Photos of our septic pad (from a variety of angles) are scattered through the rest of this (lengthy) blog post. (All photos are from August 19th of this year, by the way-- a few weeks before the last round of survey photos.) Here's one to get the ball rolling!
For those who don't know, when your home needs a septic system (usually because there's no city sewer system nearby to tie into), your soil has to pass a "perc test" (percolation test) before the septic system can be installed. Essentially, the test determines whether or not the soil drains quickly enough to make a septic system sanitary.
Our soil did not pass the perc test, so we had to have a septic pad constructed. This raises the grade of the land and improves the drainage. The downside of a septic pad is that it can sometimes be very obvious-- a large rectangular mound near the house. We're fortunate that you can't even see our septic pad from the front, because of the lay of the land and all the soil brought in before building our house. From the backyard, there is a decided slope on two sides of the pad, but I flatter (delude?) myself that it's not unattractive.
(We could eventually plant something other than grass on those slopes, but at this point, it's far down the list of priorities, since the grass is doing a decent job of controlling erosion. Gardening on the slopes would remove the necessity of mowing them, but they'd be quite a large addition to the area I'd have to maintain with weeding and mulching. I don't think I'm up for the challenge. Not unless Donald is bitten by the gardening bug and suddenly wants to spend hours every month weeding, too-- and that seems unlikely. (g) He has his own hobbies, and they don't include pulling weeds, strangely enough!)
But to get back to the point of this blog post... The top of our septic pad is very dry in the summer, and even after all these years (more than 15 years since the septic pad was first installed; over a decade since the house was built, which extended the raised area), the grass has failed to cover all of it, despite a feeble attempt or two at "sprigging" with grass from elsewhere in the lawn. Parts of it are reasonably well-covered with grass, but others are far more weeds (grassy and otherwise) than "good" grass-- then there's a less desirable grass that's slowly spreading across one section of it... (There's a fine example of the weed patch in the photo below.)
As a result, I've been toying with the possibility of creating a new flower bed on part of this trouble spot.
I've hesitated, since a new flower bed means more work, but if it's done properly, it can be a fairly low-maintenance flower bed. (As you'll read below, it really needs to be low-maintenance, according to the experts. If ever there's a place for an almost "self-tending" garden, this is it!)
Also, because it's right off the back of the house, overlooked by several windows, it's an area we see every day-- and therefore deserving of a little extra effort in the name of beautification.
I brainstormed a little, then did some searching and found, among other things, this useful page from Clemson. (The information is tailored for South Carolina, but much of it should hold true for the rest of the South.)
I was pleased to find that many of the plants I'd already jotted down are on Clemson's list of suggestions for planting over field lines. There is no shortage of options! Many of these are very hardy, prolific plants, so I can easily take divisions from the ones already in my garden.
First, it's very important to note that you should definitely not plant a tree-- even a small, ornamental tree-- or shrub over field lines. Those water-seeking roots can do extensive (and expensive) damage to the system, so save those plants for other places.
Next, it's recommended that you not dig or otherwise disturb the soil over the drain field any more than is absolutely necessary. Don't add additional soil, either, beyond what may required to repair erosion damage or slight unevenness in the grade. (So raised beds are out!)
The general rule of thumb in all matters is to leave the septic field as it is, as much as possible. For instance, avoid plants that need frequent division. Select tough plants that can survive with typical rainfall and naturally-present nutrients, reducing the need for frequent watering and fertilizing. It's even suggested that you keep the layer of mulch to a minimum-- something that surprised me. Apparently a thick layer of mulch can "restrict evaporation of soil moisture", which interferes with the function of the septic system. For the same reason, it's best to avoid groundcover plants that create too dense of a cover.
...To be completely honest, I think some of these guidelines may be taking things a little too far. Maybe there are situations where all this vigilance is truly necessary, but I suspect that our septic pad doesn't require this level of kid-glove treatment. But maybe I'm wrong. Maybe it really is that sensitive...
Two more suggestions:
--Try to limit foot traffic over the area-- and on a related note, choose low-maintenance plants that won't require frequent, hands-on attention (which of course increases foot traffic).
(Okay... But if you have lawn over the field, isn't the lawnmower going to be just as likely to compact the soil as the gardener walking here and there every so often? Also, our septic pad is part of our yard, not some sacred nesting-ground of a nearly-extinct species. It is meant to be used, so we'll use it. If the "traffic" of us and our dogs walking and-- dare I say it?-- running over the septic pad eventually does lead to it needing attention, I guess that will just be part of the expense of living and being a homeowner!)
--"Always wear gloves when working with the soil in the drain field area to minimize your exposure to the soil and any harmful organisms in it. This applies to many gardening activities such as digging, planting and weeding."
