By: Ana Sanchez Rivero, LCAM
I had a very difficult time passing the science courses in college. In fact I struggled so much that I had to drop it twice and failed a third attempt. I knew that it was impossible; certainly wasn’t for lack of trying. I was so pleased when I learned, that as an alternative, there was an Environmental Science class that could substitute the biology requirement; and an Environmental Pollution class that could substitute the chemistry requirement. I knew that was my way out. Those classes were by far the most enjoyable classes I have ever taken. Not only did it provide me with a thorough understanding of the native trees and plants to South Florida it also gave me a new appreciation for our environment.
So for this week’s podcast, I invited Henry Mayer of the UF/IFAS Miami-Dade County Extension to join us and talk about how construction and urbanization is affecting our environment and what we can do to safeguard and promote plant life. In particular there is a great concern that there is too much development and construction in South Florida and that it can have a detrimental impact one of our most valued resources, water. Per Henry, we have 5 million acres of lawn in the State of Florida and we need to manage our resources carefully to ensure that we are not wasting water. Water of course has a tremendous impact on our lives and provides a lot of the nutrients plants need to keep their cell content healthy.
It is important for those of us managing irrigation systems in our communities, be extra careful that we do not over water our plants. In conjunction to water, plants need good soil to provide plants with additional nutrients they need to grow. Henry further adds that non-native plants, such as Ixoras, Magnolias, Foxtails, and Gardenias tend to do very poorly in South Florida because our soil is very alkaline. He then clarifies that compacted soil, which means that the soil has lost all of its nutrients is caused by machinery, when you park your vehicle on the grass, or you regularly walk on a trail.
In addition to water, nutrients, and soil, a plant’s root system plays a major role in that plant’s sustainability. When seeds germinate, early in plant’s life cycle, they produce roots going down; but those roots in South Florida tend to die very soon because our water table is very high and they do not have enough oxygen. When this happens the lateral roots grow. Lateral roots are very close to the surface and are very important as they provide anchorage to the plant and tree, they allow for storage of nutrients, and help absorb water. Henry adds that most roots are in the top 2 to 3 feet of soil. There are some roots that often times grow above the surface. Henry informs us that this happens because the tree is looking for oxygen.
Unfortunately, in communities, lateral roots are a major tripping hazard. This is especially true in older communities where developers installed Black Olives because they grew fast and provided a lot of shade. A Black Olive’s root system is extremely invasive and can often times cause damage to plumbing lines, lift up pavement or sidewalks, and, in some extreme cases, the roots can cause structural damage. To help reduce liability in your community, you can cover the roots with either 1” to 2” of gravel or with no more than 2” to 3” of mulch. Because mulch decomposes it should be reapplied every 6 months. If the roots are so invasive that you must cut them, he recommends that you stay away more than 5 times diameter the trunk. He provided an example: a tree with a 20” diameter multiplied by 5 equals 100” or 8 feet. You should not cut any roots within those 8 feet that are close to the trunk. Those roots are anchorage roots and they help stabilize the tree. If these roots are cut the tree’s stability is compromised, especially with Tropical Storm or Hurricane winds.
And while we are discussing Tropical Storms and Hurricanes, Henry recommends that trees be trimmed before Hurricane Season. He stated that the general guidelines require that not more than 25-30% of canopy be trimmed in any one event. There are different techniques used by arborists to reduce the canopy but one cannot “hat-rack” the tree. He adds that arborists should provide specific information as to how the branches are going to be cut.
We all know that landscaping is one way to make a big impact on a community’s property values. In order to have a successful landscaping project, the way your trees and plants are planted play a big role. I know I have never had a green thumb; and have killed every plant I’ve ever received. I now know that it is because I was making my planting holes too deep. Henry informed us that you cannot plant trees too deep because this prevents the tree from getting the nutrients it desperately needs and the roots do not develop. The other consideration is the planting hole that has to be three times wider than the root ball. In addition, new plants need a lot of water for the plant to really grow.
The team at the UF/IFAS Miami-Dade County Extension is able to come out to your community, free of charge, to conduct an assessment of your common area and help you learn what you can do to improve the landscaping plan in your community. For additional information you may visit http://miami-dade.ifas.ufl.edu/. There is so much more information provided in this podcast, click here to listen to it in its entirety.
