When purchasing a new plant, it almost always comes encased in a thin, flexible plastic nursery pot designed for temporary containment and transport. The question of whether to leave this container on the root ball before planting is common for new gardeners. The definitive answer is that the plastic pot must be removed before planting. Leaving this temporary vessel in place will significantly compromise the plant’s long-term health and growth.
The Essential Rule of Transplanting
The plastic pot acts as a physical barrier, preventing the plant’s roots from expanding naturally into the surrounding soil. For a newly transplanted specimen to thrive, its roots must immediately establish contact with the garden soil or new potting mix. This contact allows the plant to anchor itself and begin drawing water and nutrients from the larger environment.
Since the plastic is non-porous, it creates an impermeable division between the root ball and the surrounding earth. Roots unable to penetrate the barrier cannot access the moisture and mineral resources outside the original soil mass. This failure to integrate the root system stunts the plant’s ability to settle in and grow successfully.
Long-Term Consequences of Plastic Barriers
Leaving the plastic pot in the ground creates biological failure points that become more severe over time. The most damaging consequence is root girdling, where roots are forced to circle the inside perimeter of the plastic wall. As the roots thicken, they strangle each other and compress the plant’s vascular system, inhibiting the flow of water and nutrients between the roots and the foliage.
Water absorption is also negatively affected because the plastic barrier interferes with normal drainage and soil capillary action. Water tends to run down the sides of the plastic, wicking away from the root zone, or pooling inside the container, which can lead to root rot. Furthermore, the plastic itself does not decompose; it remains a permanent obstruction to healthy root development and soil ecology.
Addressing Rootbound Plants
Plants that have been in their nursery pots for a prolonged period often become rootbound. This state is visually identifiable when the roots are tightly matted and have taken the circular shape of the container. If a plant is severely rootbound, simply removing the pot is not enough, as the circling roots will continue to grow inward rather than outward into the new soil.
To correct this, the compacted root ball must be physically manipulated to encourage new outward growth. Using clean shears or a knife, make several shallow vertical cuts, or “scores,” down the sides of the root ball, and an “X” or slices across the base. This process is necessary to sever the circling roots and stimulate the growth of new, straight roots. After scoring, gently tease the roots apart with your fingers, pulling them downward and outward. This action disrupts the established circular pattern, ensuring the roots grow away from the stem and establish a stable foundation for future growth.
Handling Biodegradable and Fiber Pots
Pots made from materials like peat, coir, or paper pulp are often advertised as plantable. While these materials are designed to break down, they still require attention before planting. The main risk is that these containers can wick moisture away from the root ball, causing the soil inside to dry out faster than the surrounding earth.
To mitigate this wicking effect and speed up decomposition, it is recommended to tear off the rim of the pot so it sits below the soil line. For denser fiber pots, lightly tearing the sides or making a few shallow vertical cuts helps the roots escape more quickly. Ensuring the entire biodegradable pot is covered by soil is also important, as exposure to air can significantly slow the breakdown process.