A Gardener's Guide to Plant Container Types: What to Know Before You Buy

Plants grown for gardens and landscape projects usually arrive in one of four forms: plastic pots, biodegradable (cardboard or fibre) pots, balled-and-burlapped stock wrapped in burlap and wire, or bareroot. Each has its advantages. Here is how to choose when you're buying your plants and have the option.

Plastic pots are the most common format for annuals, perennials, shrubs, and sometimes trees. These are usually started in greenhouses and stepped up into larger pots as the plant grows. Because they are raised in a controlled environment and in close quarters, the plant doesn't reach its full natural spread, but it is also regularly fertilized and sheltered from the elements. As potted plants mature they often become root-bound, which you'll see as a mass of roots circling the inside of the pot when you slide the plant out. These are well-established plants that transplant with relatively little shock and settle happily once their roots can spread into open ground. If a plant is heavily root-bound, gently tease the outer roots loose with your hands before planting so they grow outward instead of continuing to circle. Trees grown in larger plastic pots establish quickly and with minimal transplant shock, though they can be less full than field-grown trees and usually need staking until their roots take hold.

Cardboard and fibre pots are a more environmentally friendly potting option offered for some perennials and many shrubs and trees. The material is biodegradable, so the plant can go into the ground in its pot. Before planting, tear off the top rim so it doesn't sit above the soil and wick moisture away from the roots, and open or score the sides to help the roots push through. If the plant looks root-bound, remove the pot entirely. Like plastic-grown stock, these plants are raised in controlled conditions, with the added benefit of far less plastic waste.

Burlap and wire (balled-and-burlapped) stock is typically used for larger field-grown shrubs and trees. These are grown outdoors to size, then dug in spring and wrapped, with the rootball held in burlap and a wire basket. Set the plant in the hole first. You could cut away the top third of the wire basket or leave it in the hole. It doesn't need to be removed. Remove all the twine and any plastic string. Peel the burlap back from the top of the rootball; untreated burlap will break down, but synthetic or treated burlap should be removed. Because they have grown outdoors through the seasons, these plants tend to be hardier and fuller than a potted equivalent. They do lose some roots when dug, so expect a degree of transplant shock and should be watered regularly until established.

Bareroot plants carry no soil and are lifted in late winter or very early spring while the plant is still dormant, which keeps shock to a minimum. Berry bushes, fruit trees, roses, hedging and some native trees are commonly sold this way. They are the least expensive option, but their roots have been through a lot, so soak them in water for a few hours before planting to rehydrate, and get them in the ground before they begin to leaf out. Bareroot is most worthwhile when you're buying in larger quantities, where the lower cost and easy transport really pay off.

Happy planting!