Persimmon (Diospyros virginiana)

In October 2023, we identified and collected eight persimmon seeds from the Caney Lake district of Kisatchie National Forest in Webster Parish. The seeds were immediately planted in one big pot, and during the spring of 2024, they germinated. Seven seedlings grew vigorously in the same pot for approximately a year. 

This past spring, five of the saplings were planted in the arboretum, and two were set aside and repotted as a backup plan. Now that it's June, four out of the five saplings planted in the arboretum are alive, and one in particular looks great. The overall high germination rate and low mortality of these specimens shows how vigorously our native trees must fight for survival in wild conditions. Pampered and given every opportunity by helping human hands, they succeed easily.

This persimmon sapling grows in full sun toward the top of the grassy slope east of Rotary Hall. It is a year old. The trunk is very slender and wobbles under the weight of the big green leaves. Possums are eagerly awaiting the maturity of this tree, although it will be quite a few marsupial generations before any of them get a taste. Perhaps there's an old possum proverb: "The best time for an arboretum curator to plant a persimmon tree was ten generations ago."

Tulip Poplar (Liriodendron tulipifera)

Our little tulip poplar (Liriodendron tulipifera) is growing up nicely. In 2022, this individual volunteered on the north edge of the arboretum, down slope from mature tulip poplars. The following year it was extracted and relocated to a more suitable spot. 

 

In April 2023, the sapling was photographed against a black umbrella when it was less than 8 inches tall. Given that this species can grow to become one of the largest trees (over 100 feet) in Eastern North America, we have on record some modest beginnings.

                                     

Today, it looks healthy and appears to be living up to the expectation of being a 'fast-grower'. Pictured here in June 2025, we see that our tree has grown significantly. Based on photos from last December, it may have nearly doubled in height. The trunk exhibits a slight lean due to the  shade cast by a nearby swamp dogwood (Cornus foemina), but our tree has successfully outgrown that competition. Additional staking would be a prudent intervention to correct the current lean while the tree is still supple. In another decade it will be big enough to support numerous bees and moths with its leaves and nectar.

 

To see a post on the gorgeous fall colors offered by this specimen, click here. 

Summer Concerns; Irrigation in the Arboretum

Centenary College, "Where the sleepy, silver bayou, / Gleams among the pines...." The Alma Mater says that the campus once had a bayou. What happened to it? There are still a few big pine trees, but much has changed over the past hundred years. 

The growth of modern cities with their necessary infrastructure of concrete streets & sewerage has greatly altered local hydrology. Whereas in the past rains might saturate a richly developed soil, rainwater is now swiftly funneled across impermeable barriers of roof-and-road into storm sewers and drainage canals. For our purposes here this means that despite getting on average 50+ inches of rain per year, summer conditions can easily cause drought. Since we need to keep our wide array of arboretum species alive for academic purposes and keep the non-native grass alive for aesthetics, this means we need to supplement our natural precipitation with artificial irrigation, mostly in the form of sprinklers.

An in-ground network of pipes supplies well water to most of the arboretum, and much of that system can be programmed to run automatically. Some lines of irrigation must be manually turned on, and water hoses must be hauled and stretched to reach a few small patches.

The sprinkler system is an absolute necessity for maintaining the health of the arboretum. The fact that it can provide an amusing diversion is a nice side-benefit.

Laurel Cherry (Prunus caroliniana)

Last week on the blog we explained that, even though a tree looks pitiful and nearly dead, we shouldn't rush to cut it down and replace it. This week, we need to explain why a tree that looks beautifully green and productive needs to be cut down and replaced as soon as possible.  

 

A laurel cherry (Prunus caroliniana) is pictured center, completely blending in with its neighbors. On the right side of the frame, we see a non-decaying trunk of a deceased eastern red cedar (Juniperus virginiana) [read more about that individual here].

 

After removing the lower branches, we can now see the trunk of the laurel cherry. It is definitely leaning. 

It's leaning to the south. 

The southward leaning branches were heavy with leaves, and the fruits are numerous. 

Laurel cherry trees are handsome evergreen trees and the fruits ripen to blue. Keep in mind that this species is poisonous.

 

This is an interesting tree, and other than the lean, it appears to be healthy, so why cut it down? There are three reasons. First, the base of the trunk shows damage, which is a serious health concern. Second, there are several laurel cherry trees in the arboretum collection, and there are undocumented volunteers as well, so even if we cut this one tree down, the species will still have a strong presence in the arboretum. Finally, we have a young laurel cherry growing near the base of the trunk, so we can cut the big tree down and allow the young laurel cherry a chance to thrive. For these reasons, this richly green laurel cherry is on the docket for removal. 

 

In this photo, we see that the lower trunk of the laurel cherry is damaged. Also, on the left side of the frame, we can see the young laurel cherry ready to take its place. The young tree has grown up in 100% shade, so if we cut down the older tree all at once, it might be too much of a shock for the little one. So, for today, we started on the gradual process by removing all of the lower branches of the big tree. And in the following months we will steadily remove more branches, slowly exposing the smaller tree to more direct sunlight.

