The Elk Grove Rain Garden Plaza Continued
Thank You Very Mulch
Exploring the Rain Garden and What You Will See
Salvia spathacea, aka Hummingbird Sage and loads of mulch
Let us be clear about a few things. First, when you go to the new Rain Garden Plaza in Elk Grove www.elkgrovecity.org you will see lots and lots of mulch. And if you try to take a photo of the lovely plants in the mulch as I did, you’ll get a detailed image of, well, some really nice fresh, uh mulch. It’s not really a mulch garden but that’s what a proper new landscape looks like at first. Landscapers like to use mulch to protect the soil from erosion, hold in precious moisture, protect plant roots from heat and cold and eventually provide nourishment for the soil as the mulch breaks down. So be patient, come back often to visit. And witness the great mulch disappearing act as the plants spread and cover the soil.
Is it a Rain Garden or a Xeriscape?
water lovers below deck, dry lovers on the slope above
Confusing isn’t it? The Plaza is billed as a rain garden. It does deliver a delightful year round rain garden chock full of colorful and interesting plants that thrive through both wet winters and hot dry conditions the rest of the year. The rain garden proper is the sunken area along the boardwalk where water will collect before sinking into the soil. Watch the Blue Thumb Blog later this summer for a list of these specialized type of plants that tolerate wet feet in local rain gardens. The entire one acre of the plaza drains into this basin and is designed to hold all the water that falls on the park except in flood conditions. But the rain garden plantings are actually a small percentage of the total mass planting in the plaza.
sedges in the dry garden
What else is happening there? Well the rest of the park is a drought tolerant garden. That’s right, a big xeriscape draining into a specialized pit of rocks. And it’s gorgeous! What you are seeing is a collection of plants which are specially suited to handle our famous Mediterranean climate and our long rainless months of desert conditions. Many lovely California natives also make an appearance here. Xeros is Greek for dry, so a xeriscape is a dry landscape. A xeric plant is one that loves dry conditions. No such thing as a ‘zeroscape’, as some folks believe.
IMPORTANT: Notice that I have described two distinctly different plant types you will see in the Elk Grove Rain Garden Plaza:
- water loving plants
- dry loving or xeric plants
These two groups of plants have very different watering needs. You would not have much success if you tried to plant the water lovers in the dry mounded planting beds. And the low water plants would quickly drown and rot in the rain garden basin. But notice that these plants are grouped in the beds according to their water needs. This is a basic rule of landscape design for all thriving gardens: Group plants together with similar water requirements so that each one gets neither too much nor too little water. This little trick is called hydrozoning, and you can use it successfully in your projects too.
You Should Know: Knowledgeable landscape professionals use a guide for hydrozoning called WUCOLS, or Water Use Classification of Landscape Species. You can find this technical document online, or make some more general guesses by using a Sunset Western Guide.
Try This: My favorite way to find plants and hydrozone them for homeowners is to use the UC Davis Arboretum All Stars plant list. Here are 100 plants tried and tested especially for Sacramento Valley conditions. http://arboretum.ucdavis.edu/arboretum_all_stars.aspx
Got questions or need some help? Call a Green Gardener:
http://www.bewatersmart.info/water-smart-gardening/green-gardener/
Tour more of the Elk Grove Rain Garden Plaza with me in my next blog…
Arbutus unedo aka Strawberry Tree is a UCD All Star. We also note that this newly planted young tree is properly staked.
