There is nothing quite like a weeping blue atlas cedar (Cedrus atlantica ‘Glauca Pendula’). If the sculptural form and cascading branches don’t stop you in your tracks, the gray-blue color of the foliage certainly will. A perfect specimen for adding a dramatic focal point to your garden, the weeping blue atlas cedar may look like a tree that’s a challenge to grow, but that isn’t the case. Let me introduce you to this lovely plant and share all the know-how you need to grow it successfully.
What is a weeping blue atlas cedar?
First, I’d like to tell you about the “parent” tree of this beautiful weeping variety. Known simply as the atlas cedar (Cedrus atlantica), it is upright and pyramidal in its growth habit. The ancient Egyptians used oils from this tree in the embalming process and for incense and cosmetics. While we don’t use this tree for such purposes nowadays, it is still an interesting addition to the landscape.
The variety known the blue atlas cedar is Cedrus atlantica var. glauca. It is also upright in form and pyramid shaped. Both of these specimens are lovely trees worth growing, but they reach a whopping 60 to 100 feet tall. The tree I’m focusing on in this article is Cedrus atlantica ‘Glauca Pendula’, the weeping blue atlas cedar, a cultivated variety of the “parent” selection that has a weeping growth habit instead of an upright one.
Mature size of weeping blue atlas trees
Unlike the giant stature of the parent forms, the weeping blue atlas cedar tops out at just 10 to 15 feet in height with a spread between 15 and 20 feet. It’s shaped more like a droopy blob than a pyramid. It’s a slow grower that takes years to reach its mature size, but boy is it worth the wait!
The needles are a beautiful dusty blue. They are only about an inch long and are produced in dense clusters along the branches of the tree. The contorted growth habit of the weeping blue atlas tree means that each tree is unique, so when choosing one at the nursery, take some time to look at the structure of the plant and pick one that appeals to you. Sometimes they have a curvy serpentine shape while other times they have less structure and are more wild-looking.
Both the upright species and its weeping form are monoecious conifers, meaning each plant produces separate male and female cones. The male cones produce pollen in the fall which fertilizes the female cones. The female cones take two years to mature and disperse seed. The plain species of this tree frequently produces female cones, but on the weeping form, the cones are rarely seen except for on extremely mature specimens.
Weeping blue atlas cedar hardiness
A native of the Atlas Mountains that run across the top of the African continent, the weeping blue atlas cedar has good cold tolerance, but should not be considered extremely cold tolerant. In terms of USDA hardiness zones, it will thrive in zones 6-9. The coldest winter temperature this tree will withstand for long lengths of time is -10° F. It may survive shorter cold snaps of temperatures as low as -15°F, but don’t bank on it. It does quite well in Maritime climates such as the Pacific Northwest and the East Coast of the United States, where the ocean water holds additional heat to keep the winter climate more mild.
Where to plant this tree
In the bible of all tree books, Dirr’s Encyclopedia of Hardy Trees and Shrubs, author Michael Dirr says this plant should be used as a specimen tree “where there is ample room for it to spread its feathery, blue boughs.” He then declares that “anything less is a sin.” I couldn’t agree more. Do not put baby in a corner, so to speak. Give this beauty tons of space to spread her wings and she will reward you with an elegant growth habit that is striking beyond compare.
This is not a tree to plant close to your house or along a walkway. It will outgrow the space. You may occasionally find this tree trained as a 2-dimensional espalier tree to be placed flat against a wall or fence. While this is a unique way to use this plant, in my opinion, it doesn’t do it justice. Plus, you’ll need to be pruning it constantly to keep it 2-dimensional (a practice that really limits this plant’s potential).
For the best results, select a site that receives full sun (partial sun is okay, too). Well-drained soil is best, but average garden soil will do just fine. Do not plant a weeping blue atlas cedar in a waterlogged or poorly drained area. Good drainage is essential.
