Hiring the right pruning professional is critical for the health of your trees and safety of your home, according to industry experts and highly rated Angie's List tree service companies. Both the Tree Care Industry Association and the International Society of Arboriculture educate and oversee tree care experts, albeit in different capacities.

ISA certification recognizes individuals who have years of experience, passed a comprehensive exam, and continue their education every three years.

"Certification is an assurance for the homeowner that the person they hired knows what's best for their trees," says ISA spokeswoman Sonia Garth. The group also offers professional memberships (not to be confused with certification) for an annual fee to keep affiliates informed of industry news.

TCIA accreditation is awarded to companies that adhere to a checklist of items that include ethical business practices, consumer satisfaction and maintaining an ISA-certified arborist on staff.

"TCIA requires companies to meet industry standards for performance of tree care and safety," says spokeswoman Amy Tetreault. "It's a national program that has routine on-site inspections and a complaint response system."

ISA-certified arborists and TCIA accredited companies must also follow a code of ethics. Tree topping violates national pruning standards, therefore even advertising topping services could be considered an unethical practice, according to Garth.

"If a customer files a complaint, there's an arbitration process and if it's a true violation of ethics, that professional's certification could be revoked," she says.