Growing Trees In Pots

Growing trees in containers is a great way to add height and interest to a small garden, deck, or patio. The list of eligible trees is long, with virtually any tree under 8 feet tall being a candidate for containers. Citrus trees, palm trees, dwarf conifer, and broadleaf evergreens are great options. As long as the container you have is large enough to counteract the heaviness of the mature top growth, a container-grown tree can thrive for many years.


Planting Trees in Pots

The best time of year to plant in containers is early in the spring. If you will be growing a tree considered tender in your climate, wait until the nighttime temperature is above 50 degrees F before potting it or bringing it out of the house from the winter. Research your tree's growing needs and ensure that it will be placed in enough sun or shade as required. Planters for trees should be large from the start, as the root ball of a tree is always at least 1.5 times the diameter of its canopy. Select a container with at least a 16-inch diameter, with a large depth for taller trees. Weatherproof pots made of resin or plastic are lightweight and last for much longer than ceramic in climates with harsh winters if the tree remains outside throughout the year. Ensure the bottom of the pot has excellent drainage. 

Best Soil For Trees in Pots

Standard bagged potting mix that is soil based is fine for most trees in containers. Use soil designed for acid-loving plants if growing conifers or broad-leafed trees. Adding perlite will help keep the mix lightweight and free draining. Lightly mulch the surface of the soil to keep the soil moist longer, reducing the need for watering, especially during the summer. Use 1-2 inches of finely shredded bark or arborist chips, keeping it away from the tree trunk and root flare. 

Caring For Trees in Planters

Trees growing in planters require more maintenance than those growing in the ground. The gardener has to periodically replace nutrients in the soil leached out through regular watering. Regular watering is required since the roots are confined to a pot and unable to search for moisture on their own. Potted trees are also more susceptible to damage from cold weather and drying winds, and may require extra protection in winter. 


Watering Trees in Pots

Trees in pots will be in larger containers than most plants. Larger containers tend to dry out much slower than smaller ones, even in summer. The amount of water needed to keep a tree thriving is an easy calculation, and it increases each year as the tree increases. Allow 1 inch of water per inch diameter of the tree's trunk. So if the tree is 2 inches in diameter, it will require about 2 inches of water a week to thrive. The top 4-6 inches of soil can be allowed to dry out in between waterings.

Fertilizing Trees in Pots

Fertilizing is not often needed for trees growing in the ground because the roots can seek nutrients in an almost endless area. Trees in pots have a limited supply of nutrients that are leached out of the soil every time the tree is watered. Apply an extended-release, balanced fertilizer early in the spring to supply nutrients to the soil all season. Sprinkle it on the soil and water it in well, making sure to keep the dry fertilizer off of the foliage.

Winter Care For Trees in Pots

Trees suitable for your growing zone and climate should survive your winter climate. If the container is in an exposed location, such as a rooftop or windy hillside garden, extra care may be needed to insulate the roots or protect the branches from drying winds. Often growing plants that are one to two zones hardier than your USDA growing zone is the easiest solution for exposed gardens. Wrapping the containers in burlap or horticultural fabric also insulates the pot and the root system of the tree.


Growing Trees Indoors

Trees considered tender for your climate (think citrus, palms, or other tropical trees) may need to be brought into a frost-free or warmer spot for the winter. Many tropical trees can be grown as houseplants that take summer vacations. Ensure that any indoor tree is brought inside before nighttime temperatures fall to 50 degrees F. Try to provide as much sunlight as possible while the tree grows indoors.