Catawba rhododendron bushes can reach a height of 6'-8' with a spread of 4'-6'. Displays are most effective when rhododendron bushes are massed together. These are poisonous plants -- do not allow children to ingest any of the azaleas or rhododendrons.
Best Answer: Tornadoes are caused by winds. When a tornado forms the wind pressure around the tornado drops and that's what you see on the barometer, the pressure goes down.
A tornado begins in a severe thunderstorm called a supercell. A supercell can last longer than a regular thunderstorm. The same property that keeps the storm going also produces most tornadoes. The wind coming into the storm starts to swirl and forms a funnel. The air in the funnel spins faster and faster and creates a very low pressure area which sucks more air (and possibly objects) into it. Tornadoes can form any time during the year, but most form in May. But, more severe ones form earlier because the most damge is caused in April. The more north you go, the later the peak tornado season is. This is because it takes longer to warm the northern parts of the plains so tornadoes form later.