 

 

See previous posts on laurel cherry trees in 2023, and from early 2020 and late 2020.

 

Lady Bird Johnson page on Laurel Cherry 

USDA page on Laurel Cherry 

Black Willow (Salix nigra) Update

Perhaps when you see a tree, you think: "Look at this messy pile of lumber and twigs. I don't have anything in common with this thing." Always remember, however, that you and the tree share one thing: a will to live. This will is more apparent in fast growing trees that thrive in harsh, or seemingly impossible, conditions. 

 

 

 

The following photos show us a black willow (Salix nigra) that has an ignominious history. Like a fairybook creature from some nursery rhyme, it grew up in a discarded boot. You can read about that in a previous post. The last time we checked in on this specimen, nearly a year ago, it was about nine feet tall.

Given the height of these two boys, I'd say this tree has grown to around twelve feet tall. Three extra feet is not bad for less than a year of new growth.

 

Individuals from all walks of life (indeed, some vertical walks...) can enjoy a black willow. Here is a green anole (Anolis carolinensis) doing just that.

Black willows can grow to be fifty feet tall or end up as a very large complex of shrub-like growth. If it keeps growing at this rate, we'll need to prune this fellow one day soon.

New Recruit: Elm (Ulmus sp.)

 

A spice bush (Lindera benzoin) and an elm (Ulmus sp.) have volunteered next to one another in a bed of fringe trees (Chionanthus virginicus) located near the campus Fitness Center. Our previous post was devoted to the spice bush. In this post, we take a look at the young elm.

At less than two years old, this elm is already three feet tall. It's growing at the bottom of a gradual slope, next to a concrete drainage channel. Right now, this is a full sun location.

As seen in the above photo, the young elm does not have a single leader; it is attempting to develop a divided trunk. Ought we allow this, or should we intervene to encourage a single stem?

The tree seems committed to having two trunks: the two stems appear to be of the same thickness and length.

These are simple leaves alternating along the stem. Since we do not see 'wings' along the stems, we will refrain from identifying this as a winged elm (Ulmus alata).

This leaf is 3 inches long, with a miniscule petiole. It has an ovate shape that tapers to a sharp point. The upper surface is rough, gritty like sandpaper, which is characterisitic of slippery elm (Ulmus rubra).

Underneath, leaves are light green.

Leaf margins are doubly serrated, which is typical of elm leaves. However, the base is interestingly symmetrical, which tells us that this isn't a slippery elm (Ulmus rubra).

The arboretum is home to one slippery elm and three winged elms, as well as a cedar elm (Ulmus crassifolia). Elms are known to hybridize, so perhaps we have a hybrid. Close examination of the other elms will be helpful in understanding more about the new recruit.

New Recruit: Spice Bush (Lindera benzoin)

 

On the southern edge of the arboretum, we have two new recuits: a spice bush (Lindera benzoin) and an elm (Ulmus sp.). Last year the young plants volunteered in a bed of fringe trees (Chionanthus virginicus). After thriving for many years, the grouping of fringe trees took a turn for the worse during 2019: we had to completely remove one tree this year, and the two remaining individuals are not particularly excellent examples of the species. With that being said, we need something new in this location, and luckily, we have two vigorous volunteers to fill out the established bed.  This post is devoted to the spice bush.

 

Pictured center, next to the ruler, we see a spice bush (Lindera benzoin). It stands at 3 feet, 5 inches. It volunteered sometime before the summer of 2022, and its rapid growth was observed over the following months.

 

This is a spice 'bush,' although it looks to be more like a young tree, with one major stem supporting large leaves and a few delicate branches.

 

 

This spice bush is developing quickly; it didn't waste any time this spring putting out fresh, green growth.

 

 

The floppy, fragrant leaves alternate along the stem.

 

The leaf shape is obovate with a pointed tip and wavy margins. This leaf measures 5½ inches long, and the petiole is an additional ¾ inch. The upper surface is smooth.

 

Underneath, it's a little fuzzy. Crumpling these leaves produces a pleasant aroma, something like lemon and certainly spicy.

 

 

 

 

Tree of the Week: Eastern Hop Hornbeam (Ostrya virginiana)

 

Our tree of the week is an eastern hop hornbeam (Ostrya virginiana), growing mid-slope between Hamilton Hall and the Student Union Building. This tree is at least 10 years old. It is a volunteer that first entered the arboretum catalogue as a 'seedling' in 2012.

 

This eastern hop hornbeam grows in the shade of a very large, on-site native Shumard oak (Quercus shumardii).

 

Two additional eastern hop hornbeams grow directly across the sidewalk. By contrast, they are currently growing in full sun conditions. In total, we have three eastern hop hornbeams in this one area. All are volunteers and all currently have fruits. These trees are most likely all descendants of a specimen collected from Cypress Lake in Bossier Parish. That tree was collected and planted in 1989, and died in 2013.

