En EspaŅol
Share

Ask Mr. Smarty Plants

Mr. Smarty Plants - Replacing mature Arizona Ash trees in Austin

Ask Mr. Smarty Plants is a free service provided by the staff and volunteers at the Lady Bird Johnson Wildflower Center.

Search Smarty Plants
    
 
See a list of all Smarty Plants questions
Can't find the answer in our existing FAQs, submit a question to Mr. Smarty Plants.

Need help with plant identification, visit the plant identification page.
 
rate this answer
Not Yet Rated

Friday - August 26, 2011

From: Austin, TX
Region: Southwest
Topic: Compost and Mulch, Planting, Transplants, Shade Tolerant, Trees
Title: Replacing mature Arizona Ash trees in Austin
Answered by: Barbara Medford

QUESTION:

Mr. Smarty Plants, I have 2 very large, very old Arizona Ash trees in my yard. I want to remove them and replace them with something like Cedar Elm or Chinquapin Oak. The problem is that they are the only thing providing my house and yard with shade, so I'm hesitant to remove them until I absolutely have to. Can I go ahead and plant the new trees this fall so that they can get some height before I have to remove the others? If yes, how close can I plant them to the old trees? (The old trees are really in the perfect spots in our small yard, so I want the new ones as close as possible.)

ANSWER:

We have thought about this for several days and can come up with no good solution. The roots of your mature trees should be extending out two to three times the distance to the edge of the shadeline from the trunk. You say your yard is small and the existing trees are in the perfect spot, which is to say, the only spot for a large shade tree. We are also assuming that if you have any ornamental plants in that area, they need shade. We have seen examples of areas where a large tree was unexpectedly cut down or blown down by a storm, and all the shade plants beneath it suffered. If you try to dig holes to put in new trees near the old trees, you will damage the roots of the old trees, maybe even to the point of killing them. And you will be asking the delicate roots of the new tree to suddenly compete with the more established, and thirstier, old roots. That's kind of a lose-lose solution; you could end up with no trees at all.

According to this USDA Plant ProfileFraxinus velutina (Arizona ash) does not even grow natively to Travis County. As its name implies, it is more a desert plant, but with our current weather conditions your trees are likely feeling right at home. The Arizona Ash is often victim to borers and verticillium wilt, resulting in being somewhat short-lived.

However, if the trees do not seem to be in imminent danger of dying, we would suggest you hold onto them as long as feasible. In the meantime, if you do, indeed, have shade-loving understory plants, we would recommend transplanting them during the Fall and early Spring to other shady spots, or accepting that you will likely lose them. If you decide to go ahead and take out the old trees, that could be done now or in the Fall but you need to then do extensive preparation for the new trees which should be planted in January, when they are more dormant.

This extensive preparation should include the engaging of professional arborists who can get the trees down without undue damage to your house or other plants. Next, have the ash roots ground out, for at least as far out as your arborist estimates the hole for the new trees will need to be. While you will probably want to have any large root pieces removed, the ground remnants will serve as a good compost in the soil, and help improve drainage, always an essential in our alkaline clay soil. We again advise that you take the advice of the arborist on preparation of the soil and size of the hole.

Now, about the new trees, whenever you plant them. Again, plant in the Winter, and do not buy the trees until you are ready to plant. There are always sales on trees in late Summer or early Fall, but they have likely already been out of the ground and in a pot for months, and will have to wait there more months for the appropriate planting time. This often results in roots growing round and round in the pot, which can strangle the tree. We looked at our webpage on both the trees you mentioned as replacements; follow the links to read more information on each tree.

Ulmus crassifolia (Cedar elm) - nicely proportioned, drought tolerant

Quercus muehlenbergii (Chinkapin oak) - relatively fast growing and free of diseases and pests

 

From the Image Gallery


Chinkapin oak
Quercus muehlenbergii

Cedar elm
Ulmus crassifolia

More Planting Questions

Growing butterfly weed as a girl scout project
July 30, 2012 - We have a group of girl scouts who want to sell 'crafts' at a farmers market. I am wanting to steer the moms and girls in a different direction. I was wondering if you think that butterfly weed woul...
view the full question and answer

Too late to begin planting in May in Austin?
April 30, 2008 - Is it too late to begin planting in May? I live in Austin Texas and have finally completed my plans for a native Texas landscaping (plants and grass) of my front yard. I'd like to get the landscapi...
view the full question and answer

How close can house be built to live oak from Austin
May 30, 2012 - We have a healthy 21" live oak tree on our lot and are planning to build a home in Circle C subdivision in southwest austin. The home foundation will be within 15' of the large live oak. Need your h...
view the full question and answer

Problems with evergreen sumac in San Antonio
May 03, 2012 - I planted 5 5-gallon (approximately 2 feet tall) evergreen sumac in early January. Since that time they have sprouted out new shoot with new leaves several times - every time the leaves have wilted a...
view the full question and answer

Removing leaves before transplanting from Miami
August 27, 2009 - What is good idea to remove some leaves before transplanting a plant??
view the full question and answer

Smarty Plants's Facebook profile Support the Wildflower Center by Donating Online or Becoming a Member today.

Mr. Smarty Plants wants you to be his Facebook friend. Click the Facebook icon to add yourself to Mr. Smarty Plants list of friends.
E-NEWSLETTER | BECOME A MEMBER | DONATE NOW | MEDIA | SITEMAP
© 2014 Lady Bird Johnson Wildflower Center