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Potted Holiday Trees: Selection and Care

Potted Holiday Trees: Selection and Care Featured Image

Small or large potted holiday conifers are fragrant, fresh and provide living beauty in the home, but which should you choose for outdoor planting, and how do you care for them after the lights and glitter are shed? The right care will ensure their longterm health. Here’s how to give them what they need for success.

Know Your Trees

When picking a live tree, know what kind it is, and make sure that it will fit into your landscape and grow well where you live. Don’t be fooled by the initial size. Many potted trees sold as tiny specimens grow very large. Truly compact trees sold during the holidays, such as dwarf Alberta spruce (Picea glauca ‘Conica’, USDA Hardiness Zones 3-6) or lemon cypress (Cupressus macrocarpa ‘Wilma’, Zones 7-10), can be planted in large, outdoor containers for several years. But, those that mature to a large size must be planted in the ground. So, you must know your trees.

Miniature Christmas trees with ornaments
Beware! Many holiday trees sold as potted miniatures will grow very large.

Here are some of the top holiday trees sold in North America. Each grows best in certain areas of the country. All of the full-sized evergreens mentioned need lots of space, sunshine, and well-drained soil.

Firs

Potted fir trees
Be sure to have a planting spot in your landscape for larger potted trees.

Chrismas firs have soft, flat needles, a perfect conical shape, dense branching, and wonderful wintery aromas. They make good landscape specimens, where they are hardy, and all grow to become large, regal trees.

Balsam fir (Abies balsamea, Zones 3-7): The remarkably hardy balsam fir is a fragrant, soft-needled evergreen that grows best in colder climates with cooler, more moderate summers. It has a dense, conical habit and standard forms can reach a whopping 50 to 75 feet when fully mature, so don’t plant one in a small yard or close to the house.

Frasier fir (Abies fraseri, Zones 4-7): Comparable in growth, habit, and fragrance to balsam, Frasier fir is an Appalacian species from the southeastern United States that can take warmer summers, but because it grows in the cooler mountains it cannot take the intense heat of the Deep South. At full size, it reaches 30-50 feet.

White fir (Abies concolor, Zones 4-9): A fir for the Midwest and alpine West, white fir is more tolerant of areas with warmer summers. It has a conical habit with dense branching and soft, attractive, upright needles with a silvery cast. When mature, it can reach up to 60 feet.

Douglas fir (Pseudotsuga menziesii, Zones 4-8) is not a true fir, despite its name, but the pine is a good choice for those living from Pacific Northwest down to the Southwest. Soft-tipped needles cover its branches and when grown as a specimen tree it reaches 40-80 feet and has a broadly conical habit with more open branching than that of true firs.

Pines

Potted Christmas tree inside a home
Potted Christmas trees should be well watered while in the home.

White pine (Pinus strobus, Zones 3-8) is one of the most common native pines grown for Christmas trees. It is distinguished by its long, very soft needles, which some homeowners really favor. It makes a good landscape tree with open branching and can reach 50-80 feet.

Scots pine (Pinus sylvestris, Zones 3-7) is still sold but has fallen out of favor as a Christmas tree because of its painfully prickly needles. As a yard tree, it is equally undesirable because it’s prone to many pests and diseases. This is one to avoid.

Spruces

Dwarf Alberta spruce (Picea glauca ‘Conica’, Zones 3-8) is the most common potted holiday tree and is almost always sold as a pre-decorated, miniature for indoors or outdoors. After the holidays, it can be planted in pots for or in the garden. Eventually, dwarf Alberta spruce can reach 10 to 13 feet high but is very slow-growing, so it can be grown in pots for some time before planting in the ground.

Indoor Care and Transition

Christmas Tree
Indoor conifers should be kept inside no more than ten days.