The "hops" drew our attention this week. This is a fruit cluster of the eastern hop hornbeam.

 

We snipped a branchlet for a photoshoot. Here we see two fruit clusters and the pale undersides of the leaves.

 

Some fruit clusters are long; some are short. This one is on the longer side, measuring more than 2 inches in length.

 

Be careful handling these fruit clusters. There are nearly invisible hairs covering the 'hops' that may irritate your skin. For pictures of ripe fruits, see an older blog post, found here.

 

Hop hornbeam leaves are simple, dark green on the upper surface, egg-shaped, and soft to the touch. This leaf measures 4 inches in length.

 

Underneath, leaves are pale green. In this photo, we can see the finely serrated margins.

 

 

 

Tree of the Week: Post Oak (Quercus stellata)

 

Over the past year we have paid special attention to the post oaks of northwest Louisiana. It all started with the passing of an on-site-native post oak, followed by a resolution to increase the number of post oaks on campus. This requires ripe acorns. When the search for those failed, a modest effort was made with the transplanting of a young post oak.  Now that spring pollination is complete, the search for acorns has begun anew. Today we spotted post oak acorns in the arboretum!

We have a post oak that is a little more than 22 years old. It grows at the western edge of the arboretum, near Rotary Hall. This tree isn't big, but it has already started to produce acorns. You can see more pictures of this specimen here.

Acorns can easily be examined on the lower limbs of the tree. No ladder is needed.

 

Two immature post oak acorns, photographed June 19, 2022

 

Developing post oak acorn, photographed June 19, 2022

Update: How will our acorns fare under the early summer drought? Time will tell.

Tree of the Week: Parsley Hawthorn (Crataegus marshallii)

Currently, there is only one parsley hawthorn (Crataegus marshallii) in the arboretum collection. It grows on a steep slope, in full sun, near the southwest corner of Mickle Hall. Overall, this parsley hawthorn is a very fine specimen whose growth has been unhindered. This has allowed the tree to develop a nice form and it positively exudes an aura of health.

Unfortunately, despite this vigor, our parsley hawthorn is battling a fungal infection. Over the past several weeks, the rounded canopy has exhibited a pink hue, not from any ripening fruit, but from a pervasive 'rust:' a fungus. In the above photo, we can see remnants of hawthorn fruits mottled by fungal strands.

 

The parsley hawthorn leaves show minor damage, but this year the fruits are a total loss.

 

The orange strings are tubes that release fungal spores into the environment. These spores need to land on an evergreen host  to continue their life cycle.

 

The parsley hawthorn lost a reproductive season, and the fungal infection is unsightly, but the overall health of this hawthorn isn't brought into question. However, multiple seasons of such abuse might very well undermine its longevity. Furthermore, this hawthorn isn't the only victim. Hawthorns, mayhaws and our lone crab apple tree have all suffered from this rust, or one of the several different rusts that are carried by the eastern red cedar (Juniperus virginiana). You can read about the ongoing battle on older blog posts, found here, here and here. In 2021, one healthy eastern red cedar, which was thoroughly colonized by one or multiple rusts, was removed from the catalogue. This past spring we identified another eastern red cedar, whose twigs are serving as hosts for these fungi; it might also be removed, in the hopes of protecting the diverse collection of hawthorns.

Tree of the Week: Soapberry (Sapindus drummondii)

There is one soapberry (Sapindus drummondii) in the arboretum collection. You can find it at the northern edge of the arboretum, towards the Hargrove band shell.

Without the aid of a ladder, all of the soapberry branches are out of reach, and it's necessary to crane one's neck in order to appreciate the leaves. So, passersby primarily see this: gray, flaking, bumpy bark of the trunk.

If you want to see soapberry flowers, now is the time. They most likely won't call your attention; you will need to go looking for them, as they are up above and hidden among the compound leaves.

The tiny white flowers are numerous and are clustered together on panicles. This photo was taken with the aid of a ladder. Perhaps you know of a soapberry tree whose flowers can be found near the ground?

A twig was snipped for further inspection.

Compound leaves alternate along the twig.

These leaves all measured under a foot; however, it's easy to imagine a soapberry leaf stretching out a couple more inches.

At first glance, leaflets appear to be opposite from one another, but looking closer we see that the leaflets irregularly alternate.

Leaflets are dark green and vary in size. They have an asymmetrical shape, and edges are smooth.

This particular panicle of soapberry flowers measured nine inches long. No fragrance was noticeable.

Only one soapberry was ever collected for the arboretum catalogue, and this is it. You can read more about it here. It has been successful and easy to maintain, suggesting that we ought to consider adding another soapberry to the landscape. Since this particular soapberry was purchased from South Carolina, it would be beneficial to collect an individual from northwest Louisiana.