CELEBRATING 26 YEARS! Welcome to My weekly series! ASK PROFESSIONAL Linda K. Lillie of Sprigs & Twigs Linda K. Lillie has been President of Sprigs & Twigs, Inc. for the last 26 years. She is a graduate of Connecticut College in Botany, an accredited NOFA Organic Land Care Professional, a Connecticut Master Gardener and a national award winning landscape designer for her design and installation projects. I've had this dogwood tree for over 20 years and it seems to be fine. However, in the last several years I've noticed this growth on it. Is this anything I should be concerned about? Maureen Dear Maureen - You have completely harmless Lichen growing on your tree. There is nothing you need to do and no need to get rid of it. Lichen is a unique organism because it's not just a fungus, but an alga as well that lives with the fungus symbiotically (when two different kinds of living things live together and depend on each other). The fungus part of lichen collects moisture which the alga needs and the alga creates food made from the energy of the sun for the fungus. Lichen is found in many places like on trees and rocks; in gardens they look wonderful on landscape rocks. Lichens are completely harmless to trees and although they are attached to the tree bark by "rhizines" which are hair-like roots, they do not penetrate deeply enough to cause any concerns. Lichen grows slowly and likes undisturbed surfaces, so you won't see it on species of trees that shed their bark frequently. Different forms of lichen have been all over the world for centuries, including the Artic and Antarctica. There are more than 15,000 types of lichen and estimates run as high as 6% of the earth surface is covered by lichen. Around the world, as far back as Roman times, lichens were used as dyes for fabric and in healing ointments. Lichens have even been found inside Egyptian mummies from 1500BC! Since the 1300's, lichens have been as the main source of dyes used in litmus paper, a paper testing strip used to determine pH. Today, they are used in perfumes and in dried flower arrangements as well as for miniature plant representations for model railroads. Lichen will only grow is areas where the atmosphere is clean, so it's a good sign and you can be happy that you have them growing on your property! Sprigs D&Twigs EMAIL OR MAIL YOUR QUESTIONS TO: info@sprigsandtwigs.net or Linda Lillie, Sprigs & Twigs Inc, PO Box 245, Gales Ferry, CT 06335 SPRIGS & TWIGS VOTED THE BEST BY DAY READERS EVERY YEAR! CELEBRATING 26 YEARS ! Welcome to My weekly series ! ASK PROFESSIONAL Linda K. Lillie of Sprigs & Twigs Linda K. Lillie has been President of Sprigs & Twigs , Inc. for the last 26 years . She is a graduate of Connecticut College in Botany , an accredited NOFA Organic Land Care Professional , a Connecticut Master Gardener and a national award winning landscape designer for her design and installation projects . I've had this dogwood tree for over 20 years and it seems to be fine . However , in the last several years I've noticed this growth on it . Is this anything I should be concerned about ? Maureen Dear Maureen - You have completely harmless Lichen growing on your tree . There is nothing you need to do and no need to get rid of it . Lichen is a unique organism because it's not just a fungus , but an alga as well that lives with the fungus symbiotically ( when two different kinds of living things live together and depend on each other ) . The fungus part of lichen collects moisture which the alga needs and the alga creates food made from the energy of the sun for the fungus . Lichen is found in many places like on trees and rocks ; in gardens they look wonderful on landscape rocks . Lichens are completely harmless to trees and although they are attached to the tree bark by " rhizines " which are hair - like roots , they do not penetrate deeply enough to cause any concerns . Lichen grows slowly and likes undisturbed surfaces , so you won't see it on species of trees that shed their bark frequently . Different forms of lichen have been all over the world for centuries , including the Artic and Antarctica . There are more than 15,000 types of lichen and estimates run as high as 6 % of the earth surface is covered by lichen . Around the world , as far back as Roman times , lichens were used as dyes for fabric and in healing ointments . Lichens have even been found inside Egyptian mummies from 1500BC ! Since the 1300's , lichens have been as the main source of dyes used in litmus paper , a paper testing strip used to determine pH . Today , they are used in perfumes and in dried flower arrangements as well as for miniature plant representations for model railroads . Lichen will only grow is areas where the atmosphere is clean , so it's a good sign and you can be happy that you have them growing on your property ! Sprigs D & Twigs EMAIL OR MAIL YOUR QUESTIONS TO : info@sprigsandtwigs.net or Linda Lillie , Sprigs & Twigs Inc , PO Box 245 , Gales Ferry , CT 06335 SPRIGS & TWIGS VOTED THE BEST BY DAY READERS EVERY YEAR !