All of these evergreens need cold winter weather to grow well, so bringing them into the warm indoors for too long can be detrimental to their health. Keep them in a cool garage or covered patio before bringing them inside. Once indoors, make sure that you place a basin below the pot for watering and keep the tree well-irrigated. Maintaining a cooler room temperature will reduce stress. Don’t keep them inside any longer than ten days, a week is better.

After the holidays, remove all decorations and take your tree outside. Very hardy varieties can remain in their pots if kept close to the home. Just don’t let the pots dry out. If the ground is warm enough to be worked, plant your tree straight away.

Planting

Getting ready to plant a potted evergreen
Getting ready to plant a potted evergreen.

All of these conifers like their soil to be slightly acid, rich in organic matter, and well-drained. Black Gold Canadian Sphagnum Peat Moss and Fafard® Premium Natural & Organic Compost are the best amendments to use at planting time. (Click here for the Morton Arboretum’s tree-planting instructions.)

Potted holiday trees are a long-term investment. While they decorate your home and bring joy to your family, care for them well. And, once planted, they will reward you with continued outdoor beauty for years to come.

Pruning Hydrangeas

Pink big leaf hydrangeas
Prune mophead bigleaf hydrangeas in summer just after blooming.

Timing and method are essential when it comes to pruning hydrangeas, and they differ depending on the species being pruned. If done improperly, you may prune off next year’s flower buds or cause your shrubs undue stress. On the other hand, making the right cuts at the right time will help keep them looking great and flowering to perfection.

Good Pruning Technique

The right techniques and tools are key to good pruning. Here are the basics.

The Best Pruning Tools

Sharp loppers, hand pruners, and hand saws
Choose sharp loppers, hand pruners, and hand saws for easy pruning.

For small branch cuts (up to 1 cm thickness), choose a quality set of sharp bypass pruners (avoid anvil pruners, which dull quickly). Bypass pruners are easy to sharpen and long-lasting, if you choose a high-performing brand (I like Felcos). For larger branches (up to 4.5 cm thickness), choose sharp bypass loppers. More powerful pruning tools may be needed for large panicle hydrangeas that become tree-like. For larger cuts, opt for a small, sharp pull-stroke pruning saw to cut through tough branches in no time!

How to Prune

Making the right cuts to branches will facilitate good plant health. Cuts to small branches should be made 2/3 cm from the adjacent stem. Make them at 45-degree angles. Larger branches should be cut flush to the trunk collar. The collar is the ripple of bark that will slowly and protectively grow over the cut. Cuts made above the collar will not heal properly, leaving plants vulnerable to pests and disease.

How Much to Prune

A stem with a 45-degree-angle cut
Make 45-degree-angle cuts 2/3 cm from the adjacent stem. Don’t damage lower buds!

Prune to the desired height, but beware of over-pruning. Refrain from pruning over 1/3 of the top growth, especially in smaller shrubs with well-branched woody top growth. Some species, such as smooth hydrangea (Hydrangea arborescens), are clump-forming with stems that can be harshly pruned back if the clumps are well established and have become overgrown. Others, like panicle hydrangea (Hydrangea paniculata), can become tree-like and require more selective pruning.

When to Prune

Hydrangea pruning time is species-specific. Follow the following guide for the top four garden hydrangeas.

Pruning Bigleaf Hydrangeas

Purple hydrangeas
Mopheads have a rounder more formal growth habit.

Latin Name: Hydrangea macrophylla
Best Time to Prune: These hydrangeas bloom on second-year wood, so the best time to prune is in midsummer, just after they bloom. If you prune in later summer or fall, you will cut off next year’s flower heads. Deadwood is common, especially in spring. Dead or dying stems can be removed at any time of year. Old blooms can also be removed at any time, as long as you just remove the flowers and not the buds that have developed below them.

Blue big leaf hydrangeas
Pruning bigleaf hydrangea in fall will remove next year’s flower buds causing irregular flowering the following year.

