After a tree has been planted and watered, mulch should be added to complete the planting.  Mulch is highly beneficial.  It can beautify your planting, suppress weeds, add nutrients to soil, alter pH, protect new plantings, retain water and even turn stone to soil.  Suppressing weeds and retaining water has long been a common known benefit of using mulch.  And no one can argue that a fresh layer of mulch doesn’t improve the look of any landscape.  But mulch has other benefits:


One of the greatest benefits of using mulch is its ability to protect both new and established plantings from damage.  Public enemy number one of newly planted trees is the string trimmer.  If you have a newly planted tree that is not growing well, check for nicks and cuts around the base of the tree caused by accidental strikes from the string trimmer.  When a tree’s bark is damaged, the tree’s transportation system and food supply are damaged.  The roots cannot get energy from the leaves and the tree may stop growing or sicken and die.  A ring of mulch around a newly planted tree or an established tree will protect the tree from being damaged.


For most living in South Florida, you know that our soil consists of limestone or builder’s fill (crushed limestone) with the occasional pocket of sand, marl or muck.  The residents of South Florida have managed to create beautiful landscapes by choosing plants adapted to growing in limestone or by altering the soil.  The rocky soil can be altered by applying mulch.  Mulch begins to solve poor soil problems from the moment it is applied and begins to decompose.  The more mulch you put down, the better it is for your plants.  The more times you mulch a year, the better it is for your soil.  Over time, you applications of mulch will do several things.  The acidic mulch will wear away at the limestone helping to create crevices and pockets in the rock which will be exploited by the roots of your landscape.  Mulch can provide a lower pH environment, which is more conducive to the uptake of nutrients, for the roots.  The naturally high pH (averaging 7.8-8.1 pH) of our limestone based soil makes micro nutrients such as iron and manganese unavailable to plants.  Your applications of mulch will decompose into rich, organic soil and will provide nutrients to your plants as the mulch decomposes.  Mulch will also act as a sponge, absorbing water and nutrients that would normally run off of the limestone and into the aquifer.  Mulch’s ability to hold on to nutrients will allow you to apply less fertilizer and water while maintaining a high level of nutrition in your garden.


You should mulch to a depth of six to ten inches annually.  Never mulch next to the base of a plant; this can cause trunk and root diseases and overall health problems.  Mulching too high next to plants can be avoided by simply pulling mulch away from a plant’s base in a ring after the mulch has been applied.  Extend mulch beds or rings laterally to a tree’s furthest reaching limbs (drip-line).  The greatest concentration of feeder roots occur at this point.There are many different types of mulch available to the homeowner.  Pine bark will keep its color longer than other natural mulches.  Leafy mulch will decompose faster than woody mulch.  Any mulch will be beneficial to your plantings.  Do not be afraid of mulch from tree trimmers.  Worries of “weed seed” being delivered to your yard by deliveries of mulch are often exaggerated.  Invasive seeds hidden in a mulch pile can be easily destroyed by composting the mulch before applying or by simply picking the weeds as they appear.  It is possible to bring in citrus canker in tree trimmed mulch and citrus owners should be wary of mulch from an unknown source.