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Q:   I am thinking about fertilizing my landscape plants and want to know what to use.

A:   The type of fertilizer depends on the type of plants and in most instances – slow release fertilizers can work best.  Generally, most of the landscape plants are fertilized in March.  You can make an application of fertilizer in the spring and again in the fall or make small applications throughout the growing season. We would recommend using an acid loving fertilizer for landscape plants such as azaleas, camellias and gardenias. In addition, this fertilizer can be used on typical hedge plantings too.  Acid loving fertilizer contains sulfur which will temporarily lower the pH allowing the plant to take up important nutrients. The ideal soil pH for azaleas is between 4.5 and 6.0.  If the azalea leaves appear yellow or have discoloration between the leaf veins it may be an indication the soil pH is too high or alkaline.  Many of our soils east of I-95 have tested high or alkaline. However, the only way to be certain of the soil pH is to have it tested.  We can do a soil pH test at no cost at either of the Extension offices (Yulee or Callahan). Just bring in one sample (about a cup) of the soil taken from 4-6 inches deep – do not scrape it off the top.  Both offices have a letter slot in the door so you can drop off a sample at your convenience. Be sure to include your name and phone number so we can contact you with the results.

Fertilizing palms is different and the University of Florida research recommends using only 8-2-12 starting in March, then applying again in June and September.  Any plant within 30 feet of the palm gets palm fertilizer.

Lawn fertilization begins on April 15 and goes through the growing season, applying fertilizer in small increments ending in September.  No matter what type of lawn, we suggest using 15-0-15 (N-P-K) or 16-0-8.  Never use more than twice the nitrogen (1st number) compared to potassium (last number).  Phosphorus recommendation is zero unless a soil test from the University of Florida demonstrates a phosphorus deficiency. We suggest allowing the grass to go dormant from October to March. However, March is the month to apply pre-emergent herbicides to reduce the potential for summer weeds. Another application of pre-emergent herbicides may occur in October if you have had a problem with winter weeds.  Attached is a list of pre-emergent herbicides for homeowner lawns.
Remember – please follow the directions on the label as “The Label is the Law.”  You can always apply less of the product or chemical but NEVER more.