Culvert planters, Part 2

If you check out a certain League City grocery store right about now, you might see some of these for sale, unless they've already been snapped up by eager local consumers.

So for eighty-five bucks plus tax, you too could have a planter that looks quite a bit like a piece of highway culvert.  Or, you could simply use a piece of highway culvert, maybe even for free if you can manage to upcycle discarded scraps, as I did. 

From my post of a month ago titled
"Culvert planters, Part 1". 

Part 1 presented a build sequence for the singleton pictured above.  Here's another installation I did using a group of three segments (the basic building steps are the same as in Part 1, so I will not repeat them here):

This pic was taken last year while I was growing basil, cantaloupe, and onions in these.  This was also before I had trimmed out that bull rock surround with landscape edging. 

By the way, Wayne's Landscaping on Dixie Farm Road has the best price on bull rock that I've found on the south side of greater Houston.  Many places, such as Living Earth, do not sell it by the pound - you have to buy a cubic yard or more.  As of April 2013, Wayne's was selling it for $0.06 per pound (bring your own containers or heavy canvas bags if you just need to buy a few hundred pounds such as what's pictured here). 

Here's what to keep in mind if you're going to do a culvert planter grouping as opposed to a singleton:

1. Use the "Rule of Odds" to maximize artistic impact.  It's no accident there are three culverts here, instead of two or four.  I have talked about the rules of thirds and diagonals (e.g., in this post on landscaping lay-outs), but I don't think I mentioned using odd numbers previously. 
2. Make the culvert pieces interrelate, such as by using smoothly staggered heights (it's difficult to tell from this photo angle, but each successive culvert is about one foot taller than the one before it).
3. Relate the grouping to the area in which they are placed.  Notice how the two sides of this concrete patio skirt converge right where these culverts are now placed.  In simpler words, I put them right at the corner of the patio.  This placement emphasizes their grouping as a focal point.  It also softens the harsh pointed corner of concrete. 
4. Depending on your application and style, it can also be helpful to make the culvert pieces pay visual homage to their source.  Real installations of highway culvert are often surrounded by bull rock or an equivalent coarse aggregate.  To echo that in a residentially-acceptable way imparts an extra element of artistic design innovation. 

I tend to describe our design style as "organic industrial", so it makes sense for me to cross-reference culverts poking out of coarse rock, analogous to what is actually seen along streets and highways. 
Screengrabbed from this site. 

Even if you don't use rock, you'll want to surround your culverts with something other than lawn, or else the bottoms of them will get torn up by string trimmers ("edgers").  Maybe set them in a mulched bed or xeriscaped area, if you don't like idea of surrounding them with rock. 

These culvert triplets are a larger diameter (24") than the singleton I described in Part 1 (18").  That has given me a bit of extra latitude in what I can plant in them.  It also has allowed for the use of specialized soils.

Here's what they looked like after the past two days of torrential rains.  You'll notice the black polyethylene lawn edging is now in place around the bull rock to give it a neater, more finished appearance.  Please ignore that skanky Swiss chard in the central tall culvert - I plan to get rid of that.  What I'd really like you to notice is the plant in the far left culvert.  Here's a close-up...

Artistically AND functionally, this rates a 'wow'!!!  BLUEBERRIES, one of the most remarkable superfoods on the planet (heart health potential here, anti-cancer properties here). 

Growing blueberries in greater Houston is not an automatic process.  Blueberries require soils that are significantly more acidic than most native soils - generally they require a pH between 4 and 5.  I haven't tested my soils, but Houston soils can easily have a pH as high as 8.0.  If you know anything about the pH scale, you'll know that it's logarithmic, so we're talking about a vast gulf between our natural conditions and soils that will support blueberry growth. 

This is a close-up of the blueberry bush in the shortest culvert.  The poor leaf coloration tells me that I'm still struggling to attain supportable soil conditions in this one.  Nevertheless, this small discolored bush did produce berries this spring, as you can see.  More importantly, it successfully cross-pollinated the healthier bush in the taller culvert.  You can't just have one blueberry bush because they need to talk to each other genetically in order to bear fruit.  Blueberry growing is rare in greater Houston, so it's not like your neighbor's bush is going to get the pollination job done for you (because your neighbor doesn't have a bush). 

To date, I've achieved most of my pH-lowering by daily feeding of these bushes with my spent tea leaves, although recently I've begun to augment that with peat moss and a bit of sulfur because tea hasn't proven to be sufficient by itself.  I drink a few liters of tea per day, so I generate a lot of used tea leaves.  Spent tea and also coffee grounds do help to reduce the pH without shocking the plants like sulfur can.  I grab recycled coffee grounds from Starbucks whenever I come across them - they're a particularly valuable soil amendment here in Houston where alkaline soils can kill many desirable species.  I kept an in-ground gardenia alive for many years at one of my former houses by religiously feeding it Starbucks coffee grounds. 

My husband had a very good point about my choice of polyethylene culverts for blueberry plants: our metal stock tank gardens would not be expected to stand up long term in pH conditions as low as 4.0.  They would probably rot out (corrode).  Therefore, acid-loving plants such as blueberries are better grown in some kind of non-metallic enclosure. 

There isn't a single other gardening success that has been as rewarding for me as growing that first small crop of blueberries pictured above.  Nothing improves my mood like wandering into my back yard and seeing a new handful of ripe berries waiting to be eaten.  They don't taste like a typical mass-produced agricultural product - they taste like natural wild fruit.  I have every intention of expanding this growing effort in the future, using more culvert pieces or some other new as-yet-to-be discovered microscopic back-yard gardening strategy (this Aggie site suggests whiskey barrels, but I don't think they'd coordinate very well with highway culvert!). 

I guess I got really lucky this spring because of our record-setting cold temperatures.  Anyway, here's a picture of another blueberry growing idea, much simpler than using highway culverts.  However, if you use smaller containers such as these in greater Houston, you'd have to be extremely careful not to let them dry out during our hot season.  They would need to be watered daily, or maybe even multiple times per day, in order to keep the plants alive. 
Screengrabbed from this Aggie site.