If a seed packet says sun/part shade it usually means that it likes full sun, but will do just fine in part shade. Of course that "part shade" is a gradient that starts at less than 6 hours of sun and gets less and less till you get down to less than 2 hours of direct sun which would be considered pretty much full shade. I would try to keep most sun/part shade plants in the upper range of the light gradient, but there are always those that will surprise you in more-shady locations. How many hours of sun does 1/2 sun mean to you? Is your shade solid or dappled? What time of day? Those are some questions that will affect what plants to suggest.

Of course, part-sun in Texas and part-sun in NE is completely different animals. Beside the point, part-sun in NH and part-sun in CT is different...and part-sun in coastal CT is different than a part-sun in a Litchfield county, CT...and part-sun in one part of the yard is different in another.

You need to be more specific about your particular situation and zone.
Just to give you an example: I'm in 6b, coastal CT. I have two clumps of phlox 'David', they are 5' away from each other and both are technicaly in part-sun.
One, which is in a dappled shade whole day blooming once, in late August-early September. Another, which have a 3.5 hours of direct western exposure and in a fairly dense shade all other time blooms in very early August and if deadheaded again in October.
So much for the 'generic' part-shade.:-))

Thank you both for responding. I live in Brookline, MA. Most of my garden areas are protected by leaves from surrounding trees so they all get shade at different times during the day. The only area that gets full sun (solidly more than 6 hours per day) is my front lawn. I grow vegetables in containers on the lawn which did OK this summer. The other areas with gardens in the summer get at most only around 4 hours of direct sun, 6 hours of indirect sun (through the leaves) and the remainder in shade. The sun on the gardens and lawn is in the afternoon.

I'll be looking at David phylox - that sounds like a good start. I tried so many different perennials this spring/summer, mostly part sun/part shade, but most of them didn't make it (mostly because of my mistakes and partly the weather). The one I was SURE of was Columbine (McKanna's Giant and two others kinds of Columbine). I've seen several internet places that say Columbine does well in shade. Seeds started inside, outside, a plant I was fortunate to get at a swap and a plant from a friend. No luck. But I haven't given up!

Thank you so much for your help. I'll know a lot more next year and plan to Winter Sow in December. Starting with the right sun/shade seeds will be a huge benefit. I appreciate your help.

I did some research on the Phlox (David) and your suggestion was perfect. Although most of the internet information said anywhere from Full Sun to Sun/Partial shade to Sun/Shade (aaaaggggghhhh!) the consensus was very favorable regarding the blooming time, fragrance, hardiness, etc. Also, someone on the GF Exchange from CT (my home state too, Ego45 and Cloud 9 - born in Southington, grew up in Wethersfield) has it to trade. I take the information the internet has to offer but I think you guys are best because of your enthusiasm, wisdom and experience. Thanks.

Zahzeen, I think your columbine should have done well in shade/part shade. Are you sure it was the light conditions and not anything else that affected it? Moisture? Soil?

The part shade/part sun thing can be tricky. Your best bet is probably just to experiment. But do remember that your soil and the moisture conditions, and even things like wind exposure, can all play into a plant's survival.

Good luck, keep trying, and don't give up!
:)
Dee

I find columbine does best when directly sowed where I want it to grow. Some other plants I grow in part shade in the types of conditions you describe with high, dappled shade and a few hours of sun include some clematis (vines - not all will do well in shade, so Google clematis for shade or go to Clematis on the Web and browse), hosta (many have nice flowers in lavender or white as well as lovely leaves), astilbe, siberian iris, and Actea (often listed as Cimicifuga, its old name.) Think about interesting and varied leaves (either color, shape or size) as well as flowers. For instance, the Actea/Cimicifuga has TALL wands of white to pale pink flowers now, but much of the season its interest is provided by somewhat ferny-looking dark purple leaves. (It also can be bought with green leaves.) You could grow climbing hydrangea up a large tree trunk - it doesn't seem to hurt the trees at all. You may be able to get a rooted cutting at a plant swap since it seems to root reasonably easily. Hydrangeas are woody vines or shrubs, not perennials, but the shrubby hydrangea paniculata and arborescens varieties, like Annabelle, Little Lamb, Pinky Winky, Pink Diamond, Limelight, etc. and the hardy Hydrangea macrophyllas like All Summer Beauty and Endless Summer bloom for me quite well all summer and are fully hardy here on the border of zone 4. They will tolerate quite a bit of shade and as long as they get a few hours of sun I've found that they will bloom.

I'll also suggest that you visit good local nurseries or ornamental gardens or an arboretum periodically through the spring, summer and fall to see what is blooming and/or looking nice in their shade sections. Take notes, maybe buy some plants at the fall sales if your budget will allow and you have someplace to put them.

Here is a link that might be useful: Clematis on the Web

Check out heuchera/heucherellas. They now come with foliage in a wide variety of shades. They do bloom, but foliage keeps them interesting all season.

I don't winter sow, but it seems like an inexpensive way to experiment. Try seeds listed for partial shade, try them in several different locations and see what works out where.

Thanks for the suggestions. This gives me a good start on what to look for.