Lemon Tree in Hebrew: Etz leemon. Tree: Etz, Lemon: Leemon. The Lemon Tree: Etz Ha-Leemon.
Gadol
strong body = goof chazák (גוף חזק)
You can use either Etz or Ilan.
The tree of life = etz ha-chayim (עץ החיים)
family tree = אִילָן יְוֹחְסִין שֶלִי (ilan yochsin sheli)
ba'al ratson chazak (בעל רצון חזק)
my big brother = achí ha gadól (אחי הגדול)
'Big tree' is 'Crann mór', 'old tree' is 'Seanchrann'.
Dreams look the same in Hebrew as in any other language. The experience itself is called "kha-LOME" in Hebrew.
Tree of life = ets ha-khayyim (אץ החיים)
There is no Hebrew expression for "tree hugger" in Hebrew, because virtually all Israelis regard trees with high importance. (it is illegal in Israel to cut down trees, with very few exceptions). You can translate this phrase literally as mechabek etsim (מחבק עצים), but it has a very comical sound in Hebrew.