Scarlet Buckeye (Aesculus splendens)

The arboretum's only scarlet buckeye (Aesculus splendens) appears to be in its death throws. Leaves are absent and its limbs show evidence of decay, with patches of peeling bark. This tree was previously covered in a blogpost from 2021, and even earlier in a blogpost from 2018, alongside its old friend the peppervine (Ampelopsis arborea). Careful examination reveals some signs of life, but the outlook is grim.

This placard has weathered more than a few seasons. Our scarlet buckeye is, at minimum, 37 years old. It was purchased in 1988, from Woodlanders Nursery (Aiken, South Carolina).

 

You can find this tree on your right as you walk from the Fitness Center towards the Hargrove Bandshell.

 

We can see all the branches―they aren't concealed by leaves.

And up close the branches do not look good. Peeling bark opens the tree to attacks by insects and fungi, and it indicates internal deficiencies within the tree's health that make these problems more deadly.

 

A will to live is still present. Unfortunately, this tiny leaf is at the tip of a branch that already shows significant decay.

The trunk does not have any peeling bark.

And looking closely at the trunk, two green buds were found. This is one. Do you see it?

Zooming in on the trunk, we see new green growth.

 

This is the second green bud found on the trunk. Perhaps more will appear soon.

 

Although the prognosis is not good, the arboretum isn't a place to rush and cut a tree down―we're not in a hurry to determine the next step. Let's give the specimen a reprieve, and see what happens in the coming weeks.

Big-Leaf Magnolia (Magnolia macrophylla)

Last month, the big-leaf magnolia caught our eye with its large, drooping, creamy white flowers. On par with the American lotus (Nelumbo lutea) for the prize of "biggest flower native to North America," this rare specimen deserves more attention. We currently have three plantings of big-leaf magnolia in the collection, and all three would benefit from some spring-cleaning activities, like pruning and weeding. 

 

Two big-leaf magnolias are pictured here. There is a larger one in the center, and a smaller one is leaning on the right side of the frame. The smaller one was planted in 2009, while the larger one was planted a few years prior. Both were badly damaged in August 2020, during the storm winds from Hurricane Laura. In this photo, we see the work to be done: surrounding shrubs and vines are encroaching on the space allotted to the big-leaf magnolias.

We cut back wax myrtle (Myrica cerifera) shrubs to allow more sunlight for the magnolias. Virginia creeper (Parthenocissus quinquefolia), poison ivy (Toxicodendron radicans), and some grape (Vitis sp.) were all pulled from around the base of the skinny trunks. A few stalks of lizard tail (Saururus cernuus) were also snipped to increase signage visibility.

Despite being more than 15-years-old, these are still small trees, and they need help when it comes to competing with their more aggressive neighbors. And since this species isn't particularly robust, we are keeping both trees in the catalogue, rather than cutting down the smaller of the two. We don't want to cut the small tree for a couple of reasons: it doesn't take up much space, and it is our back-up plan or insurance policy if the larger tree dies. A falling widow-maker could easily cause such a fatality.

Big-Leaf Magnolia (Magnolia macrophylla)

The big-leaf magnolia (Magnolia macrophylla) is blooming this week.

The trunk and branches are spindly. The leaves and flowers are big! You will need to gently pull the leaves down to get a better look at the beautiful flower.

Flowers petals are long, large and droopy.

The flowers are brilliantly white, but for a short while. It seems like this flower lasted only a single day before yellowing. There are more buds higher up, but a ladder would be necessary for studying the flowers, as the leaves mostly obscure the blooms.

Dewberry Picking in the Arboretum

At the end of April, dewberry (Rubus trivialis) fruits are ripening in northwest Louisiana. Dewberry is a weedy plant―it readily germinates and thrives in unmanicured areas, such as along roadsides or fencelines. It also volunteers in areas where gardeners don't want it. This makes dewberry a classic "nuisance plant" because it spreads rapidly and the vines are covered with prickles. However, this time of year, it can be a joy to find: the wild, black fruits are a lightly-sweet, flavorful snack. 

Dewberry vines volunteer all over the Centenary College campus. Most are unwanted, and they are pulled up or chopped down. In the arboretum, there are more than a few cultivated patches, and there is one really big uncultivated patch. Near the Student Union Building, we have a mini-wilderness area that has developed into one large dewberry patch. 

