Blooming forsythia tell you to trim roses

E-mail this article Print this article Other links

Q: When should I prune roses? Mine are beginning to put on leaves.

A: A great tip I recently read says "prune your roses when the forsythia bloom." Even if your garden holds no forsythia, the bright yellow of this early shrub shines all over the Northwest, so they're easy to see in parks and landscapes. The opening of the forsythia flowers signals warmer, settled spring weather. Just now forsythia in my garden continues to respond to freezing nights by staying firmly folded inside its protective buds.

Gardeners in the past relied on observation to choose when to act. This observational skill is called "phenology," an odd word that sounds a bit like weird, 19th-century psychology. It means looking at the unfolding of the seasons through the appearance and behavior of plants and insects as they respond to the weather.

Roses pruned too early risk having their expanding new growth harmed by freezes, which would set the plants back in their summer development. Before pruning, check a good garden resource on how to prune. In particular, if you have climbing roses, be careful to allow the long lengths of canes to remain. (Sometimes gardeners cut their climbing roses down to the ground, which costs them a season's bloom.)

One good pruning book is: "Roses: How to Select, Grow, and Enjoy" (Ray and MacCaskey, HP Books, 1985). A general look at roses here in the Northwest is Rhonda Hart's book "Northcoast Roses" (Sasquatch Press, 1994). Another excellent source of information is the annual rose-pruning demonstration at the Woodland Park Rose Garden at the Woodland Park Zoo in Seattle. Watch the newspaper for the date of the pruning.

Q: Can you tell me about some fragrant early spring shrubs?

A: I'm listing below spring shrubs that also are tolerant of dry summers, because one of the responsibilities of Northwest gardeners in the coming years will be conserving water. When planting these, plan for their water needs during the first season, with soaker hoses to water them through their first summer. After that, they can manage on the small amounts of rain naturally present in maritime Northwest summers.

• The shrubby daphne (Daphne odora `Variegata') looks handsome all year round, and has grown slowly to a shrub about 3 feet by 3 feet (in eight years). The evergreen leaves are a medium green with a distinct white border. What send gardeners into rapture about this plant are the flower and scent. Buds, now fully formed, will open within three weeks into pale cream and pink flowers with a fragrance combining citrus and jasmine, deeper than orange-blossom fragrance, but also quite fresh. It blooms in February and into March, and spends the rest of the year in quiet, green retirement. Plant it in semi-shade and allow it to experience dry summers. It blooms better when not watered in summer. (Just keep it watered through the first year to get roots established.)

• Viburnums, a big tribe containing lots of garden shrubs, have several early-blooming types. In flower now is Viburnum bodnantense `Dawn,' which carries clusters of pink flowers that bloom off and on from December through March. The fragrance is as sweet as the color, a soft scent a bit like old-fashioned baby powder. This shrub loses leaves in winter and can get to about 10 feet tall, with a gawky form. It's completely hardy to summer drought once established.

Other early blooming viburnums include the Korean spice viburnum, Viburnum carlesii. It's generally evergreen, with pink buds opening to white, and excellent fragrance in March when the flowers open. Viburnum Tinus, a tall evergreen shrub, blooms from November through March with large clusters of white flowers. Its common name is Lauristinus, and the flower fragrance depends on the nose of the observer: it's been described as both "pleasant" and "essence of wet dog." This one is good for hedging and screens, and grows as high as 12 feet.

All these shrubs can shelter early-blooming snowdrops (Galanthus nivalis) and small daffodils such as Tete a Tete. Those bulbs don't require summer water during their dormant period from May through September - so they make great companions for these attractive and waterwise shrubs.

Mary Robson is the area hortriculture agent for Washington State University/King County Cooperative Extension.