Two trees with red leaves in the fall

Autumn's earliest reds in these two Kentucky natives

In the earliest days of autumn, red leaves appear within the tangled, brushy fencerows of rural Kentucky roads. These bright spots of fall color are often provided by two native trees -- sumac, in its several species, and sassafras. I enjoy seeing them progress into an overall state of crimson as the season continues.

Sassafras (Sassafras albidium) can grow to be a large understory tree (up to 50 feet tall) in the woods. The larger sumacs, such as flameleaf (Rhus copallinum) and staghorn (Rhus typhina), can reach 35 feet of height in ideal conditions, such as at the sunny edge of a grove of trees. However, in the fencerows along roads, these trees don't often attain such heights.

Along the county and state roads, the road departments use regular mowing, brush cutters, and herbicides to discourage woody growth. Our regional electric company uses a horrible, aerial "bush hog" under power lines. It chops and breaks every growing thing to a 10-foot height. Farmers repair their fences and clear the trees and bushes from the fencerows from time to time.

These sorts of setbacks don't kill out the sumac and sassafras. Both these trees have extensive root systems that will shoot up new trees. Individual stems may perish, but sassafras and sumac colonies will persist as long as their root systems survive to send up root suckers. That explains the widespread occurrence of these two trees in the fencerows.

In addition, both trees produce fruit that is eaten by birds. When birds rest and roost on the fences and in the bushy growth of the fencerow, seed-laden droppings fall to the ground. This is one of nature's methods of  planting new trees.

Sumac provides one of nature's most reliable autumn reds. The fall colors of sassafras include bright yellow, orange, red, and purple.

Twelve native trees with large surface roots

Bad choices for areas near paving or sidewalks

Due to their large roots at the surface of the soil, these trees are not suitable for planting near sidewalks or  driveways. They will cause problems if planted within "wells" in paved areas, parking lots, etc., and they will be increasingly difficult to mow around, wherever they are planted.  Be careful that you don't plant them where their roots will be a trial and tribulation in your life.

Red maple (Acer rubrum)
Silver maple (Acer saccharinum)
River birch (Betula nigra)
Hackberries (Celtis spp.)
Beech (Fagus grandifolia)
Sweetgum (Liquidambar styraciflua)
Southern magnolia (Magnolia grandiflora)*
American sycamore (Platanus occidentalis)
Pin oak (Quercus palustris)
Willow oak (Quercus phellos)
Live oak (Quercus virginiana)
American elm (Ulmus americana)

From a list in Trees for Paved Areas, a 2002 publication of the Virginia Cooperative Extension.  Non-native trees in the list include weeping willow, London planetree, and Norway maple.

*Your nursery may recommend cultivars of the southern magnolia that are supposed to have fewer surface roots. It would be a good idea to do some thorough research of the cultivar on your own, before planting .

Baldcypress at Lake's Edge

Three little trees I take an interest in

I've been watching these three young baldcypress (Taxodium distichum) trees for several years. They grow on the shore of Kentucky Lake near the Eggner's Ferry Bridge in Land Between the Lakes*. Turn off the road at the Fenton campgrounds, follow the road to the boat docks, and you can see them too.

When our daughter was attending college at Murray, KY, I passed through Land Between the Lakes whenever I went to visit her. I first noticed these little baldcypresses when I stopped to take some photos of Kentucky Lake on a windy day in 2007. Now our son is attending Murray State University, and I stopped to see how the little baldcypresses were doing when I drove home from Murray last week.

I was happy that the little trees are much larger than the last time I last saw them. I'm a little worried about the two smaller ones, though. I don't think their needles should be changing color and getting ready to fall off already. Certainly they are deciduous trees, but it's only the middle of August. I suppose they might have some kind of blight.

I suppose this will sound crazy. After all, these are baldcypresses, and they're supposed to be able to live in water. Still, I can't help wondering if constant submersion might be affecting the health of these young trees. When I first saw them, they were growing in wet soil at the water's edge. I think they are now standing in at least two feet of water. Kentucky Lake is full this year because we've had a wet summer.

I haven't found any information that I consider reputable about the tolerance of young baldcypress for growing in water most of the time. I did learn that baldcypress seeds will sprout in contact with wet soil, but not in water. As soon as they sprout, they start growing upward at a rapid rate; they elevate their photosynthesis organs (their leaves) as quickly as possible.

