What to plant in a tricky area
I might be chasing a unicorn here, but I'll ask anyways! I'm looking for a colorful perennial to plant in a tricky area which I'll try to describe as thoroughly as possible. I live in St. Catharines Ontario (Southern), which I believe is zone 5-6, depending on what weather zone map you look at. The area I'm looking to plant is on the west side of a long needled, soft pine tree. Therefore, I believe the soil is pretty acidic due to all the fallen pine needles. It is shaded until about 1 pm, then gets sun until about 6-7 pm when the area then gets shaded again by a neighboring maple tree, meaning it gets about 5-6 hours of afternoon sun. The previous homeowner before us had some fountain grasses and hostas there and while they came back up every year, never did great and kind of just barely showed up. I really like the look of Speedwell, Salvia/Russian Sage with the way they form tall, tubular spikes of color, which I would like to have as the back border, but I don't know if any of those would thrive in those conditions. I then would want to plant some shorter perennials in front of those to add even more color and pop to the area. Any suggestions would be greatly appreciated, even if I have to switch gears and plant annuals each year if there aren't any perennials that meet my needs/wants. Thanks!
Russian Sage is a possibility but you may not have the same vibrancy that you would out of a one that is planted in full sun. They prefer to have well draining soil and do fine with some acidity. Speedwell is super versatile, that would be an excellent choice as long as you have good drainage.
You actually do have a good amount of options. Here are a few ideas for you; Dianthus, Heuchera, Dicentra - all shorter, acid loving, zone 5 and up perennials that I think would look excellent in front of Speedwell or Russian Sage. I'm attaching a few links for you to look through and see if any other options would suit you best.
Here is a link on cold weather plants;
This link is for acidic plants;
There are a ton of options out there, hope you find what you are looking for!