Sump liners = mini-bogs + potato-tubes

This is a sump liner, also called a sump basin.  It is the solid kind, not the perforated kind.  It is used as part of a basement sump-pump system to (you guessed it) line the sump pit you might find in a corner of your basement.  They cost about $30.00 here in Wisconsin, and each one yields two handy and long-lived garden containers when split it in half along the red dotted line.

Heavy duty polyethylene sump liner

The bottom part of the sump liner--a container for a mini-bog

The bottom part makes a handy mini-bog for plants that like to grow with wet feet.  Around here, various water-reeds, Siberian irises and other famously thirsty plants grow in their own little bogs, created from the bottom part of the sump liner which has been sunk into an ordinary flower bed, then filled with soil.  I knock a drainage hole into the bottom, because otherwise the soil becomes anaerobic and smells and begins to kill the plant.  But, the hole is small: water stands in these for a few hours after a watering or a rain. Because the drainage is super-slow, make sure the plant you place into this truly does like wet feet.

With the right plant and this trick, you can now grow water-lovers right in a mixed bed, even in a dry exposed position.  Here are Siberian irises in a rather exposed and dry bed, but their own little feet are quite wet in their own mini-bog.

Siberian irises growing in their own
personal mini-bog.  I have partially marked the
outlines of the sump-liner
bottom with a red dotted line.

It's a trick worth knowing, if only to confound other gardeners.  This trick is even more confounding if the tub-edge is concealed with mulch like cocoa-hulls or shredded bark, or simply when the plant hangs over the edge, as with the thirsty ligularia below.

Ligularia "the rocket" needs a LOT of water,
and could not ordinarily grow in this dry shaded
area, where it has to compete with tree roots
for water.  However, nestled in the bottom
of a cut off sump liner, it has thrived in this
location for years. 

The top part of the sump liner--a tube for potato production via compost-hilling

After the bottom part is cut off, you are left with a sort of a tube.  This is a very handy item for growing potatoes via the compost-hill method.  What you do is, place a seed potato into the ground, maybe a few inches deep--no need to dig further.  Place the tube on top, cut side up, then cover with a few inches of old leaves from winter clean-up. When the potato plant comes up, add mulch around the potato stem, packing it in pretty well, but not so firmly as to injure the stem.  Eventually, you'll have the entire tube filled with mulch and the potato plant will be peeking out of the top.  When ready to harvest the potatoes, lift the tube up, and there will be a LOT of potatoes waiting to be eaten with no particular digging on your part.  The tube is sun-proof and very dark, the plant spreads over the top, so there is very little greening on the potatoes in the tube.

As great as the potato trick is, there is a second and possibly bigger advantage to this system. I put these tubes into the flower beds, generally on a bare spot where some perennial didn't make it through the winter, or sometimes, where an invasive plant is sprawling beyond its limits.

A peek at the mulch within the tube.  As
the plant grows, you add mulch to keep
burying the stem.  More potatoes form along
the stem, and harvest is very easy: simply
remove the tube. 

As I generate organic waste (by clean-up, or weeding or thinning or digging around in the flower beds) I simply dump the waste into the tube, as you see above.  This two-in-one system provides the mulch with which to bury the potato-stems as they grow, while also providing a convenient compost pile right in the flower bed--I don't have to go very far with each load of material.

As for the sprawlers which are overreaching themselves, I thin them out by situating a potato-tube right on their heads.  They die back under the tube via a combination of pulling out their stems + the waste thrown on their heads + a potato growing on top of them.  Below is a photo of an overgrown stand of garden phlox getting the thin-out treatment via a potato hill plopped down right in the middle of their overgrown patch.

This tube of potatoes is helping to thin an
overgrown phlox bed: the tube was plopped down in the
middle of the phloxes.  My only contribution to the thinning
process will be to periodically snap off the phlox trying to grow
inside the tube, then adding the stems to the compost inside the 
bucket.  No digging will be required. 

One does have to be a bit selective with the stuff tossed into the tubes: a weed gone to seed would be a poor addition to a compost pile right in a flower bed: the small size of the tube means the compost never heats up--a good thing, or it would cook the potato-stems.  Yet, no heat = viable seed.

Therefore, the sort of compost which goes into these tubes must be seedless, such as leaves from winter clean up and soil-covered root balls, and green stuff like cut-back stems--what I call "organic bulk materials."  Seed-headed weeds and invasives like sedum go into a black plastic garbage bag, to cook in the sun for a few weeks, and THEN into the tube.  (Yes, in the paths of my flower bed, there are black plastic garbage bags--mostly tucked away out of sight because the bed-paths are curved, but undeniably, there are garbage bags out there--you can see one on the extreme right edge of the below photo.)

The black hides well in the garden, don't you think?

Being black, these sump liners really kind of hide in the garden, and a potato plant peeking out of the top adds architectural height to an otherwise flat bed: it's an ornament, really (or so I tell myself) and a darn good way of getting rid of garden waste.

This potato-tube system rotates annually. By the next spring, with the tube removed and the potatoes long gone, the pile of organic material will have nearly disappeared, but there will remain a little hillock of compost-improved soil, which will handily support a new-transplanted perennial into the bare spot. Sadly, after the winter, another bare spot is sure to have opened elsewhere in the garden as some other perennial expires of cold, or old age or sheer cussedness.

To sum up: in this cycle, a crop of potatoes is grown, while the soil on an otherwise bare spot is improved after the tube is moved and then the system started over again. The cycle for any one bare spot ends when a new perennial or division is put into the improved soil left behind where the potato tube was situated the previous year.

As to durability, these sump pump liners are meant for years of continuous ground- and water-contact.  I have some which have been in the ground for a decade, and they show no sign whatsoever of wear.

Sump liners for the win!

Good gardening--TK