Keeping trellises from becoming monsters

By Stephen Lamphear

September is Northwest Natural Yard Days at many local retailers, helping residents practice environmentally friendly yard care. Promotional prices are offered on environmentally friendly garden products at lawn and garden centers, home improvement centers and various nurseries throughout King County.

Northwest Natural Yard Days is sponsored by the partnership of King County Solid Waste Division, the city of Seattle, and Water Districts No. 20 and 45 to encourage residents to practice environmentally conscious gardening without breaking the bank. Discounts up to 20 percent are offered just in time for fall yard care projects.

Q: I'd like to put a couple vines on a trellis. It's not a particularly stout trellis so I'd appreciate some suggestions that won't turn into monsters.

A: It's wise to think about the strength of the trellis before selecting your vines. Some vines, like wisteria, evergreen clematis, akebia, kiwi and trumpet vine become substantial and can crush or collapse any but the sturdiest structures. I've seen them consume a house! Fortunately, there are many better behaved critters.

In a sunny location, selections include passion vine (Passiflora 'Constance Elliot', P. caerulea, P. incarnata, and P. 'Incense'), Chilean jasmine (Mandevilla laxa), Banks rose (Rosa banksiae), honeysuckle, hardy jasmine (Jasminum x Stephanense), most clematis including evergreen Clematis x cartmanii 'Early Sensation' aka 'Avalanche' with its highly dissected leaves, and C. fasciculiflora with striking evergreen silver-veined leaves.

For a partially sunny location, choose variegated porcelain vine (Ampelopsis brevipedunculata 'Elegans'), Star Jasmine (Trachelospermum jasminoides), Carolina jessamine (Gelsemium sempervirens).

As you can see, available selections decrease as shade increases. Not surprising since the whole purpose of being a vine is to reach for the sunlight.

Q: I've been noticing Australian cabbage palms seem to be hardy in the Puget Sound basin, but they're usually sold as filler for summer container gardens. What's the scoop?

A: The cabbage tree or palm (Cordyline australis) is native to New Zealand and indeed both are hardy locally and sold as little more than container filler. While the green version of cabbage palm has proven it can cope with our winter, the burgundy version may not be as hardy. Give these interesting trees a chance to be all they can be.

A fast grower, this member of the lily family can become a significant small stout tree or shrub up to 20 feet tall and considerably wider. With age, larger plants offer fragrant creamy white blooms in early summer after which the trunk may divide as the plant develops its tree form. Happiest in fertile soil, Cordyline is a good choice for poor, rocky locations.

Late summer and fall is the time for sowing seeds of biennials, plants that take two years to grow and bloom. Popular biennials are foxglove and sweet William. Sow seeds in a quality propagating mix in leftover pony pack pots and keep well watered until rains are dependable. Next spring, transplant out to where they are to bloom.

Stephen Lamphear can be contacted at lazy.gardener@comcast.net