A South African LongEZ crashed off the end of a 1700 foot rough field when the pilot attempted to take off with a quartering tailwind. The airplane accelerated slowly on the very rough strip and failed to lift off before running off the end of the strip into a marsh. The nose gear collapsed, the nose dug in and the airplane flipped. The pilot and passenger were both injured and the airplane badly damaged. This accident was one that need not have occurred.
The Long-EZ is not suitable for short rough fields. You can land a Long-EZ on a rough strip that you may not be able to fly out of. Remember, with a canard pusher configuration, such as the Long-EZ, you have no prop blast over the elevator, and therefore you can not force the airplane to rotate early and start the wings carrying the load. You have to accelerate to flying speed, 50 to 60 knots.
A rough field or even a grass field with long grass (anything over 2" long) will greatly add to the rolling drag and slow down your ability to accelerate to the point that you may need more runway than you have available. As long as you fly your Long-EZ from a hard surface or a smooth grass field at least 2500 feet long, you should have no problems. All aircraft are compromises, you cannot have a Lear jet and a J-3 cut in one aircraft. The Long-EZ is no exception. It does what it was designed to do very well. High speed, economical transportation is the Long-EZs forte.