Arboretum & Botanical Garden Bulletin Board
Plant of the Month
Golden Mugo Pine
Pinus mugo ‘Aurea’
Location Grid P9 West side gravel road, just south of the gabion wall
There are some conifers in the collection that might appear to be hungry to most people this time of year. They turn various shades of yellow when temperatures drop. Some cultivars have been selected from different species that happen to exhibit exceptionally intense color.
The color change is completely temperature dependent, and as soon as temperatures warm up in the spring, the color turns back to normal green. I don’t know the exact biochemistry involved but essentially the plant is unable to metabolize chlorophyll as well in cold temperatures. Since chlorophyll is the primary pigment causing the green color in plants, when there is less of it the plant looks less green.
My experience with this one and the other species with the same trait is that they also tend to be more compact or dwarf than others in the same species that don’t turn yellow. Presumably that has something to do with the reduced chlorophyll, probably results in less photosynthesis to produce the energy necessary for growth. The Golden Mugo Pine in the Arboretum was planted in 2008 and it has not been significantly pruned in that time.
Monthly Projects
December continues our trend of remarkably mild weather with very little sign of winter. I can take some credit for the lack of snow because I invested in a fancy new electric snowblower at home, virtually guaranteeing a winter with no significant snow.
The nice weather has made it hard to sit in the office and try to catch up on neglected desk work. With help from Lucy Falcy, I have been able to work out plans for next year’s annual bed, sunflower forest and various other plantings. Some of those will be grown from seed in the Facilities greenhouse this winter, others are purchased as plugs from several different growers from all over the country. Every year I vow that I will start the process earlier, as often many of the newest, most popular varieties are already sold out by this time of year.
Upcoming Events
- No current events
When visiting the Arboretum, please remember that for your safety, the safety of others and for the protection of wildlife and plant collections, no pets are allowed. Ice on ponds is very unstable—stay off the ice.
