we realize...do you mulch with compost or organic plant remains? I'm growing many oriental hybrids, foetidus, macrantha in my acidic clay. About once every 12 - 18 months, I push a stick of plain blackboard chalk down in next to each plant for a slow release of lime (three sticks for a large clump). Seems to work very well, and I don't have to be concerned about changing the PH of an entire planting area and making the acid lovers unhappy.

I have a lot of oaks, but most of what I have under them is more along the line of perennials, not shrubs (but I thought oaks were *better* to plant under than other trees, because their roots were deep, not shallow...??) still_lynnski, I'm having a bit of a hard time visualizing this (I am a visual person and literally need people to draw me a picture, lol). But if this row of arborvitae and oaks is the SE boundary of your property, does that mean the sun is behind it for most of the day? So it really is quite shady then? Anyway, I do have viburnum, hydrangeas, azaleas, deutzia, fothergilla, and rhodies planted under my oaks. I might be trying kerria this year. I have carex also, but I guess that's more of a grass. I also have a quince and some forsythia, but they do get more sun. In a friend's garden, partly under oaks, but farther away from the trees themselves and therefore less root competition and more sun, we planted viburnum, clethra, itea, buttonbush, cornus alba, and ilex verticillata. But I do want to stress a few things here - it is quite bright shade, the area is very wet (which these plants like) and this is really just a big experiment in her very wet yard! So I can't give outright recommendations for these plants in your situation, but thought this might give some leads to research for further info. MG, I'm surprised to see some items on your list - lilac, mock orange, species roses - how much sun do these get under your oaks? Just curious... Still_lynnski, I think your "change of perspective" is great - it's a wonderful way to look at this area! Have fun, good luck, and keep us posted (pictures would be nice!) :) Dee

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.