Like gardeners elsewhere, local gardeners like to get a jump on the season by planting tomatoes before May 1, the average date of the last spring frost. However, because tomatoes are warm-season plants, early planting with frost protection does not necessarily lead to an earlier harvest. Tomatoes need warm soil and air temperatures to grow and prosper.
The needed heat can be provided with Wall O’ Water plant protectors or similar water wall devices that consist of a cylinder of tubes made from translucent plastic sheeting. When the tubes are filled with water, they create a “wall of water” around the plants. Sunlight heats the water up during the day and that heat is released to the soil and air around the plant at night.
Today's stories delivered to your inbox Click here for the Tri-City Herald’s daily morning and afternoon email newsletters
Many avid gardeners use Wall ‘O Waters, or similar products like Kozy Koat Water Teepees, for getting a head start on the tomato season. However, gardeners often complain that it is difficult to fill the devices.
Instructions say to place the cylinder over an overturned or upright 5-gallon bucket, and use a hose to fill the tubes. Once the tubes are filled, the approximately 20 pound device is lifted off the bucket and placed where a tomato will be planted.
The process sounds simple, but gardeners find it hard to accomplish it without getting their feet wet or tiring their backs.
After researching a better way and not finding one, I brainstormed. I put the empty device inside a 5 gallon bucket and filled up the tubes. This was easy to do while sitting in a chair and without getting my feet wet. I then used the bucket to carry it to where it was needed and lifted it out of the bucket. It worked like a charm. Let me know if you have an easier way to fill up Wall ‘O Waters.
Local gardeners who use water wall devices have two other tips. One is to make sure the walls are secure when placed in the garden or they may blow over in winds. This can be done by placing one to two stakes inside the device when setting them in the garden. Some gardeners secure them with wire tomato cages inside or outside the cylinders, but watch for for wire ends that can puncture the tubes.
The other tip is to remove the devices when daytime temperatures are regularly above 80 to 85 degrees because the temperatures inside the walls will be higher and can climb enough to damage the plants. Removal before the plant gets much taller than the cylinders is advised because they are difficult to remove later without injuring the plants.
Are these water wall devices worth the trouble and expense? One university study showed that the use of the devices can decrease the time to harvest of the first ripe tomato by about 10 days, and less-expensive waxed paper hotcaps can reduce the time to harvest by 6.7 days. Interestingly, homemade covers made from plastic milk jugs actually increased the time to harvest by 5 days.
A study in Madras, Ore., showed that there was no significant difference in the date of first harvest between tomatoes planted a month early in water wall devices and those planted directly in the garden a month later. However, the total yield of ripe tomatoes for the plants grown initially in the wall devices was about eight times the yield of those planted later with no protection.
Marianne C. Ophardt is a horticulturist for Washington State University Benton County Extension.