How to Prune: These hydrangeas can grow too large or develop ungainly stems that have grown too high — shape plants by cutting wayward or old stems to the ground. Stems can also be trimmed to the desired height, depending on the density of the overall shrub. Refrain from shearing bigleaf hydrangeas if you want to maintain a more naturalistic, appealing appearance.
Comments: Bigleaf hydrangeas can have either lacecap (Hydrangea macrophylla var. normalis) or mophead flower clusters. Lacecaps have a looser more naturalistic horizontal growth habit and should be pruned less formally. Mopheads tend to have a rounder habit better suited to uniform pruning. In northern zones above USDA Hardiness Zone 6, these shrubs may die to the ground, so they will never flower. Protecting the crowns with Fafard Premium Natural and Organic Compost and straw can help protect their flowering stems from the winter cold.

Lacecaps
Lacecaps have a more naturalistic habit and require selective pruning.

Pruning Oakleaf Hydrangeas

Standard oak leaf hydrangeas
Standard oakleaf hydrangeas are tall, broad shrubs.

Latin Name: Hydrangea quercifolia
Best Time to Prune: Oakleaf hydrangeas also bloom on second-year wood and should be pruned just after blooming in midsummer. Once shrubs have leafed out in spring, identify and remove any dead wood from the previous year.
How to Prune: Some compact oakleaf hydrangeas have rounder, tidier habits but most reach 8-feet in height and develop a broad, naturalistic habit. Remove overgrown or crossing branches. If they overgrow an area, shrubs can be hard-pruned back by half in midsummer. Just be sure to leave plenty of green leafy branches for strong growth, and keep newly pruned shrubs irrigated through dry summer days to encourage new growth and bud set.
Comments: The pretty flower panicles of oakleaf hydrangea dry nicely and look good in winter gardens. Remove the old blooms in late winter to keep shrubs looking fresh in spring.

Dry flowerhead of oak leaf hydrangea
Keep the dry flowerheads of oakleaf hydrangea on plants for winter interest.

Pruning Panicle Hydrangeas

Panicle hydrangeas
Panicle hydrangeas are hardy and best pruned in late winter or early spring.

Latin Name: Hydrangea paniculata
Best Time to Prune: These tall, hardy hydrangeas bloom on new wood, so the best time to prune is in late winter or early spring. Remove ungainly or crossing branches and dead wood at this time. Refrain from summer pruning, and avoid removing more than 1/3 of the top growth at pruning time.
How to Prune: Panicle hydrangeas are variable shrubs that tend to be tall (8-15 feet) and bushy or tree-like, but some cultivars are compact for small-space gardens. Selectively prune bushy varieties, cutting tall branches to the trunk or base of the plant. Cut the large branches of tree-like varieties to the trunk, making sure cuts are flush to the collar.
Comments: These shrubs revive quickly from pruning. Tree-form plants may develop suckers from the base of the trunk. Keep these pruned off to maintain a single trunk. The dry blooms of panicle hydrangea also look good through winter but should be removed in spring.

Pruning Smooth Hydrangea

Incrediball™ Hydrangeas
Large-headed smooth hydrangeas, like Incrediball™, should be pruned to 1/3 height in late winter. (Image thanks to Proven Winners)

Latin Name: Hydrangea arborescens
Best Time to Prune: These easy-to-grow hydrangeas also bloom on new wood and are best pruned in late winter or early spring. They respond well to harsh pruning and can even be pruned to the ground if they outgrow a space. By late spring, they will have grown back with vigor. Refrain from summer pruning.
How to Prune: Pruned these bushy shrubs uniformly to keep their habit rounded. Large-headed varieties, like Incrediball™, are top-heavy and appreciate regular pruning to 1/3 height to keep stems shorter and sturdier. Refrain from pruning large-headed varieties to the ground.
Comments: The bushy dry flower heads look great in winter but should be removed by spring. These hydrangea root very easily from cuttings. Take any pruned branches, dip them in rooting hormone, stick them in the ground, and keep them evenly moist. They will root in no time!