INTEGRITY IN ACTION
Thornton Plant Healthcare Company
Serving Thornton since 1978.
Ross Tree Company, a long-standing name in Thornton tree care since 1978, has undergone a significant evolution, transitioning from a general tree service business to a specialized plant healthcare company. Our shift represents a fundamental change in philosophy to proactive health and prevention rather than reactive tree services like pruning and removal. We are a licensed tree company with a strong relationship with the Thornton Forester Office, with a reputation for handling complex tree jobs, street closure permitting, and pioneering systemic injections to control tree insects. We strongly embrace standards-based pruning practices, which save our customers money in the long term. Why not call a licensed, insured, trusted tree and plant healthcare company with an A+ BBB rating? For convenience, we accept all major credit cards. Click the request service button above to fill out a request tree service form or call 303-871-9121.
Keep Informed About Trees
Ross Tree believes in educating its customers about tree and plant healthcare. Our general manager, an ISA-certified arborist, has over 30 video blogs on YouTube. Homeowners use the Ross Tree Insect Calendar to identify pests munching on their yard trees. We have posted over 80 blogs about trees on our website since 2019. Ross Tree sends out a quarterly email newsletter to its customers.
Thornton Tree Programs
Thornton Forestry is dedicated to the ongoing stewardship of trees throughout the City. Click here for more information about the City’s tree programs.
Emerald Ash Borer
Currently, the EAB is not found in Thornton, Colorado, but has been detected across the Denver metropolitan area. With confirmed cases in neighboring cities, experts consider it a matter of time before it arrives in Thornton. The time to act is now because Ash has no immunity to the EAB. Sheridan’s forester expects all property owners to manage and treat their Ash yard trees. Check out the Ross Tree EAB Handbook to understand your treatment options.
Tri-Level Fertilization Program
Ross Tree’s started its popular Tri-Level Fertilization Program in 2024. We use proprietary feeding formulations to help trees flourish in Denver’s arid climate and poor soils. The program has three feedings per year rather than two.

The Effect of Heat on Trees
High temperatures increase respiration in trees from leaves, stems, and flowers as they try to dissipate heat. Their porous lenticels also exchange gases between the atmosphere and their internal tissues. During hot days, trees release moisture into the atmosphere rather than using it for growth and storing food. Continuous hot weather stress trees as they two actives become out of balance.

Winter Tree Watering
In the winter, the root systems in deciduous and coniferous trees are active, so they need water. When temperatures are above freezing, their roots seek water and nutrients and store them so the tree can produce spring foliage.



Ross Tree Company

Ross Tree is a locally owned and licensed Denver tree company that has been in business since 1978. We offer proactive tree pruning, tree insect control, and plant health care services. Why not call a licensed, insured, trusted tree company with an A+ BBB rating?