Lisa,

In time, one Oakleaf will cover a pretty large area, but they can be slow starters so I would buy the largest ones I could find if I were you. On the other hand, you could save a lot of money if, unlike me, you have the patience to start small. The average non-dwarf oakleaf will get to be around 7x6(?) wider than tall and some like Alice will get larger than that(12ft?). Don't know if they will reach full size potential in your zone 6 as you may suffer some winter dieback each year. Snowqueen is one that I am fond of. She supposedly does better than most in colder climates, has a strong growth habit and also tends to hold her blooms more upright than some of the others.
Dappled sunlight should be ok as that is their natural environment. Good drainage is more important though as Oakleafs need moisture but will not tolorate wet feet. Good luck...yg

Dappled sunlight sounds like a very suitable location, but only you can be the judge as to how much shade this situation actually generates. Oakleafs can take quite a lot of shade but flowering may be reduced if the shade is very heavy and you will not generate good fall color without some sunlight. They will still make a handsome, bold foliaged plant in more shade than sun, but you may not be encouraging some of their best features in too much shade.

Dappled or filtered shade is generally cast by deciduous trees without heavy canopies, so that the light filters down through a pattern of branches and foliage, offering periods of bright or even direct sunlight through the course of the day. This is quite a bit different than shade cast by evergreens, structures or even dense canopied deciduous trees and is generally to the liking of most hydrangeas.

I have one in similar conditions, dappled shade, no direct sun, and it's doing pretty good. : ) July and August are dry here and I have to give it some water but nearly everything I plant in that area needs extra water. My tree roots are greedy.
Some shrubs will LIVE in shadey areas around tree roots but don't bloom very well. My oakleaf hydrangea HAS been blooming but it's only been there about three years so it's too soon to say whether it will bloom as well as one in a little more sun. So far I'm pleased.

In z6 dieback would be a less likely event for oakleaf, though amount of sun will grossly effect blooming ability and fall coloration.
If space is not of consideration and you would like to see different forms and textures of foliage, you may plant mix of oakleaf, cutleaf sambucus, bottlebrush buckeye and some evergreens (rhododendrons and cherry laurels).
This way you'll create an all season interest back border.

I can say have seen the differance of shade versis sun.I got my cuttings from one growing in almost total shade.it mostly flowers on the older wood thats higher up and outer branches.has just slight coloring in fall. My 3 cuttings growing 2 get more sun& have alot of coloring on their leaves& have a second one thats grown mostly shade maybe a 2 hour period of dappled shade and is hardly any coloring& looks very similar to original grown in very similar conditions.I watered mine regular,but we've had a dry year.

My oakleafs don't get much sun (I'd peg it at about 3-4 hours total, half of which is morning, half of which is later evening sun), and while they are healthy foliage-wise, I don't get a lot of blooms, just a handful on each bush. I grow them in this location anyway because I love the foliage effect, but admittedly they would grow faster/become larger and flower more and have better fall color in the sun. But hey, I have to deal with the conditions I have, not the conditions I wish I had. :)

I have a large Oakleaf that needs to be cut back to about half it's size. When would be the best time to do that?

Thanks, folks, for this discussion! I have been trying to grow hydrangeas for the past 2 years and have been somewhat foiled by--at max--2 hours of noonday sun (it killed, I think, 2 Endless Summer hydrangeas). I planted an oakleaf, "Snow Queen," in the back of my garden rather near to a poplar tree. I'm watering well b/c of the dry soil tendency (near a big tree), but your discussion of shade/dappled shade/oakleafs was so helpful. Certainly more helpful than other material/info online & at nurseries (unless your nursery grower has your own conditions). Thanks again! I wish I could grow more hydrangeas since I LOVE the old world look that they have.

I have a split-level home where the upper floor extends over the lower floor by about 30 inches. This is on the north side of the house. I have oakleafs growing under the overhang as a foundation planting. There are two large water oaks in front of them. They get about 3 or 4 hours of dapppled and indirect sunlight in the summer with heavy shade the rest of the day. They grow and bloom like crazy. People often comment about the healthy bushes, lots of big blooms and sweet fragrance. They don't get much direct moisture. I dug these at a local plant rescue. The northen exposure is the similar to where they grow in nature in my area. Now, I have a Snowflake double which is in full sun and does extremely well.

Victor48, you should leave heavy pruning for a time when the plant is dormant. Do note that some people recommend that heavy pruning be done in thirds: prune the 1/3 oldest stems a year for three years.

But you do what you need to do. Be aware that this will affect flower production since oakleafs have started to develop flower buds for next spring.

If you were planning to prune much less than 1/2 the plant, another good time would be right after the shrub has bloomed. The advantage is that you do not loose any flower buds for next spring.

Luis

A standard oakleaf gets to be a pretty big shrub - 8'x8' is not uncommon and I've seen larger. If this is too big for your location, rather than pruning it severely which I am very reluctant to recommend, consider moving it to a more suitable location where it can grow without frequent pruning or replace it with a dwarf form. These still have the ability to reach 4'x4' in time.

A well-sited mature oakleaf hydrangea is a stunning plant in all seasons and pruning to reduce or maintain at a smaller size can be an unfortunate limitation to its growth habit and appearance.