Thanks again Wile E. Coyote!.. Now compiles!!.. Just in case I will leave here the proper makefile.
###################makefile##############################33
OBJDIR = $(GARFIELD_HOME)/Object
SRCDIR = $(GARFIELD_HOME)/Source
INCDIR = $(GARFIELD_HOME)/Include
HEEDDIR = $(GARFIELD_HOME)/Heed
LIBDIR = $(GARFIELD_HOME)/Library
CXX = g++
CXXFLAGS = -g -Wall -fPIC -m64
LD = g++
SOFLAGS = shared
# Compiler flags
CFLAGS = -Wall -Wextra -Wno-long-long \
`root-config --cflags` \
-O3 -fno-common -c \
-I$(INCDIR) -I$(HEEDDIR)
# Debug flags
CFLAGS += -g
LDFLAGS=-L$(LIBDIR) -Wl,--whole-archive -lGarfield -Wl,--no-whole-archive
LDFLAGS+=`root-config --evelibs` -lgfortran -lm -lz
garfroot: garfroot.C
$(CXX) $(CFLAGS) garfroot.C
$(CXX) `root-config --cflags` -o garfroot garfroot.o $(LDFLAGS)
# $(CXX) -o garfroot garfroot.o $(LDFLAGS)
rm garfroot.o