Populus tremula 'erecta'
This is one of my first batch of aspen. You can see how the new leaves come in red. This one is 4-5 feet tall.
Swedish aspen is the tree for fast growth in small spaces.
- 3 to 5 feet per year.
- Only gets about 3 feet wide.
- Very little suckering compared to other poplar.
- No fluff.
- Good on heavy clay soils.
- Plant by front sidewalk and driveway as partial screen. (Recommend 6' foot spacing)
- Acreages: Set back from driveway on 15 foot spacing for a formal 'Avenue of columns' entrance.
- Quick privacy screen. (Best practice: Alternate with a tall shrub. Swedish aspen lose their lower branches as they get older when grown close enough to touch.)
- Windbreak: Use as one row when space is restricted. Provides shelter to establish better, long term windbreak trees such as white spruce.
Pricing: All our Swedish aspen are $8-$10/foot. Sizes range from 3 to 9 feet. Delivery is available. Click on the phone or email icon below our logo to contact us for this tree.
News Flash! Swedish aspen are only sold between August 15 and September 15.
This is due to Bronze Leaf Disease. Read about BLD at the bottom of the page.
Now, back to your interrupted web page...
Swedish Aspen is a cultivar of European trembling aspen with a much more acute node angle. The branches ascend almost parallel to the trunk. This makes for a tree that is shaped like a candle flame. Very striking.
A fine example of a mature Swedish Aspen starting to turn colour in the fall. In an open sunny location like this, Swedish Aspen will hold on to their lower branches.
Because of it's size, it is ideal for use on small yards, and can be used fairly close to the house. It's tall upright habit make it formal looking. Because it's a poplar it grows fast. It is a good tree to plant while you wait for your other trees to get big.
The poplars are dioceious -- male and female flowers are on separate plants. All Swedish Aspens are male. Some pollen in the spring. No fluff later.
Swedish Aspen is FAST. With good growing conditions, (keep damp, fertilize lightly in October and June) it will grow 5 feet a year, once established. Even the first year in it's new home they often put on a two feet or more.
Like all poplar, it needs lots of sun. -- at least 6 hours a day of full sun. Do some careful checking before planting in the narrow canyons between large houses on small lots in some modern developments. White or light coloured siding on the north side of these suburban canyons can help.
Also like all poplar it sheds it's lower branches when they are shaded. Basically, the tree is abandoning unproductive food factories, and concentrating it's resources on the more productive leaves near the top.
The leaves when first open can range from dark red to rusty orange. Notice how thin and fragile the leaf looks. It will fill in a few days.
With exposure to warm temperatures and sunlight, the chlorophyll factories start up, turning the leaf green.
Some garden centres will claim that Swedish Aspen does not sucker. Not true. While it is less prone to suckering than many of the poplar family, it will sucker when its roots are damaged. If you plant a flower bed that gets regular shovel work near an aspen, you will get suckers in the flower bed. You will also get occasional suckers in the lawn, but these are dealt with by the mower.
Warning: Poplar roots are invasive. They will find their way through small cracks in pipes. This can be a problem with older sewer lines (non-plastic) as the joints on these frequently leak. It can also be a problem if you have weeping tile near the surface. Weeping tile at the foot of a basement foundation is not usually at risk from poplar. Their roots are mostly right at the surface. For obvious reasons they should not be planted on or near septic fields. This is not a problem with poured concrete foundations. It is not a problem with water lines, or ABS (black plastic) sewer lines.
Swedish Aspen leaves aren't green when they open. Rather they are rusty orange to red. The leaves open without any chlorophyll, but with some of the carotenoids (xanthophyll -- yellow & lycopene -- red) and anthocyanins (red, purple pigments) in place. In cool weather they will maintain this colour for one to two weeks. In warm weather it lasts only a few days. This same red pigment on some years gives the fall foliage a pink colour.
I do NOT recommend Swedish aspen as a screening tree.
As mentioned above, the lower branches are shed when shaded. Planted close together, the lower branches are more quickly shaded. 10 years after you plant them, the trees are 25 -35 feet tall with branches only on the top half of the tree. The effect is about as private as a barb wire fence.
The elegance of this tree is its narrow shape. In a screening row, you lose this, and just get a green wall. Plant a row of [Skybound Cedar] (/Trees/Conifers/Cedars/Skybound_Cedar.html) if you want a green wall. They are good at walls.
Close spacing creates a microclimate in the branches of high humidity. More damage results from branches hitting each other in the wind. Both circumstances increase the likelihood of fungal disease such as BLD. (See below.)
I lose sales because of this advice. At best I sell half the trees I could. So be it. It's important to me that you get the right tree, and use it in a way that is beautiful. In the long run, I figure that giving the best advice I can will pay off.
My opinion for better ways to use Swedish Aspen:
For the small lot owner:
Put up a fence. This gives you immediate screening. Plant one aspen at the midpoint of each fence section. In 5 years you now have a set of stately green columns, with much of the effect of an ancient Greek temple.
