You may have noticed that I painted the tubes different colours, one set green and the second set red. For the 10 tubes, odd numbered ones are red and even numbered are green. "Half" of each also have different soil mixes in them, so I have two experimental conditions .... not ideal really but I needed to eliminate some conditions pretty quickly. I did start with four types of mixes but two of them, as I noted earlier, quickly showed how poor they were at water retention. The main difference now is one set uses peat and compost and the other uses wood based soil amendment and compost.
Initially the apple green was for visual appeal, and to reduce the photodegredation of the pvc plastic in the sun. It also went nicely with the red of the house and other woodwork we have. When you are in an urban environment looks matter.
Before I planted them I had recalled some research on the impact of red mulches on fruit production, which had indicated a slight increase in productivity. Thanks to Gena Moore, the Organic Research Coordinator at Carolina Farm Steward Association (a place worth supporting and as a consultation group), she found one of the original sources for my memory. Yes, I know it applies to tomatoes, peppers and cantaloups but .... in general it seems a potential MINOR increase in production. It also seemed to make a difference in terms of the product used. Now since I am using a latex paint it might be a little more ambiguous, but I did then find an older publication for strawberries which showed improvements in taste and sugars with a red plastic mulch.
After one week of harvesting every two days, I'm still not clear on any potential improvement in fruiting or taste. The biggest struggle has been keeping all my strawberry plants alive and fruiting in the unseasonably hot week we just had. In the end I actually lost a few plants that I had in the ground, but not ones in the towers. Basically, with a easy to use drip irrigation for the towers it was simple to keep them hydrated turning it on every two days. Whereas some of the smaller, younger plants in the new beds I created got fried .... and died. The other potted strawberries also struggled a little more, had to water them twice a day to keep them alive.
Marnie LOVES the towers. No bending to pick the strawberries and the fruits are much cleaner. So, even if they do turn out to be a little less productive per plant I know where she will be coming down on this experiment (more towers please!!!).