When Mrs Freedom wanted strawberry towers in our backyard garden to explore a bit of vertical gardening I of course searched the interwebs for what others have done in this regard as we all know there’s no original thoughts or actions left to be had. See what everyone else does, follow a simple online tutorial, and we’d be up and running in no time. What I found is it’s nearly impossible to find garden strawberry tower options that don’t involve PVC in the discussion. It’s the de facto material of choice. So is it safe for use in your garden?
Mrs Freedom experiences a myriad of complications due to Lyme Disease so she has to be careful to avoid environmental contaminants whenever possible and the words ‘organic’,’non-GMO’ and ‘no preservatives’ get used with regularity in our home. Besides, it’s just the right thing to do. Seeing as we want to actually eat our strawberries and our son can only eat organic strawberries or he reacts them, we wanted the safest option we could find.
With this in mind I did some online investigation of the safety of PVC (white) and ABS (black) plastic plumbing options related to human food consumption and toxicity. What I found sounded pretty definitive for ABS (black) plastic – it is toxic and should be avoided for all food production and potable water. Researching ABS was less definitive but raised enough questions and doubt for me to want to find a less toxic option.
Perusing the local hardware store for options the only thing that seemed to meet my requirements of non-toxicity and reasonably easy to work with was untreated-lumber. Pine is cheap but not very durable, treated lumber is more water resistant but has the potential to leach chemicals like plastic can, and then I arrived at cedar. Durable and water resistant similar to treated lumber, beautiful to look at and smells great, and not as expensive as I expected in the small sizes I needed. About 30% more than the cheap pine.
How To Guide
Materials and Tools needed:
- cedar lumber – 1 in x 4 in x desired height (need 4 of these). I got 8 feett long which is enough for two towers in the height I desired.
- screws; coated so they won’t rust – at least 12 per tower. I used No. 8 x 1 1/4 inches long with countersunk heads so they will lay flush against the boards.
- tape measure
- screwdriver, preferably power
- hole saw – recommend range of 1.5 to 2.5 inch diameter. I used 2 3/8 inch diameter.
- small drill bit for drilling pilot holes for screws in wood. I used a 1/16 inch bit.
- power drill
- Not shown in photo:
- hand saw
- soil ingredients
- strawberry plants
I made two towers and wanted them to be slightly different heights for visual interest. The wood length I chose was 8 feet so I cut each of the four pieces to a length of almost 5 inches from the center which resulted in about a 10 inch difference in height for each of the two towers. The total height of each tower is then about 43 and 53 inches, keeping in mind that a portion of the bottom of each tower will need to be buried in the ground (I did about 10 inches) and they will not stick up quite this high. Also, I opted to not have any plant holes lower than 10 inches above ground level to make it harder for insects to get at them.
Measuring, Cutting, and Fastening the Cedar
Mark with pencil and tape measure and cut the cedar boards to the desired length with saw.
Once you have sets of four boards the same length you can start attaching them by taking two and overlapping them along one long edge. Use drill and pilot drill bit to drill a pilot hole for the first screw about 6 inches from one end of the boards. Be sure to align the hole so the bit will go straight through the top piece and into the middle of the board behind. The pilot hole greatly reduces the chance the cedar will split when the screw is driven in.
Keeping the boards (and the pilot hole) aligned, use your screwdriver to insert a screw in the pilot hole. Continue until the head is flush with the board. Drill another pilot hole about halfway down the board the same manner as the first and add a screw and then one more pilot hole and screw at the far end of the board from the first hole again about 6 inches from the end.
With two of four boards now secured continue with pilot holes and screws in the same manner for two more boards until you have created a long square-profile cedar tube.
Drilling Holes in the Cedar
To begin drilling the big holes choose a side to start on and measure about 4 inches or more from end board end to the center of the hole saw. Be sure to center the hole saw not in the middle of the board as each board is offset from the center of the whole structure.Position the center of the saw so it will create a hole that is centered on the inside of the structure when you drill all the way through the wood.
After drilling holes removing the wood disc that remains inside the hole saw can sometimes be trying so some patient use of a screwdriver or similar object to poke it out is necessary.
You will need to choose how many sides of the structure you wish to drill holes into. I chose two sides that predominantly face the sun throughout the day. You may opt for 1, 2, 3 or 4 sides depending on your needs and taste.
For spacing the holes it works best to have them staggered at least 4 vertical inches between holes. It is not recommended to drill holes on different board faces that align with each other because when the plants are inserted their roots will all be vying for the same soil and limit their potential growth.
It is recommended to leave about 20 inches at the bottom of each tower with no strawberry plant holes. 10 inches to be buried in the ground and then a gap of about 10 inches to the first hole. This allows the plant that goes in the bottom hole to hang down without touching the ground to avoid giving insects easy access to eating your strawberries before you do.
Installing the Cedar Towers in Your Garden
Pick a location to mount the strawberry towers that offers lots of sun, a convenient method of watering (manual or automatic) and that will show off those beautiful strawberry flowers and berries once they come in. Dig a hole about 10 inches deep that is slightly bigger than the tower base, insert the tower into the hole and pack the dirt back in around the base nice and tight until the tower feels reasonably secure and will easily stand on its own.
Adding Soil and Strawberry Plants
Mixing fertile soil is an entire topic of its own. The short version is combine some Sea Soil or similar with peat moss and ideally some compost and bone meal. Mix in a wheel barrow or bucket. Use your hands or a small shovel or trowel to load the soil into the top of each cedar strawberry tower. Stop at the bottom of the bottom hole.
Remove a strawberry plant from the container it came from the store in and keep all the soil and roots intact. The soil and roots may be larger than the cedar hole so you’ll need to massage it into the hole trying to disturb the root ball as little as possible. Make sure to get the entire root ball inside the cedar tower. Then continue to add soil to the top of the tower so it falls down and fills up the tower to the bottom of the next drilled hole. Repeat the process of adding strawberry plants and soil in this way until all the holes have plants in them and the tower is full of soil to the top. The soil can be compacted slightly so water won’t wash it away so easily but do not pack it too tight.
Watering the strawberry towers is as easy as using your favourite watering container to gently pour water into the soil at the top of the towers. It will take a bit of time for the water to filter down to the lower plants but gravity is relentless so it will eventually get there. Be aware that if you feed water too quickly it will start to drain or pour out of the upper plant holes and wash the soil away. Go slow and let it seep down.
Optionally, I have an automatic watering system in my garden so I added the towers to that system. If you have a garden and are still hand watering I highly recommend exploring automatic watering systems with electronic timers. It took some planning and a modest expense initially but it’s been running reliably for 7 years and Mrs. Freedom is extremely happy with it. In my case I added drip emitters that are rated to drip water at a rate of 1 gallon per hour. I run the timer for about 30 minutes daily which works very well and drips slow enough that it does not wash soil away and all the plants get adequately moistened.
Now enjoy the fruits of your labor!