Urban Landscape, Native Landscape: July 2008

Perennial Garden

12 Important Pieces of Advice:

1 A small space is best for a perennial garden. Larger spaces need shrubs.

2 Perennials should vary in form & texture. There are many strap-leaved perennials & grasses. Too many together is boring. Put rounded leaves next to spiky ones.

3 Alternate plants of different heights, but not rigidly.

4 Limit colors to avoid chaos. Blend more than contrast. Use blue with purple, yellow with orange, pink with orange & purple, red with purple & blue.

5 Use perennials that bloom in every season. Visit nurseries often to see what is blooming. Read Bloom Times.

6 Buy 2 or more perennials in interesting color combinations when shopping. If you like something, buy more later.

7 Remember that bulbs & grasses are perennials.

8 Use trailers & groundcovers.

9 Consider native perennials, especially in shade.

10 Do not become fixated on the number 3. Everything in triplicate looks highly contrived. Use the numbers 2, 3, 4 & 5 equally. Use 1 sparingly.

11 Understand that good design evolves over many years.

12 Visit open gardens with the Northwest Perennial Alliance, the NPA.

Read How to Make a Garden.

Echinocereus reichenbachii albispinus May 2009

Agave palmeri May 2009

Anthemis biebersteiniana & Campanula carpatica May 2009

Yucca harrimaniae August 2008

Penstemon x mexicali ‘Red Rocks’ June 2009

Sedum dasyphyllum June 2009

The stony slope was made on dry southeast-sloping ground near the southeast edge of the Cascadia Garden. Sandy native soil was retained with low stone walls. Hundreds of stones, mostly small stones found on site over 40 years, nearly covered the soil. Larger stones were purchased & put in place. An inch of gravel was spread over the planting beds & the path between. The 1st planting was begun in late spring of 2004. Because these were arid plants, the planting was done near the end of the rainy season. Bulbs from western & central Asia were planted in October. The garden was explanded by 6 feet in 2006. Arctostaphylos columbiana was planted at the northern end. Spreading Epilobium & Veronica pectinata took up most of that space. Echinocereus showed spectacular pink flowers starting in 2007. Yucca whipplei doubled in size each year until it shot up a stalk 8 feet tall with 100s of flowers in 2007, then died. It was followed by Agave palmeri which produced a flower stalk 15 feet tall in 2009, then died. Although I knew this was their lifestyle, the large holes they left behind were discouraging. I replaced the Yucca with a small Arctostaphylos ‘White Lanterns.’ I replaced the Agave with Yucca schottii which lives to flower yearly.

Stony Slope Plant List

Shrubs

Arctostaphylos columbiana (Hairy Manzanita)

Arctostaphylos 'White Lanterns'

Helleborus argutifolius (Corsican Hellebore)

Mahonia pinnata ‘Ken Hartman’

Penstemon pinifolius

Woody Lilies

Agave palmeri

Agave parryi huachucensis

Agave toumeyana bella

Nolina parryi