I love geraniums! They are virtually indestructible! I can't seem to kill them!. They come in so many different colors and fragrances. Mine grow to about 3ft across, about 2-3ft high. I like bulbs too. I have a few daffodils and hyacinths. The hyacinths are very fragrant!
THIS TIME AROUND
I LOVE daffodils - inexpensive - they look pretty when planted together (rather than six-eight inches apart) and will multiply as the years pass while other bulbs are less prolific as time goes by. Plus, they're an early bloomer, so it's nice to have some color as winter is fading away. I like the little tete a tete ones that bloom very early and have multiple blooms on the stems, as well as the more traditional varieties.
I did a "memorial garden" in the front of my home for one pet and in my back yard for another ... ... and then kept on going as I enjoyed it more and more ... now have more than I can handle! A pretty shrub that has a very fast growth rate is a dappled willow - very pretty light green/cream/pink leaves to start the spring. Daisies will bloom in the late spring right on into the late summer. A burning bush will be just green all year until the fall and then be a blaze of small red leaves for a few larger ideas. If you're wanting it to be peaceful, maybe try all greens and whites, or something along those lines, too... GOOD LUCK!
Pansies are insane- not sure where you are from. I bought 2 sets of pansie for like 2 freaking dollars at home depot. At first I thought they were dying but I kept on watering them daily when I read on some site it's virtually impossible to overwater a plant. Now they are in HUGE bunches and put my other flowers to SHAME.
I'm actually going to the store today to get some more mulch since weeds are starting to poke out now. BOO WEEDS. I might get some more fertilizer too.
I adore Foxgloves ... they are a bit on the pricey side but they are beautiful ... mine are white ... but beware they SPREAD like crazy. I have them all around my pond area but every year I give some away to people because I have MORE than I need. They would make great fillers though too. They only require minimal care ... they thrive best in morning sun/shade ... but my pond is in direct sun and I haven't had a problem at all with them.
I am another geranium fan. Practically indestructible. Anther favorite is Iris. But it all depends on where you live and the weather in your area. Check at your local nursery, they are usually glad to make suggestions, you don't have to buy everything they suggest. I prefer perennials so I don't have to replant every year. Let us know what you choose. Good luck ! PS One of my all time favorites are Lilacs, but I live in California , they don't do too well here as they like cold winters. They may grow too big for your memorial garden, though.