Q & A from the Miller Library ’ s Plant Answer Line
QUEST FOR GOLD : LARCHES and FALL COLOR
B y R e b e c c a A l e x a n d e r | P h o t o s b y N i a l l D u n n e
This regular column features Q & A selected and adapted from the Elisabeth C . Miller Library ’ s Plant Answer Line program . If you ’ d like to ask a plant or gardening question of your own , please call ( 206 ) 897-5268 ( UW Plant ), send it via the library website ( www . millerlibrary . org ), or email directly to hortlib @ uw . edu .
QUESTION :
When do larch needles typically turn gold / yellow ? ( I have deduced from my limited reading that a frost is not required ...) Which kinds of larches grow here in Pacific Northwest ? I am passing through town and am wondering if you still have golden larches at the Arboretum ? I look forward to hearing from you . Happy Halloween !
ANSWER :
Fall color on Japanese larches ( Larix kaempferi ) in the Pinetum at Washington Park Arboretum .
( Photo by Niall Dunne )
During the pandemic lockdown , people have been eager to get outside and experience the wonders of nature . This became especially clear at the Plant Answer Line last fall , when we received lots of questions about the color change of larches . I ’ ve bundled some of them together below .
TIMING Halloween was a little late in last year ’ s larch fall-foliage calendar . The brilliant golden hues of the larches ( Larix species ) peaked around late September to mid-October . As is the case with other deciduous trees ( larches are deciduous conifers ) that undergo an autumn color change , the peak time depends on several factors . The primary and stable factor is longer nights , as hours of daylight grow shorter . Weather is another factor , and because temperature and moisture levels vary from year to year , so too does the timing of the color changes . In general ,
14 v Washington Park Arboretum Bulletin