On Saturday morning, two arboretum guests, a brother and sister duo, sampled and collected dewberries along the edge of the volunteer recruitment zone.

Dewberry wasn't planted in this spot; it volunteered here and has thoroughly entwined itself among the trees and shrubs. 

 

These young people were able to quickly identify the fruits and pick them. Neither individual complained about the prickles—the fruits often appear above the vines, making it easy to collect the fruits without being harmed by the vine's armor. Having small hands with deft fingers and being closer to the ground are advantageous!

 

Not all of the fruits are ripe at the same moment. Fruits in this patch have been ripening for nearly a week.

The dark black fruit is ripe and ready to be picked.

The red fruits are very pretty, but these aren't ripe. Let those develop on the vine another day.

Brother and sister picked three cups of dewberries in about 20 minutes, and then moved on to investigate other areas of the arboretum. That's $45/hr worth of fruit. Not bad!

Mexican Plum (Prunus mexicana)

We've added another Mexican plum (Prunus mexicana) to the arboretum catalogue. This species is a fan favorite, producing delectable and highly-colored fruits that make a complete mess during their season. Squirrels eat them; bugs eat them; we eat them. Raccoons and possums eat them after hours when nobody is looking. The mature trees produce so much fruit that it simply lays about on the ground. This time of year, if you look under any of those trees, you will find seedlings. The individual pictured below is one such seedling.

Last April, this young tree was collected from under the mature Mexican plum growing on the steep slope near Mickle Hall (see here). It survived transplanting and the long hot summer months thanks to an onerous watering regime. Today, it is almost a foot tall.

Since the fresh green leaves developed in full sun, we don't need to worry about shocking it with too much sunlight when we plant it.

We planted it in full sun near the top of a gradual slope on the north side of the Cline Hall dormitory. This is an open, grassy area, and this time of year we allow the wildflowers to grow tall. The stakes with pink tape are necessary for calling attention to our small tree—we don't want it to be stepped on, stomped flat, or mowed over.

Red Buckeye (Aesculus pavia)

On October 25, 2023, first-year students collected and planted seeds from red buckeyes in the arboretum. Approximately a month later, seedlings emerged from the dirt. Now, 16 months later, we see the first flowers! That's fast development.

Professor Rachel Johnson brought two groups of students to the arboretum for tours. The first group was from an 8 a.m. class. Students picked up 5 seeds and planted them in this spot, marked by the metal tag.

At minimum, three of the five seeds germinated. One plant remains, and it is short and wide, and it has one red panicle. 

This is full sun. Online literature says that red buckeyes can grow in full sun or shade, so this is one of our experimental spots for full sun conditions. The majority of our other buckeyes grow in part or full shade.

Students from Professor Johnson's noon class also planted 5 seeds. They were slower to germinate by just a week or two. Several seedlings emerged, and died back, and started again.

Today, we see two little plants. One is significantly larger than the other and it has one red panicle.

The arboretum has a steadily growing collection of red buckeyes. We are really hoping to draw in the ruby-throated hummingbirds with these clusters of pretty red flowers.

You can read more about the germination project on an earlier post, found here.

 

Winged Elm (Ulmus alata)

Today we added a young winged elm (Ulmus alata) to the arboretum collection. This species grows abundantly in Caddo Parish—it is very 'weedy'. There are three mature winged elms in the arboretum: one is an on-site native; one was intentionally collected from Walter B. Jacobs Nature Park in Caddo Parish; and one is a volunteer. Our new recruit was planted in full sun near Mickle Hall, and it is expected to flourish with very little maintenance.

This specimen was collected in Caddo Parish, just north of Shreveport. Discovered in 2023, after it had germinated in a pot of soil meant for another plant, it now enters the Centenary campus as a 2-year-old, measuring 18 inches tall.

Our little tree has already leafed-out. We see serrate leaf margins.

And looking closer, we see a slight ridge along the stem. This young tree is developing its corky 'wings', which help us identify this tree as a 'winged' elm. Sweet gum trees (Liquidambar styraciflua) also have this characteristic.

 

 

US Forest Service Ulmus alata Fact Sheet