R
Topping a plant can increase yield. If that's helping the plant, then yes. Otherwise, probably not much.
Are you sure the ground will be warm enough, in April, in Wash. state?
C
Yes the ground should be 50+ degrees by the time they are pretty much raised bed in natural organic mixed fertilizer soil.. our temperatures should be able to handle the weather and the plant will slowly get used to it.. they are tough plants.