When to plant this tree
Like most other trees, the best times for planting a weeping blue atlas cedar are in the spring or in the autumn. While you may find it easier to find a blue atlas cedar in the spring at a local nursery or from an online source, they are worth seeking out in the fall as well.
Personally, I much prefer planting trees in the autumn when the air temperatures are cool but the soil is still warm. These conditions are ideal for generating new root growth. Plus, you don’t have to water your newly planted tree quite as often when planting in the fall since rainfall is normally more consistent that time of year. Fall planting also allows the tree to have two cool seasons (fall and winter) before the new growth of spring occurs. This gives the tree’s roots time to establish before the tree has to push out new growth.
Training a weeping blue atlas cedar
Often, weeping blue atlas cedar plants are trained and staked into an upright growth habit when they are very young. Because this variety is naturally pendulous, it doesn’t always have a main trunk (known as a central leader). Some nurseries force a leader to develop by staking the plant upright and training it into a certain form. This also allows the nursery to keep the plants tightly spaced in the sales yard, and it keeps the pots from toppling over under the weight of a potentially top-heavy, lopsided tree. But, once the plant is old enough to be sold and moved into your garden, this no longer matters as much.
While you don’t have to, I recommend removing any stakes when the tree is planted and allowing it to grow into its natural, arching form. Yes, the growth habit of a weeping blue atlas cedar is free form to say the least, but it’s a dramatic and stunning free form, so let it be.
How to prune a weeping blue atlas cedar
When it comes to pruning a weeping blue atlas cedar, there is only one ideal time and that is never. It’s very difficult to prune this tree and not mess up its lovely form in some way or another. You can certainly prune out any broken branches or dead growth, but do not try to “limb up” this tree (meaning prune it so none of the branches touch the ground). Just leave it be.
The only situation where pruning may be necessary is if you planted it too close to a walkway and it’s now encroaching on it (see why I warned you to give it plenty of room?). If you must remove a few branches to clear a walkway, do so in the winter or the very early spring, when the plant is not in a period of active growth. Or, if it’s not too large, you can transplant it to a new location where it has more room to grow.
Caring for a weeping blue atlas cedar
Thankfully, weeping blue atlas cedar trees are very low maintenance. The most essential task is to keep the plant well-watered through its first year of growth. Here are some tips to ensure you keep your newly planted weeping blue atlas cedar properly watered through its first year.
- In the summer, every five to seven days set the hose on a trickle, place it at the base of the trunk, and let it run for an hour or two. This is the best way to deeply and thoroughly water a newly planted tree in hot weather.
- In the fall and spring, when natural rainfall occurs more regularly and temperatures are cooler, you can reduce the frequency of watering to once every ten to twelve days. You can use the hose trickle method or apply five gallons of water for every inch of trunk diameter using a watering can or bucket.
- In the winter, if no rain occurs and the ground is not frozen, water by adding five gallons of water for every inch of trunk diameter every 14-21 days. If the ground is frozen solid, there is no need to water.
- For the subsequent two years after that, water only when there hasn’t been enough rainfall for 3 or 4 weeks straight. After those two years pass, no watering is necessary. The roots of this tree run deep once the plant is established.
Fertilizing is not a necessary practice for this tree, but to give it a boost of nutrition after it is established you can use a few cups of an organic granular fertilizer formulated for evergreens, such as Holly-Tone or Jobe’s Evergreen.
Weeping blue atlas cedar is a truly low-maintenance tree with very few pest and disease issues. Bagworms can occasionally prove troublesome (here’s how to manage them), and scale is rare but not unheard of. Root rot can be problematic if the tree is planted in a poorly drained site.
As you can see, the weeping blue atlas cedar is a stunning showpiece that is worthy of a home in your garden. Give it plenty of room and watch it shine.
For more articles on great trees for the landscape, please use the following links:
- Weeping Alaskan cedar
- Narrow trees for small gardens
- White-flowering trees
- 21 Flowering trees for the yard
- 14 More weeping trees