How to Grow Flowering Trees in Containers

Growing a tree from a shrub is a botanical impossibility, but a skilled horticulturist can create the next best thing. “Tree form” is the term used to describe a shrub that is shaped to look like a tree. After carefully pruning and training a flowering shrub — a process that typically takes several years — the end result is an eye-popping plant that will turn heads and stop traffic as people pass your yard. And if you tweak it another notch by growing this flowering “tree” in a container, you’ll raise it above the soil level so it commands even more attention…plus you won’t have to dig a single hole!

Up Close and Personal

If you enjoy bringing fresh-cut flowers into your home, you’ll love tree-form shrubs. No more bending down, losing your balance and even risking a fall just to cut your flowers — these “flowering trees” bring your flowers up to eye level where you can easily snip the blossoms. And if you plant fragrant flowers, you won’t even have to bend down to enjoy their fragrance, because the blooms are raised to “nose level!”

Roses

Of all the different kinds of roses you can choose for growing in containers, you cannot go wrong with Knock Out® Rose Trees. Their sheer beauty, stunning colors, sweet fragrance, long bloom season (up to nine months) and resistance to pests and disease make them the hands-down choice. (Zones 5-10)

•   Red Knock Out® for a vibrant accent.
•   The irrepressible Sunny Knock Out® for a cheerful yellow splash.
• Use a grouping of three containers by sandwiching a Red Knock Out® between Sunny Knock Out® (or vice versa) to make the colors really pop.

Gardenias

Pure-white blooms that exude an intoxicating fragrance to permeate your garden make gardenias a sensory garden staple. It’s also the perfect plant for a moon garden — white blossoms that reflect the moonlight and perfume the night air. But any old gardenia just won’t do for your “flowering tree.”

• August Beauty Gardenia (Gardenia jasminoides ‘August Beauty’) is renowned for its longer-than-usual bloom time — you’ll enjoy its flowers from summer through fall. (Zones 7-9)

Hydrangeas

Panicle hydrangeas put a delightful spin on the old-fashioned mophead types. Oversized, cone-shaped blooms are borne in profusion on sturdy plants that scoff at some of the problems other hydrangeas face, such as pests, diseases and inclement weather.

• Limelight Hydrangea tree (Hydrangea paniculata ‘Limelight’) bears hard-to-find lime-colored flowers in spring through summer that turn blush-pink in autumn. (Zones 3-8)
• Vanilla Strawberry Hydrangea tree (Hydrangea paniculata ‘Renhy’) looks like luscious strawberry syrup drizzled on vanilla ice cream. Your neighbors will not believe this is a hydrangea. (Zones 3-9)

Some Container Tips

• Choose a container that’s large enough and heavy enough to balance the top growth of your flowering tree.
• Make sure the container has drainage holes. Some “ornamental pots” have punch-out places at the bottom for you to make the drainage holes.
• Use a soilless potting mix that’s formulated for container plants, because sometimes your garden soil may compact too heavily in a confined space.
• The soil in containers will dry out faster than the soil in your garden, so keep your containers well watered, particularly during hot, dry summers.
• Be mindful of your particular plant’s sun or shade requirements, and place its container in a spot that captures the appropriate light level to keep it thriving.

Hardiness Zone Allowance

Plants in containers are raised above the grade of soil, so their roots don’t have the benefit of being insulated by the ground. This is a simple fix. All you have to do is shift the coldest limit of your actual zone range to one zone warmer. For example, if the coldest range of your climate is hardiness zone 4, choose a plant that’s hardy to zone 5 as the guideline for its cold hardiness in a container.