Q: My boxwoods are dying. What might be causing this?

Boxwood

 

A:  This could be an indication of root decay but there are fungal pathogens which can also cause limb dieback. If possible, consider bringing me a clipping so I can better determine what might be the real problem. Limb dieback can be caused by over-watering, heavy mulching and over pruning. There are no chemical recommendations for this – just cultural changes:

 

 

1. Boxwood plants are drought tolerant plants – consider removing or capping the irrigation. Watering twice a week can cause some serious issues.
2. Mulch should not be touching the trunk of any tree or shrub and should be only 2 – 3 inches thick.  Over time, mulch layers can build up and contribute to root problems.  Heavy mulching should be removed.  There should be an area directly around the trunk with nothing but soil and air.
3. Consider allowing the shrubs to reach a slightly higher height to avoid over-pruning.

Q: My friend just purchased a Dioon palm. It looks like a sago palm to me. What is the difference?

Dioon_edule

A:  The Dioon edule is a cycad similar to its cousin the sago palm.  Dioon edule is also known as the Chestnut Dioon or Virgin palm.  Its origin is Mexico. In its homeland, Dioon is accustom to harsh, dry environments and shallow, sandy soils.  It is considered a good Florida Friendly Landscape (FFL) plant as it requires little irrigation. Typically it grows up to 8 feet tall and about five feet wide.  It does look similar to the sago palm but its leaves are more upright form and each leaflet is flat.  The leaves are generally produced in the late summer or early fall and are initially soft and feathery – they later harden and become sharp along the edges. Dioon produces no flowers but instead has a single cone in the center of the plant. This plant is being watched closely because most of its normal habitat is being threatened.  In some areas, it is considered endangered.  We have added it to the demonstration garden at the James S. Page Governmental Complex.  The purpose of adding the Chestnut Dioon to our demonstration garden is to get it established then determine if the plant might be a good specimen for our area.

Q: What can you tell me about the Florida sand pine?

Pinus clausa leaves

A:  The sand pine, Pinus clausa, is a native pine tree and a relative of the common Florida slash pine.  The sand pine has shorter needles, is shorter in height than its cousin and does not live as long as the slash pine.  Because it does not produce tall trunks, it is of little importance to the lumber industry except for occasional usage for pulp. However, it is very valuable to wildlife throughout the state.  According to the Department of Agriculture, sand pines play an important role in the lives of more than 20 threatened or endangered species as these animals live in or utilize sand pine forests. In addition, sand pines provide cover and nesting sites for many songbirds, woodpeckers and squirrels. Small mammals and rodents feed on the seeds which attracts large birds of prey. Sand pines tolerate most any kind of soil conditions except wet sites. Although, as its name implies, sand pines are found most often in coastal, sandy soils.  It can grow in most any type of light condition and is highly salt (aerosol) and drought tolerant.  Sand pines grow slowly with normal heights of 20 – 40 feet.  The needles of the sand pine are 2 – 3.5 inches long which is short when compared with the slash pine’s needle length of 7 – 12 inches.  Sand pines are not known for having a straight trunk and often will take on a “bonsai” look by growing more limbs on one side of the tree. This does not mean there is anything wrong with the tree.  It has few diseases problems which should make it a nice addition to landscapes along the coast as long as it is not over watered. The trees can be susceptible to bark beetles and sand pine sawflies.  There are two varieties of sand pine, the Ocala, found in most areas of Florida, while the Choctawhatchee sand pine is found further north in the panhandle area of Florida. The only difference between the two trees is the cones.  Ocala cones display a waxy covering and stay closed whereas the Choctawhatchee cones open up to expose the seeds.  The Choctawhatchee sand pines are often grown as Christmas trees. We just added the sand pine to our large demonstration garden at the James S. Page Governmental complex.  We will need to give it a year or so to see if it can adapt to a more urban environment.   https://edis.ifas.ufl.edu/pdffiles/ST/ST45800.pdf