Lady Bird's legacy

This week we went to the Lady Bird Johnson Wildflower Center for a volunteer work day. Senior Botanist Damon Waitt and Joe Marcus, who is the Center's horticulturalist, met us on the grounds to give us a tour of their planned Texas Arboretum. They hope to have over 50 species of Oaks and 170-something species of trees from around the state. It will be a challenge in some cases, since East Texas soil is acidic, while Austin sits on a limestone escarpment, making it highly alkaline. But trees are resilient, and they plan to give it their best shot.

They have over 400 volunteers at the Center, so they can get ground work done easily. We spent the day climbing four large Escarpment Live Oaks (Q. fusiformis) to prune out dead wood and separate the canopies. The vision they have developed (with a landscape architect) for the arboretum is to clear out most of the understory plants to reveal a wide-open savannah dotted with room-like trees and groups of trees. They have made a small start to that end, as these four trees were the target of a local Boy Scout's Eagle project. So far, they have opened up a lot of the interior of the "room" and mulched it with Ashe Juniper (Juniperus asheii) harvested and ground on site. Their next step was going to be to continue clearing low plants, building picnic tables, etc. I'm sure they will be quite pleased to see the huge mess we left that they will have to move before they can continue working (nothing beats a "cut-and-drop" job for us climbers). Once it is finished, Damon hopes to use this site as an example of their vision when they show potential donors the arboretum.

When it is finished (maybe in two years or so), the arboretum will include a trail about 3/4-mile long and a spur to connect with the nearby restoration research trails. We're hoping to work on more pruning projects before then. There are few jobs as satisfying as pruning Live Oaks that have never been climbed--the before/after contrast is quite striking. All we have to do in most cases is cut the dead wood and the natural beauty of the trees bursts forth.

You can see in these pictures (courtesy of WFC photgrapher Bruce Leander) that I had my helmet liner on. It wasn't as cold as some recent days here, but we timed it so the weather was unfavorable for the fungus that causes Oak Wilt, Ceratocystis fagacaerum, and the nitidulid beetles that sometimes carry it from tree to tree. There are active Oak Wilt centers on two sides of the WFC property, including several trees in the nearby Veloway. It's more common for the disease to spread in Live Oaks through underground root grafts, but we still waited for cool weather, disinfected our tools, and painted pruning cuts whenever we had to break through living tissue. The years-dead, dried-out cuts were left in their natural state.

The Center is wrestling with the decision of whether to trench the edges of the property to help prevent root transmission of the disease. The City streets and the underlying utilities probably helped with that goal, but trees have a knack for breaching these defenses. So, a trench that goes in too early will potentially be a wasted effort. Obviously, a trench too late could be devastating. Since trenching is expensive, there's a strong motivation to wait as long as possible. The WFC has 379 acres, so we're talking about a lot of trench. I hope they never get infected, but I'm sure if they do they will take the opportunity to educate visitors on how best to manage and prevent the disease.

I didn't mean to go off on such a downer. I am happy to report that the trees we saw were marvels of nature and none showed any sign of serious disease issues. The Wildflower Center is a great place to visit or spend a day working. Local homeowners and gardeners can benefit especially because the range of plants is amazing. Everyone should try to go in Spring for the big wildflower show, but any time you go you will see something surprising and beautiful that you might decide to put in your own garden. Most plants have ID tags to help you get the right stuff. If you check the WFC Web site (linked above), you can go to the semi-annual plant sale and buy seeds or plants propagated at the Center. Get yourself out there! You won't regret it.