Landlord insurance is needed if you are regularly renting out a property. Your homeowner policy likely will not cover your property if it is discovered you are renting it out. Unless it is for a special event, and is a rare occurrence. You do not want to be in the position that your insurance company covers nothing in a loss because you were renting your home out.
However, there are a lot of different options in Landlord insurance. There are many things you will want to consider with landlord insurance. Does it cover the dwelling if the renter is at fault? If someone is injured, is that covered? Does the landlord insurance policy cover against vandalism? You might also check to see if coverage is available to cover the cost of stolen items. Does your policy help cover costs in prolonged repairs/vacancy? Does your policy cover tenant damage and theft? What if your water heater breaks due to negligence and destroys a tenants belongings, does the landlord insurance policy you are considering cover these costs? Does the policy offer rental guarantee? Does it cover natural disasters such as storms, floods, and the like?
Those are just a few of the things you should consider. It is best to have a firm idea of the coverage you want and to get several quotes. You can put those quotes into a spreadsheet to compare them. This is easiest though if you can get the quotes for the exact same things. In our experience it is hard to get the quotes on the exact same coverage because each insurance company wants to handle things a little differently. The closer they are though, the easier you can compare pricing.
Also, before choosing an insurance company to get your landlord insurance from make sure to look up reviews and read reports on the company. This may seem like a lot of work but no one wants to be left uncovered when problems strike. A bit of extra legwork now may save you a lot of money and pain further down the road.