Variation. Add a vine -- clematis, or virginia creeper to cover the fence. This has the advantage that you can use cheap fence -- 2x4's and chicken wire will work.
Variation. Plant sunflowers every foot between the aspen. They will give you a privacy screen by mid summer, and the chickadees will thank you if you leave them up in the fall.
Plant a pattern with aspen alternating with one or two shrubs. Pick shrubs that are tall enough to provide the screening you want. The aspen will still provide the Greek temple effect, and the shrubs will provide the screening. Willows, dogwoods, ninebark, cotoneaster, high bush cranberry, & native chokecherry are all options.
Use them as curb trees for the front of your house, or along the driveway.
For the acreage owner:
15 feet back from the driveway, plant an aspen every 12 feet on both sides. Another 15 further back plant a pine lining up with the spaces. The aspen in a very few years will provide a colonnade on either side of the driveway. The pines will later take over this role, being majestic when the aspen are nearing their end of life.
Plant as one row of a screen along the road allowance. Alternate Swedish Aspen and two red osier dogwoods half way up the ditch bank (check your county's road edge bylaws Some like larger margins) Being halfway up, they will have access to the extra water that accumulates in the ditch. Poplar is moderately salt tolerant, but if your ditch is immediately next to a heavily salted hill or intersection, try one or two trees the first year. Back this up with a row of golden willow alternating with spruce.
Plant 6 or 12 in a circle 75 feet across. This will give the 'Stonehenge' look. A mystic circle. Plant a single oak tree at the center to extend this effect.
In any case, I suggest leaving room for your mower between the trees and the property edge. This makes keeping it neat looking quite easy.
Aspen are normally water pigs. It's hard to overwater, and they prefer soils that are constantly moist. Loam is best. They tolerate fairly heavy clay soils, but do not do well in a water logged clay soil. If planted in sandy soil they will need supplemental irrigation their entire life.
There are a bunch of native plants that do well in the partial shade. Lungwort, false soloman's seal, Canada bunchberry all come to mind. My woods are currently full of wild rose and wild raspberry.
Aspen are not long lived trees. Plan on replacing them in 30 years.
Swedish Aspen and Bronze Leaf Disease
Swedish Aspen is susceptible to a fungus called Bronze Leaf Disease. Individual leaves, and clusters of leaves turn rusty red or copper coloured in late summer. The veins remain green. The leave doesn't get 'crispy' the way you would expect a dead leaf to, but is sort of leathery. The fungus will spread inward down the stem, eventually killing the tree.
Closeup of infected leaves
Here's a look at a typical infected tree. You can see that finding and removing all of the affected leaves is a time consuming operation.
The fungus overwinters in the leaves either on the tree or on the ground. In spring, the fungus releases spores which infect newly opened leaves. The leaves are without symptoms until August.
All swedish aspens are clones from a single specimen. There is no chance to breed a resistant type. There is no treatment for BLD at this time.
One producer in Manitoba has stopped growing Swedish Aspen. Control measures were taking too much time. Manitoba summers tend to be hot and humid, much more humid than Alberta generally, so it may be possible to control here.
You can fight a delaying action:
Remove any infected leaves immediately. If more than a quarter of the leaves on a twig are infected remove the twig 6" below the bottom infected leaf. Burn or dispose of with your garden waste. The spores remain viable through most household compost processes. (Not hot enough)
In fall do a careful job of leaf removal. Do not mulch aspen leaves into the lawn with your mower.
After leaf drop carefully examine your aspen trees for clinging leaves. You may be able to knock them down with a directed hose spray. If the tree is sturdy enough, lean a ladder against it, and remove by hand.
If you have a badly infected tree, or you can't reach the affected part, cut it down. You may be able to train up one of the inevitable suckers to replace it.
You can try bordeaux's mixture as a treatment. Don't know that it works, but don't know that it doesn't. It is effective against other fungi on grape vines, and it's cheap, and not particularly hazardous. Spray weekly starting as the buds start to open. Then on any infected leaves later. Report back to me on your results.
Here are some steps you can use to keep out of trouble:
Buy aspen only in late summer. This guarantees that you are getting clean stock. I have seen infected trees at major box stores. I have bought infected trees from major suppliers. For this reason I won't sell you my aspens until the 15th of August. You can come and pick them out before then, but they don't leave here unless they are green.
Do NOT plant the Great Green Wall. The close environment makes for higher humidity and the minor injuries the leaves and twigs get from hitting each other in the wind make it easier for the infection to spread.
If your neighbours are growing swedish aspen, then you shouldn't. One of the reasons this disease spreads so well is that the tree is overused.
One answer is to plant something else. The closest tree is a North American trembling aspen cultivar called Prairie Skyrise. It and a raft of other options are detailed here: Skinny Trees
Another answer is to build a trellis, and grow vines. I don't do vines yet.
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