How can I tell if my aspen is dead?
Last year in November we moved into this new house with 8 aspen trees in the front yard. 2 were dead and cut down and left with these 6. Now at the beginning of October our landlord believes the tree is dead and we must have it cut down. She is thinking we didn’t water enough and that’s why the tree died on us. We’re not experts and we’re new to Colorado so we’re not sure if her assessment is right. How can we tell if the tree is dead and how can we determine what cause the death. Can poor deep-root watering be the cause of death over the spring and summer months? The tree seems like the other trees except with a lot less leaves and all dried. We would like to know if they’re dried because of fall or because it’s dead.
Arapahoe County Colorado
1. Aspen trees are not recommended for the home landscape. Aspens thrive above 8,000 feet with rocky soils but are short-lived (less than 20 years) in our metro landscapes. Because they are not growing in their preferred conditions, they tend to become inflicted with host of insect and disease problems such as Poplar borers, Twiggall fly, fungus, cytospora canker, blights, rust, iron chlorosis and oyster shell scale just to name a few. See this link for more information: http://planttalk.colostate.edu/topics/trees-shrubs-vines/1701-aspen-trees/
2. Based on the photo and the history that 2 already died, these trees may not yet be dead (yet) but have been in decline for a while and are probably close to the end of life. The best decision would be to have them removed as you can't reverse the decline of an Aspen tree. There are far better trees to select from for home landscapes that are less problematic and longer-lived.
2a. Be aware that when the tree is removed, there will likely be aspen suckers in nearby planting beds and lawns. This is how aspens regenerate themselves in their natural habitat is by the extensive root system sending out suckers. Prune the suckers to the ground in planting beds or and keep them mowed off in the lawn.
2b. Consult your municipality code; many municipalities have a list of prohibited trees that now include aspen (Populus tremuloides) because they are short-lived and problematic in the landscape.
2c. Here is a great article that might be helpful when you choose to replace the aspen:
3. The 'quick freeze' that occurred October 11 literally freeze-dried tree leaves. With dry air and high winds the past week, the leaves are detaching rather than the normal process of turning color and then falling, so many homeowners think their trees are dead. This isn't necessarily the case, but crispy, dry leaves would lead one to think that. You can scratch a piece of bark off a small branch with a knife or thumbnail. If it is green, the tissue is live. If it is brown, the tissue is dead. But understand that just because there is 'live tissue' doesn't mean the tree is 'healthy'.
4. Poor watering practices can lead to the decline of any tree but is likely not the issue here. In the photo, the trees show to be in a watered landscape so they are obviously getting regular moisture. Deep root watering is generally done in the winter months when there is no moisture from irrigation systems and long periods of no snow. See the following CSU Fact Sheet on winter watering:
5. Here is additional information on Colorado gardening for newcomers: