Balance is not the same as perfect symmetry. You need to choose plants that have roughly the same mass and repeat the same colors without trying for the exact same plants. It simply won't work.

Even if you choose plants that will grow in both sun and considerably shade, they won't grow the same way.

Hi there.

I feel your pain:) In our back yard off the porch I have a very similar situation. My husband planted a willow tree a few years back and it shades one little flower bed that sits off the side of the steps and does not shade the twin flower bed on the other side. Last year that drove me nuts as I had hollyhocks planted on both side and the ones on the left grew about a foot taller.

This year I'm going to transplant and give away the hollyhocks and plant the hybrid musk rose 'Grandmaster' (actually two, one on each side) in both little flower beds. My hope is that even though the one on the left will still grow more I can keep it trimmed back to match the other one. Since hybrid musk roses can tolerate more shade than other roses this might just work.

I also went after the willow tree with a chain saw this fall which was great fun.

Hope this helps.

Kate

Lacey is right about the need for balance. You need to choose sun loving plants for the sunny side and shade lovers for the shady side. It might help you to go through a couple of seed catalogs (and/or perennial and/or bulb catalogs) and make a list of things you like in two columns: one sun, one shade. Then start looking at the individual plants. Try to choose pairs of sun and shade plants that share at least one attribute, more is better: height, leaf shape or texture, overall form of the plant, bloom form, bloom color. Then arrange them "symetrically" along your front.

Just to get you started, you might plant your zinnia profusion on the far right side of the sunny side and "match" it with a similarly sized white begonia or white torenia on the far left shady side. These plants have in common: bloom color, plant form, bloom mass, and plant texture.

You could plant white Echinacea as a match with shastas (Echinaceas like part shade in my area. Check to see if this holds true for you.) These two share: bloom form, bloom color, plant height, and plant form.

Keep in mind that often, some plants might make a good match, but their mass is very different. In that situation, use more plants of the smaller one. For instance, if one plant grows 3 feet wide and the other only 12 inches wide, use 3 of the smaller plant to match up with one of the other.

And, do use reasonably sized masses of a few kinds of plants, rather than one plant each of alot of varieties. In the end, you'll have a much more attractive bed.

It will be an easier process if you start matching with your shade plants, since there are far more choices for the sunny side. Don't forget small blooming shrubs either. For instance, some of the continuous blooming hydrangeas are pretty small in stature (Forever and ever, for instance) and they enjoy shade.

And for some super wow, try to also do some matches (echoes) between your blooming plants and your permanent evergreens in the bed too.

This will take some time and thought, but then, that's what winter is for! :)

Good advice all around. I will only add that when you say "partial shade" be sure you know exactly how much sun you are actually getting in that area. Don't guess. 2 hours of direct sunlight is quite different than 4 hours and makes a difference in which plants will do well. It's easy to find plants that tolerate full-sun, whereas partial sun/shade can be tricky. It's usually a matter of trial and error.