Exegesis:

eipen de pros ton ampelourgon ‘and he said to the vinedresser.’

ampelourgos ‘vinedresser,’ ‘gardener.’

idou ‘look here,’ emphatic introduction of what follows, cf. on 1.20.

tria etē aph’ hou lit. ‘(it is) three years since,’ meaning here ‘for the last three years.’

erchomai zētōn lit. ‘I come seeking,’ here denoting acts (i.e. coming and seeking) that have been done during the last three years and are still in process. For the relationship between participle and main verb, cf. on v. 6.

ekkopson [oun] autēn ‘so cut it down.’ For ekkoptō cf. on 3.9.

hinati kai tēn gēn katargei ‘why does it waste the soil?,’ rhetoric question to which the answer is, “there is no reason”.

hinati lit. ‘for what reason,’ hence ‘why.’ Here it is reinforced by kai.

katargeō ‘to make ineffective,’ here of a tree, ‘to use up,’ ‘to waste.’

Translation:

Lo, see “behold” in 1.20.

These three years, or, ‘already as-long-as three years’ (Bahasa Indonesia RC), ‘these three years successively/time-and-again’ (Toraja-Sa’dan).

For to cut down (a tree) see 3.9.

Why should it use up the ground? has been rendered variously, e.g. ‘why does it occupy room (or, spread-itself here, or, on the land) uselessly?’ (cf. Kele, Pohnpeian; Toraja-Sa’dan, Malay), ‘why does it keep other things out of the place?’ (Shona 1966), ‘why does it use-up food in earth?’ (Kituba), ‘why does it exhaust (lit continually-eat-up) the soil?’ (one West Nyanja version, similarly Bible de Jérusalem), ‘is not this occupying good soil?’ (Lomwe), ‘why should it merely take-away the fertility of the soil?’ (Balinese); or, as a statement, ‘in vain it takes-up (lit covers) space’ (Tzeltal), ‘it is making the soil worthless’ (Yao).

Quoted with permission from Reiling, J. and Swellengrebel, J.L. A Handbook on the Gospel of Luke. (UBS Handbook Series). New York: UBS, 1971. For this and other handbooks for translators see here . Make sure to also consult the Handbook on the Gospel of Mark for parallel or similar verses.