Yesterday, I added another section to the border along the dry creek bed, at the wettest end. Because of the way the stream is sloped, this strip isn't flooded even during a major downpour, but it is quite wet and stays somewhat moist even in summer. In winter, it receives some morning light, and in summer it experiences full sun, with some light afternoon shade. I moved the variegated Japanese iris from the back patio and the Daboecia cantabrica (Irish heath) from Stump St. Helens to this new border in hopes that the more stable moisture and a bit of afternoon shade in summer would improve their performance and appearance. Lack of sufficient water off the back patio resulted in pleated leaves on the iris that bleached in the strong sunlight, nullifying the variegation and burning leaf tips. Similarly, the Irish heath suffered from summer drought. Though it is remarkably drought-tolerant in acid soils, this plant which should bloom all summer only managed a few spring and fall blooms when natural rainfall moistened the ground. The drought stress also resulted in many dead branches.
Accompanying plants include Carex comans and Juncus effusus. I'm already happy with the simple green and silver of the sedge, rush, and Irish heath, the latter of which also has white leaf undersides. I need to add more of the same to the bed on the opposite side of the creek bed, in the photo above, to tie them together.
I also added a few clumps of Mimulus cardinalis and divisions of a blue Siberian iris. The Siberian and Japanese iris will provide bursts of spring color, while the Irish heath and monkey flower will bloom virtually all summer. Next summer, I'll have to judge whether the orange monkey flowers and white and pinkish-purple Irish heath clash or not. I am adding the monkey flower to my list of plants that I enjoy even in their dead, winter appearance. The texture works well with the sedges, rush, and heath foliage. It's also a bit of an experiment to see if the foliage of the irises will cause problems, such as shading out portions of the Irish heath.
Twenty or 30 feet remains between the new section at the wet end, and the first section put in a few weeks ago at the corner of the dry creek bed, pictured below on a frosty morning. This corner is the highest point of the creekbed, and also the sunniest. It's been planted with Molinia caerulea 'Variegata', Rudbeckia fulgida 'Goldsturm', and Calluna vulgaris, which may not appreciate the dense foliage of the Molinia flopping onto it all summer. That may require some adjustment. The two sections have drastically different plants and appearances, and I'm currently thinking of what to plant in the middle section to make a smooth transition. Right now, I'm thinking more rushes and sedges planted along the entire border to draw everything together. I have some Phygelius I can plant in the middle section, and can divide my kniphofias to intersperse along that section as well. I think I may divide the Molinia and plant it further along the border, too.
I also planted two Cotoneaster microphyllus var. thymifolius on either side of the dry creek bed near the weeping blue Atlas cedar and the back patio bed. I noticed that the tiny hairs on the cotoneaster leaves catch the early morning sunlight, glowing and highlighting the herringbone pattern of the dark stems. I want to get a couple more to plant on the other side of the cedar to prolong the morning show.
I'm hoping the pair will help tie the areas together across the creek bed. I also like how the unusual shapes echo slightly the growth habit of the cedar, and even the Poncirus trifoliata 'Monstrosa', and contrast with the neat, tidy globes of the Abies balsamea 'Nana'.
That was yesterday. Today is a typical, dark, wet December day in the PNW. The heavy rain highlights drainage issues, like the one shown below. The dry creek bed directs water away from the house, but has nowhere to go at the end. This area always had some standing water during heavy rain, but has even more since the creek bed went in.
It sheets across this section of the driveway. I'd like to create a sunken garden by digging out the area right at the end of the dry creek bed in the photo above, filling it with plants that tolerate seasonal flooding. It couldn't be too deep, because there's a water line running through that area. I'd also have to figure out a path around it or a bridge over it. Another small sunken area could be created where the water is pooling in the photo below. Dig it out a bit to catch more water before it floods the driveway.
This new bed connects another Magnolia 'Silk Road' x insignis with an Embothrium coccineum. Before, the water probably flowed between them. Now it's blocked by the slightly raised level of the bed.
I don't really feel that the last two puddles are real problems. The puddles disappear soon enough after the rain stops, and the plants aren't particularly sensitive to poor drainage. The small puddle below, off the south end of the house, is actually more concerning. This bed is a summer-dry bed, with many plants that require good drainage. Unfortunately, the soil is terrible, compacted clay. I've had a surprising amount of success with only minimal amending of soil. This end, however, gets more water in winter and is proving to be the most troublesome.
I'm positive that the main problem is this area around the corner (which I lazily photographed through the screen, sorry). The contractors put plastic and a dense weed barrier under the mulch, which has washed away in areas, exposing the weed barrier. The soil underneath is more compacted clay. I don't think they realized when they did this that so much water would collect here. Much of it comes, I think, from the concrete patio. The already-fine mulch they used has broken down to the point where it supports numerous weeds, making the weed barrier useless on top of being ugly and worsening the drainage issue. I'm definitely tearing it out. But what to do about this area? It would be nice to actually connect these steps to the path. Personally, I think it's bizarre that this wasn't done in the first place. I'm considering pavers to form a small patio off the steps, with crushed rock between them, and groundcovers on either side, creeping into the gravel at the edges. The patch of Satureja douglasii is just outside of this shot to the left, and it would be easy enough to move pieces of it to fill in around the pavers. A few sparse plants poking through the gravel between the pavers would finish it off. It would look so much better (and be easier to walk across) than this typical PNW-style mulch and scattered rocks.
I don't think that would entirely solve the drainage issue into the bed around the corner, though. Perhaps a channel at edge of that bed? Or adding some perforations to the drainage pipe that runs water from the downspout, under the bed and pathway, and into the dry creek bed.