Raingardening Lessons

If you Google rain gardens, you will be informed that there are 122,000 entries on this subject. Just out of curiosity, I went to a number of the sites listed to see what kind of information was available. I am happy to say that if you are an experienced gardener with vast knowledge of gardening techniques and field experience with hundreds of plants, you can probably find the information you need to create your rain garden. If you're not, you'll find just enough information to whet your appetite but no where near enough to actually design and install your garden.


And what if you're new to gardening? What if you don't know how to choose the best tools, know nothing about creating any type of garden and even less about what is required to take it from an idea to an in-the-ground landscape feature.

Yes, I'm going to plug my Rain Garden Handbook now.

Over the many years that I've worked with clients, I've found the biggest impediment to their gardening success was lack of understanding of the basic principles of gardening, those being how to select your garden site, understand the cultural requirements of the plants you specify for your garden, purchase healthy plants and plant them properly and then know how to provide the needed support until they become established. Oh, and what do you do to maintain your garden, what is required season by season.

So my book, The Rain Garden Handbook will help you learn everything you need to know to become a first class gardener. It contains detailed information for a very good reason. No matter whether you live in Michigan, Montana, or North Carolina, there are plenty of good plant materials and soil amendments available so that you can create the best rain garden possible for your agricultural zone.

Gardens should thrive, not just survive. Let's make a rain garden together!

This picture of Hibiscus cocineus blossoms was taken after three weeks of temperatures in the 90's with breezy conditions. The rain garden plants were looking a little 'fainty'. On Monday of this week, with heavy clouds seeming to almost touch the earth, we received 3/4" of rain. The next morning I was able to snap this shot. The rain garden plants miraculously perked up and remain that way on Friday morning. Careful selection of your plant materials should produce a garden that looks good spring, summer, fall and winter.

Freedom from 'rattiness'

Happy 4th of July!

This morning I headed toward the rain garden with scissors in hand. I had two items on my lengthy To-Do List that I planned on knocking off. First to the Acquilegia canadensis (wild columbine) to trim the browning seed stalks, all that's left from this springs beautiful blooms. After cutting, I tucked them into a plastic grocery bag to take with me to The King's Daughters Inn so that I can sprinkle little brown seeds throughout their rain garden. The wild columbine is somewhat difficult to find but is well worth the search as it is a lovely plant, grows easily and puts up with very dry conditions.

My second chore was to 'liberate' the Tradescantia virginiana (spiderwort) from its ratty look. I'm being kind when I say it looked ratty. Don't get me wrong, I really enjoyed it during its glory days in April when it produced hundreds of royal purple blossoms that looked absolutely great beside the red of the wild columbine. Now, the first of July, it has declined in appearance to a point that makes me winch when I walk past the rain garden. I moved it last fall to a position farther back in the garden, anticipating this transition to the forlorn. I had intended to let it go until all the shoots had yellowed completely before cutting it back. There was still some green in the stems but I couldn't take it anymore. So the compost heap received an 'offering' today. The ratty spiderwort is adding greens to the pile. I'll dump the sweet corn husks on top of it later today when I start our 4th backyard cookout and then it will be forgotten until next spring when it again takes its place as the prettiest April flower in the rain garden.

The Ellerbe Creek Restoration

This is the section of Ellerbe Creek that I see from my porch. It sits directly across the street on the edge of Northgate Park. In this picture you're looking at a section of the creek that was restored during the winter of 2008/2009. Those gently sloping banks are part of the restoration. This section of the creek used to look like a deep V cut into the ground with the creek running some 14 feet down its steep banks. It got that way over the years because large volumes of fast moving stormwater collasped sections of the upper banks creating the V shape. That soil washed down the creek and some of it ended up in Falls Lake, a source of drinking water for the city of Raleigh.

During a heavy storm event of some duration, the creek would become a river and then slowly flood out to cover the entire park before it crept across the road and into our yards. We lost a good family down the street when they sold their house after the basement had been flooded twice in one summer. The FEMA flood map has been revised to expand the size of the flood zone in this area.

It didn't used to flood that badly but when a lot of development was done upstream with large expanses of parking lot, the volume of water increased. Whole forested areas became shopping centers. Housing developments also added to the impervious surfaces with roads, sidewalks and rooftops. We could have mitigated more than half that volume of water if those houses had added raingardens to their yards........And that is why I have a rain garden blog, to help others see what we each can do to help solve the problem.

Fixing "Impaired" water sources

From The News & Observer's June 25, 2009 Editorial section: Title - A cleaner Falls, faster. Falls Lake is the drinking water resource for 435,000 in Wake County, North Carolina. Unfortunately, under federal clean water standards, the lake is impaired. The editorial goes on to state that high levels of both nitrogen and phosphorus are causing increases in algae in the lake. You know what algae looks like, that sickly green stuff that clouds the water or if enough exists, floats like large clouds on the surface. This makes the water harder to clean for drinking purposes.

And of course, the source of this problem originates upstream, in this case, Durham County whose rivers and streams feed both Falls and Jordan lakes.

The editorial acknowledges the difficulty of the work necessary to reduce these levels, especially with a state budget crisis.

So are our lush green lawns causing problems? Well, in a word yes.

The importance of rain gardens becomes clearer now. We don't have to wait for our officials to take action, because we can start solving the problem right now by installing a rain garden in our yard. No, it won't be a total solution. Businesses large and small will also need to create mechanisms to catch their rain water and prevent it from entering our waterways.

But we can start. Think about it.

Visualize the volume

It's pretty hard to visualize how much space 6500 gallons of water would fill for the rain water we have diverted from the storm water system so far this year.

Out of curiosity, I checked out how many gallons of water it takes to fill a small swimming pool that is 12 X 24 with an average depth of 5.5 feet. Water capacity for that size pool is 12,420 gallons. So far this year, we could have filled half a swimming pool with the water that didn't go into the storm water system.

If you've ever watched America's Funniest Home Videos, you have seen what happens when the walls of an above ground pool collapse. Everything including people get swept away with the surge. Multiply that by 10 for impact. This gives you some idea of the benefits a rain garden provides for local streams that aren't being impacted by our run-off. Again, if 10 houses in our neighborhood did this, we would have prevented 4 or5 swimming pools worth of water from hitting the storm water system and the creek across the street. We would also have stopped the chemicals those waters contained from landing in our water sources.

Think about it.

seedling or weedling

In the Ongoing Care section of my book, I talk about differentiating tiny seedlings of the plants you want from the unwanted plants that sprout in your rain garden soil mix. Here is a tiny Baptisia australis (Blue Wild Indigo) growing among Sedums and Houttuynia. Although tiny, the leaves match exactly that of the parent plant. When in doubt, let it grow a season and then check it against the parent plant again. Baptisia australis will grow well in regular garden soil as well as your rain garden soil mix and this little one could be transplanted to another area of the yard in fall.