With this season's heavy rainfall totals, your over watered plants can suffer from root rot.  While root rot is a more common problem with house plants, it can also be very prevalent in landscape plants that are growing in water saturated soils.

The primary cause of root rot on plants is poor drainage and over watering, basically causing the plants roots to sit in water for long periods of time.  An occasional event of heavy rains or excess watering is not enough to create a condition of chronically over watered plants that can suffer from root rot.  As well, more established landscape plants can tolerate longer periods of over watering more than newly installed plants that have not been able to establish a mature root system.

A healthy root system is vital to the life of your landscape or potted plant.  Healthy roots need oxygen to disburse water and nutrients to the plant in order for it to thrive and grow.  An over watered plant can suffer from root rot in two basic ways:  the available oxygen is pushed out by water, and as the roots sit in water, they will get "wet feet" or rot, similar to us if our feet sat in a tub of water for days and days.  As the roots start to die, they are unable to uptake water and nutrients, and the plant will eventually die.

An early symptom of root rot on a plant is yellowing leaves, which indicates that the plant is unable to draw up nutrients through it's roots.  An even more definitive symptom of root rot on a plant is leaf wilt, even though the soil is damp or has moisture.  This would indicate that the roots are unable to draw up water, because they are compromised and diseased.   In some cases, if the plant has value, a soil and root sample can be submitted to a lab for a pathology report, which would identify the particular type of root rot, and allow for potential chemical fungicide treatment.

For most landscape and potted plants, though, a visual examination of the roots is sufficient to identify root rot.  A healthy root system is white and present, whereas a root dying from root rot is black, brown, or non-existent, or has necrotic lesions throughout (see image above).

Many times, root rot can be avoided in potted plants by following a few simple steps:  Always make sure that your potted plants are potted in a loose, well-draining soil; if you use a saucer to collect water under the pot, never allow water to "stand" in the saucer; water your potted plants only when the soil is dry to the touch about 1" under the surface; use plant "feet" if needed, to keep the bottom of the pot elevated; add rocks or broken pot shards to the bottom of the pot before soil is added to aid in drainage.

With your landscape plants, though, it can be a little more difficult to prevent root rot when Mother Nature is in charge of the watering.  You may not be able to avoid over watered plants, but you can use these general rules:  Only irrigate plants when the soil is dry 1" under the surface; select plants for typically damp areas that are more tolerant of "wet feet" conditions; install plants flush with the earth or slightly above, and do not mulch heavily against the crown of the plant; add gutters or drainage systems in areas that have chronically saturated soils; recognize the early symptoms of root rot and treat with a root fungicide when possible and feasible.

If you can recognize the symptoms of and the causes of over watered plants that can suffer from root rot, you can take steps to prevent it.

Stink Vine (Paederia foetida) is an invasive weed in Florida landscapes, and it can be extremely difficult to control.  It is a fast growing, aggressive vine that both crawls across the ground and climbs into trees and bushes, eventually blanketing all with it's dense root system, tendrils and foliage.

Stink Vine (also called Skunk Vine) was introduced to Florida from Asia in the late 1800's as a potential fiber crop.  It quickly adapted to our climate, and within 100 years of it's introduction to our state, it was named to the Florida Noxious Weed List.  As if it's growth habit wasn't bad enough, it emits a pungent odor when crushed, hence it's fitting name of Stink Vine, or Skunk Vine.

Stink Vine is easy to propagate, starting with a simple seed dispersed by wind or bird, or even a small cutting left behind when trying to remove it.  Once a seedling is rooted, It crawls across the ground with little notice, entwines itself on the trunks of bushes, A/C units, gas lines, or anything, and before you know it, it is everywhere.  Even in your grass.  As it crawls across the ground, it roots into the soil at it's nodes, which then spider out to create new vines, of which they then repeat the process over and over again.  If left unchecked, Stink Vine will eventually choke the life out of your landscape plants by covering the desired foliage and inhibiting photosynthesis.

To control it, you must start with physical control....pulling it and tracing the vines back to the rooted tendrils and "mother plants".  Fortunately, the thin baby vines are white and easy to see, and they are rather tough, so they don't snap easily when pulled.  When you track them back to the source, you might find a larger trunk like the one in the above picture on the left.  If you can pull it, or dig it up with a hand shovel, try to get as many roots as possible, such as the photo on the right.  Once you are confident that you have pulled all of the runners, you can take a breather.  And, then wait for them to grow back, for your second wave of attack.

It won't take long for the new baby seedlings to emerge from the mulch or soil. It is at that point that you need to spray them with a weed killer that kills to the root.  Most systemic weed killers work by applying the herbicide to the leaf of the plant, so it won't serve any purpose to spray the tendrils or soil.  During our growing season of May-October, you may have to spray the weed killer several times, while watching for any runners that escape your attention and grow.  Those you will have to pull.

With a thorough initial clean up and removal of the Stink Vine, and follow up applications of a weed killer, you can control this insidious weed.  But, it does take diligence and perseverance!