We have been successfully using Wall O Water plant protectors (here’s our extensive review) to increase our vegetable harvest in our cold climate and our extremely short growing season. Over the years, we have discovered some simple tips to help them work better.
Do Not Completely Fill Wall of Water Cells
If the cells are completely full, the top of the Wall of Water is wide open. Sure, more water provides more protection against the cold, but not if the top is left wide open. If the cells are about 2/3 to 3/4 full (12-14 inches from the bottom) the base can be spread out and the top will lean toward the center and in effect pinch the top shut. This helps keep the cold air out. Less water also helps lower the center of gravity and that helps prevent the wall of water from collapsing.
Use Stakes to Support Wall of Water so they do not Collapse
In the past, the Wall of Water has collapsed and damaged our plants. To prevent this, place two stakes at opposite sides of the Wall of Water at angles as shown in the photo. One stake is better than nothing if placed against the wall that has the most tendency to lean.
We use rebar instead of wood, because most wood stakes have splinters that could puncture the wall of water. Smooth wood should be fine. Very rough rebar, especially sharp ends could also cause leaks. PVC pipe would also be used as stakes, or it could be use to cover the rebar.
Note: Notice in the photo above, the exposed tips of at all rebar stakes have been covered with pieces of flexible hose. This is to prevent injury. Rebar can cause serious injury if someone were to fall onto a rebar stake or bend over and poke a rebar stake into an eye.
Tie the Top of Wall of Water Closed on Coldest Nights
On nights that are predicted to be below freezing, we tie the tops closed with string. Next morning after the temperature has warmed up, we remove the strings to allow better air circulation. We hang the strings on the stakes so they are readily available to slip back over the tops for the next cold snap.
Drain and Dry Wall of Water for Winter Storage
Algae will start growing inside the cells. I am sure bleach would kill the algae, but you wouldn’t want it on your plants and it might cause the plastic to deteriorate, so don’t bother. Simply let the Wall of Water drain and dry completely at the end of the growing season before you put them away for the Winter. I turn them upside down over rebar or other stakes or hang them upside down with clothespins. By spring, the algae is a dried crust that easily washes out in the Spring when they are refilled.
Fix Cells in Wall of Water that Leak
Over time, some of the cells will begin to leak. Some of ours even have large holes, but that is due to carelessness and mistreatment. Don’t walk on them!
Replacement cells can be purchased to fix cells that leak, but for the price, I prefer to sacrifice an old Wall of Water that has more than one leak.
A three pack of Walls of Water only cost about $15 or about $5 each depending upon shipping or how much gas you use driving around trying to find them. The replacement cells are about $6 for six cells or about $1 each, so sacrificing a wall of water costs about 55 cents for each cell. Every other cell (9 cells) can be used for a replacement cell. Just make sure to identify all the leaky cells and make the first cuts through those cells.
To make replacement cells from an old Wall of Water:
- Cut completely through two cells on each side of cell to be used
- Trim the plastic on the outside of the seams on each side of the cell as possible
- Push the trimmed replacement cell down inside the leaky cell (I use short piece of PVC pipe)
- Fill the cell with water (easy to pour water through the PVC pipe).