Ask Mr. Smarty Plants

Sounds like you were very fortunate in that the previous owner of your property was a gardener. As there are literally dozens of flowers with "daisy" in their common names, we first tried to establish what your missing plant was. Since at the Lady Bird Johnson Wildflower Center we specialize in the preservation and propagation of plants native to North America, we started with our Native Plant Database. We found Erigeron annuus (eastern daisy fleabane) and Layia glandulosa (whitedaisy tidytips), pictures below, that seemed to come close to your description. Both are found in Washington State but, alas, both are annuals. Both do reseed, and the lack of return this year could be due to hungry birds getting to the seed before it could germinate, too much water, too little water, or a too-eager gardener pulling up in early Spring what was thought to be a weed.

We then went looking for a likely possibility in non-natives. Chrysanthemum maximum, commonly called the Shasta daisy, seems the best candidate. They are perennials and have widely naturalized in North America but are natives of Europe. Why did they disappear? Kind of a mystery, but again, it could have been water standing in the bed, which would have caused the roots to rot. Some perennials are referred to as short-lived perennials, which means they only survive a few years before they disappear, and since they were already there when you moved in, there is no way of knowing how long they had already lived. And can they be resurrected? Sorry, it would have prevented a lot of grief and mourning in our own gardens if such a thing were possible. If you decide to replant, the best time to plant as well as to divide depends on the climate in which you live. In Texas, we prefer to do both in the Fall, when the weather cools off (a little) and we can usually expect more rain. If you are in the more temperate climate of Washington, near the coast, you can probably do the same. However, if your average low temperature is 20 deg or below, you would probably be better off waiting for the soil and air to warm up in the Spring. Planting in the Fall means the roots can get established before the blazing heat of Summer. Planting in the Spring means the new plants don't have to withstand low temperatures before they get established.

Erigeron annuus

Layia glandulosa