I read in Floridata's article about baldcypress that it grows faster, larger, and healthier when it doesn't have to tolerate floods. However, because baldcypress seedlings can't survive in heavy shade, they are usually  out-competed in moist upland forests. Thus, baldcypress is most often found at water's edge where it gets plenty of sunshine and a lot less competition, even if it doesn't thrive quite as well.

Baldcypress is famous for the knees that develop when it is grown in or near water. One theory is that the knees are pneumatophores (air roots that help the main roots with gas exchange when the tree is standing in water).  Another theory is that they function as anchors to keep the tree stable in ooze and muck. Whatever the knees do, I'm sure these babies are growing some.

*Kentucky Lake (created by a dam on the Tennessee River) and Lake Barkeley (created by a dam on the Cumberland River) are two nearly parallel bodies of water. Land Between the Lakes (LBL) is the 170,000-acre, mostly wooded, inland peninsula that lies between Kentucky Lake and Lake Barkeley. LBL is managed by the National Forest Service, and the dams produce TVA electricity.

How to compute a tree's critical root area

Protect tree roots during construction

It's vital to avoid disturbing or compacting soil around a tree that you want to preserve on a building site. The best way to prevent damage to a tree's root system is simply to fence out the critical root area -- that is, the area that contains the bulk of the tree's roots.

How to determine the critical root area:
1. Measure the circumference of the tree's trunk at 4-1/2 feet above the ground.
2. Divide the circumference by π (3.14) to determine the diameter of the tree's trunk.
3. Multiply the inches of trunk diameter by 1.5. (This gives you the critical root radius -- 1.5 feet for each inch of trunk diameter.)
4. Measure the critical root radius in all directions from the tree's trunk and compare the resulting circle to the tree's dripline. The larger of the two is the critical root area that should be protected.

Walking, driving, or piling construction materials within the fence should be absolutely prohibited. In addition, do not spill or allow runoff or buildup of chemicals, fuel, "cement water", sheetrock dust, etc. in the protected area.

Several university extension services have published some excellent information online about protecting trees during construction. These include:

• Preserving Trees in Construction Sites (pdf, 801K, Mississippi State University )
• Protecting Trees from Construction Damage: A Homeowner's Guide (University of Minnesota)
• Construction and Tree Protection (pdf 1.7MB, North Carolina State University)
  

Trees That Produce Root Suckers

Root-suckering trees can be a landscaping problem.

If you don't want to deal with root suckers (clone trees sprouting up from the roots of a "parent" tree,) don't plant the trees listed below. Some of them produce more root suckers than others, but all of them will send up shoots on a regular basis.

If you plant them, you can control the suckers by keeping the grass mowed around them. If you aren't vigilant, you may soon have a thicket or a pure stand. If you have a small yard, your neighbors will have to deal with the constant sprouting of root suckers from your tree also.

To help minimize root suckering, avoid any injury to the "parent" tree, such as pruning it or shearing off the tops of its roots with the lawn mower.

This is probably an incomplete list.

1. Alders --Alnus
2. Poplars --Populus -- cottonwoods, aspens, poplars (look for non-suckering varieties)
3. Sumacs -- Rhus
4. Willows -- Salix
5. Black locust -- Robinia pseudoacacia
6. Honey Locust -- Gleditsia triacanthos
7. Sassafras -- Sassafras albidum (Nutt.) Nees
8. Blackgum -- Nyssa sylvatica Marsh
9. Beech -- Fagus grandifolia Ehrh.
10. Southern Crabapple -- Malus angustifolia Michaux
11. Wild cherries -- Prunus serotina, Prunus virginiana, Prunus avium, Prunus padus
12. Wild plums -- Prunus americana
13. Lindens -- Tilia
14. Persimmon -- Diospyros spp.
15. Pawpaw -- Asimina triloba (will create a "pawpaw patch")
16. Devil's walking stick --Aralia spinosa
17. Common hoptree -- Ptelea trifoliata
18. Nannyberry -- Viburnum lentago
19. Blackhaw -- Viburnum prunifolium
20. Chinese mulberry -- Cudrania tricus pidata
21. Chinese jujuba -- Zizyphus jujuba
22. Juneberries -- Amelanchier spp. (serviceberries, etc.)

Particularly avoid these very invasive root-suckering trees:

1. White Poplar -- Populus alba
2. Russian Olive -- Elaeagnus angustifolia L.
3. Autumn Olive -- Elaeagnus umbellata Thunberg
4. European Black Alder Alnus glutinosa -- produces root suckers and spreads rampantly by seed
5. English Elm -- Ulmus procera
6. Mimosa - - Albizia julibrissin -- produces root suckers and spreads rampantly by seed