One of the most important things to remember when using plastic containers as planters is to drill holes. You don’t want too much water to collect in the container. Holes will allow excess water to drain out of the container. This is especially important if you keep the container outside. The excess water, if left in the container, could cause root rot.
I planted my cucumber plants in this container.
What Is Root Rot?
Root rot can have two sources — one is a prolonged exposure to overwatered conditions that can cause some of the roots to die back due to a lack of oxygen. As they die, they can start to decay or rot away. The rot can then spread to healthier roots and kill them as well, even if the soil conditions are corrected.
Read more at Gardening Know How: Treating Root Rot