I don't know anything much about any of the primroses that Vetivert8 talks about, but the ones I grow are pretty much a one season type of plant, and a fairly short season at that. I am not sure if that is true about the polyanthus etc., but it is something that you might want to consider. I grow the kinds of primula that like moist soil, such as P. bulleyana, beesiana, x bulleesiana, pubescens, etc. since the lower part of my yard is quite wet. Most of these (exception is pubescens) grow somewhat taller than the under 18 inches you are looking for and look best in masses. They also have a fairly early summer bloom time and are done in a couple of weeks. If the soil is wet enough they do keep decent looking leaves for most of the rest of the season, but tend to look dreadful in droughts. They are very pretty for a short time in early summer along the wet pathway, but need to be interplanted with other later blooming plants. Have you considered any of the short perennial geraniums, such as Biokovo or Carmina (x cantabrigiense), or the very short Grayleaf (cinereum), 6-10 inches or any of the sanguineums, mostly 12-15 inches tall? They make great underplantings, very nice foliage, and like the light shade of taller perennials. In zone 4 you can use many part shade plants this way. Other possibilities would be heucheras, tiarellas, heucherellas, small hostas, lamiums, many sedges (carex evergold is a beauty) & Ladies Mantle (there's even a dwarf LM ( A. erythropoda), if A. mollis is too big). You also mentioned Sweet Williams. These are not true perennials, but sometimes act perennial in my yard. I sometimes use them as edgers, but they have a tendancy for only some of them to return each year, which can be frustrating. I have had much better luck with dianthus gratianopolitanus, which forms bluish evergreen mats of foliage. Firewitch (2006 perennial plant of the year) is one that has proved very hardy for me, even in my wet clay. It has hot pink flowers, and will do some rebloom even in a short season. Another possibility for full sun is the coreopsis family. Many of them are quite short, some fairly short lived perennials, but heavy bloomers while you have them, mostly yellows, but some pinks. They make great filler plants and the common yellow ones can perk up a lot of otherwise drab one-color beds with a nice spot of yellow. I also like to use annual coreopsis seed in pots (yellow with red markings, and especially the short mahogany colored ones) - they are quick to sprout and quick to bloom and very cheap as well. If you have dry spots, you might also try some of the short Iris. Dwarf bearded iris have pretty, fairly large flowers, and quite short foliage, with lots of color choices. I use them mostly for foliage contrast, but the flowers are also lovely. I also use Iris pallida (mid-size) in semi-shady areas for the creamy variegated foliage, although I get some bloom as well. There are also lots of short sedums which like it a bit dry and work well around lilies and other bulbs, or other plants that prefer to be dry. These are mostly spreaders, can be easily expanded by cuttings, come in a variety of foliage colors & even have some nice seasonal bloom as a bonus. Lamb's Ear is another short underplanting possibility. BTW, it looks great with Firewitch and any purple, red, or black foliaged plants.

I grew hosta from seed I harvested from my own plants last year just to see what would happen. I sowed them June 20 and they sprouted, grew and kept growing right up 'til December when they went dormant for the winter. I added a little water to the pots in March and by early April the little sprouts were up again. So far this year they're going gangbusters. I also winter sowed hosta seeds and those are up as well which proves they don't need cold stratification to germinate. If it's any comfort, I harvested seeds from my heuchera and so far have no sprouts from them in the winter sown milk jug. I keep checking it and so far, nada. I'm convinced they will eventually sprout so I'm not giving up. From what I can see this first year of WS is the shade plants tend to be slower growers than the sun lovers. I've got lady's mantle sprouts but they're SO tiny. Same with astilbe--they're not even a quarter inch tall so far even though they have at least one true leaf. Looks like we need to have more patience for these. I'm going to harvest hosta seed later this year so email me if you'd like me to set aside some seeds for you. Eileen

Very pretty Christine. I love primroses, but can't grow them here. The bleeding heart and the camellia are lovely. kay

Check out Primrose Path Nursery. They are located in my State. I had problems with survival. I have very low survival with most of Terra Nova creations. You do not have to buy from them but at least when you see the ones that Primrose Path has created you know they have been tested under the cold, snow, conditions. http://www.theprimrosepath.com/listings/heuchera1.htm The other thing you can look for is if they say it is a Villosa. I have good luck with those. Next your planting conditions. Forget thinking they will survive in clay. Sun for 4 hours morning sun is better. I dig the area and removed all the clay soil down to at least 10". I then I put down pea gravel and on top of that 2" of compost. If you do not have compost use a high quality potting soil with fert. Then the Herc then compost on top. This will give you good soil and drainage. This what helped me have survivals. I lost so many I was ready to not buy another Herc I did not care how pretty they were. Here is a link that might be useful: Primrose Path Nursery