Walt’s Notes for March/April

Can’t stop it – the advent of spring! Even with our cool to cold weather and quite a bit of rain to further keep temperatures down, buds are emerging, flowers appearing – it’s a busy time for the senses. One of my favorite harbingers of spring is the Oso berry, formerly known as Indian Plum, Oemleria cerasiformis. There’s some in the lower meadow and along the south path. You won’t get any odor from the white flowers but sniff a leaf and most people will smell cucumber. It’s an easy way to identify it in the summer when there are no blossoms. On the female plants (this is a dioecious plant, meaning with separate sexes on plants), bluish ‘plums’ will appear in the summer. It’s a thin coating that has to be quite ripe to get much flavor from the fruit. You might notice awkward little March flies and maybe some bumblebees performing pollination services right now.

Lots of the forest floor plants are taking advantage of the extra sunlight right now under deciduous trees that will leaf out later. Quite noticeable right now are a myriad of bulbous plants. Yellows with King Alfred daffodils and primroses, pinks with cyclamen, white with Liverleaf/Hepatica nobilis, blues, and purples with Muscari/Grape Hyacinth, pinks with Corydalissolida and some Hellebores. In dappled light, they last longer and still put on a good show. I like the slow carpeting of Cardamine quinquefolia; both the divided leaflets and taller purplish blossoms are elegant. If the genus name Cardamine rings a bell, it is indeed the same genus that holds the bane of some gardeners, the shot weed.

Trilliums are starting to shoot upward; this one, Giant Wakerobin/Trillium chloropetalum is always an early one. Dark colors or just mottled foliage helps absorb some solar heat. You’ll see it on the Coast Fawn Lily/Erythronium revolutum leaves too.

Hard to believe but Cornus mas is indeed a dogwood. It just doesn’t have the ‘petals’ (which are actually modified leaf-like structures called bracts) that we associate with the regular flowering dogwoods. Its common name further adds to the confusion – Cornelian Cherry! It does get a very red fruit with a pit in late summer that is edible although rather sour in most cases. With the masses of tiny flowers, it really shines if placed against a dark background like an evergreen hedge. Slow growing, it gets to 15’ in our gardens. (Bracts are the red, pink, or white ‘petals’ of Poinsettias too!)

Another yellow early woody plant is Corylopsis glabresens, one of the wintersweets. Spicy fragrance on these wide-spreading forest edge shrubs (this one can get to 8’ and more but easily kept in check). If they get enough sun, expect a gorgeous display of yellow foliage in the fall. They’re good plants to garden under with early flowering bulbs such as those mentioned already.

P.S. Check out my article on Indian Plum in the UW Arboretum Bulletin Spring 2006 issue; it’s online.

Walt Bubelis
Professor Emeritus, Horticulture Edmonds College

Hepatica nobilis

Corydalis solida

Cardemine quinquefolia

Erythronium revolutum

Cornus mas

Corylopsis glabrescens