(I have no plans to plant fruits or vegetables on or near the field lines, and I'll almost certainly be wearing gloves when I do the initial digging of the proposed "pad bed", but I really do think that there's an over-abundance of caution on display, here. So I can't even pull weeds on the pad bare-handed without risking some sort of... contamination? It's a wonder I haven't contracted septic-system-itis by now! I've definitely pulled weeds, dug, and planted in soil along the edges of, if not directly in the center of the septic pad-- and I'm sure I wasn't always wearing my handy-dandy hazmat suit-- or even gloves. It never occurred to me to worry, and so far, it seems there was no serious need for concern. ...But thanks for giving me something else to worry about!)
...I think that covers all the (many, many) rules about what you can't or shouldn't do. Now let's get to the fun part-- the options for planting!
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I'm focusing on my own personalized, semi-narrowed-down list of possibilities, but the link further up the page includes quite a few more.
So, based only on what I already have in the garden, ready for division/propagation/transplanting (or have already ordered to arrive this fall, in the case of some of the bulbs), here are my ideas for plants in full sun and dry soil:
--purple coneflower (Echinacea purpurea)
--blanket flower (gaillardia-- may function more as an annual)
--yarrow (drought-tolerant, but can be invasive, depending on species/variety)
--Mexican petunia (Ruellia brittoniana 'Purple Showers'-- in a sunken pot to restrict its spread?)
--bat-face cuphea (not sure yet if a true perennial here, but very good summer grower)
--purple heart (Tradescantia pallida or Setcreasea pallida)
--orange daylily (either plain single or 'Kwanso')
--black-eyed Susan (Rudbeckia fulgida var. sullivantii 'Goldsturm')
--swamp sunflower (Helianthus angustifolius, not sure about dry conditions...)
--succulents (sun-loving succulents in a pot)
--bog sage (Salvia uliginosa, despite the name, reputed to adapt to dry soil, too. This one is not on Clemson's list, by the way.)
--muhly grass (Muhlenbergia capillaris)
--river oats (Chasmanthium latifolium, can be aggressive spreader if seeds not removed)
--montbretia / crocosmia (in a sunken pot to keep somewhat contained?)
--Spanish bluebell (Endymion hispanica)
--star flower (Ipheion uniflorum)
Clemson's list of recommended plants doesn't include specific annuals-- perhaps because they can require more foot traffic and disturbing the soil to replant every year-- but they do say that annuals can be used.
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Next, there's the option of garden ornaments.
--We have a small sundial that could look nice on the edge of the proposed bed.
--An obelisk (with or without a vine, because an obelisk can also provide support to nearby non-vining plants) could also add another element of all-season interest.
--A tall and/or largish container (planted with succulents, possibly, or a grass or drought-tolerant perennial or annual) could provide a focal point-- but I imagine the experts would say that it's best not to have something solid covering much of the field lines area, as it could impede evaporation. One or two pots shouldn't be a problem, though.
--We have a small bird-feeding station we're working on, out in the garage. (It's on pause until cooler weather.) We'll have to be careful, when we dig the hole to put up the post, to be sure we don't dig into a pipe or something... It would also be possible to just place a simple shepherd's hook from which to hang a small (lightweight) bird-feeder. The feeder itself is something to look at, and if you succeed in attracting birds, they fill the garden the movement and interest. (A birdhouse-- decorative, functional, or both-- is another option.)
--I can imagine a small section of picket fence (or an old bedstead) looking charming in a wildflower / meadow-style / naturalistic planting that would be well suited to the parameters of field line landscaping.
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Now that I've more or less decided that I will make a flower bed on the septic pad, I have to start thinking more specifically about where exactly I will position it and how big it will be. Originally, I was planning to fit an oval into the curve of the existing border, but now I'm not so sure. I might nudge it down a bit further.
This is the view from the back patio (and there's a very similar view from the house).
Would it be nice to look out over a grassy path (wide enough for the mower) and see a casual flower bed there? What shape would it be? A fat oval or more elongated? (It must be easy to mow around, and I prefer curves to straight lines.)
Or would it make more sense to scooch it off to the right, leaving the area directly in front of the patio as open lawn? My current inclination is to site the new bed in front of the patio, even if it's not centered there.
If/when there's a new flower bed here, the views from the gravel path will change significantly between this summer and next. I think it will be an improvement.
If this summer ever actually goes away, this new proposed flower bed will be one of the main undertakings for the cool season. Even if I don't do the planting before spring, I will have plenty to do just settling on its location, handling the grass/weeds already in place, putting down mulch, and deciding on a layout for plants and small ornaments.
At this point, the possibilities seem endless!