As has been answered before, it won't start with the load on. One suggestion is to use a switch, which is constructed from a mercury or reed switch. This mercury switch is attached to a swinging piece of flat metal sitting at right angles to the wind. Once there is a strong wind, the flap will lift, the mercury will flow to connect the two leads and you can then switch all three phases at once to the load via a relay.
Gusts can be a problem. Imagine a dead prop and a gust, which does not last. The flap lifts and the load is on, dead prop again!
There are relays which take high AC voltage for the coil, so use one phase for the coil and let it switch all three phases. Hopefully the cut-in voltage of the relay is not too high, otherwise you miss out on heating while the prop spins without load.
Hope it helps.