Trekking in the Rhododendron Forests of Nepal

Garth Wedemire September 2004

Garth is President of the Fraser Valley Chapter.

Bill McMillan is Vice-President of the Victoria Chapter

Garth Wedemire, a retired educator from Maple Ridge, decided impulsively at a Vancouver Island rhododendron meeting to join a group on a Rhododendron Trekking Expedition to Kathmandu, Nepal  and beyond to the South East Ana'purna Region in the Spring of 2003. Meeting together for the first time their group visited the Kathmandu Botanical Gardens where unexpected flora from varying regions of the world were on exhibit: cacti, hibiscus, morning glory and more. From then on the vegetation on the steeply terraced slopes would give way to sustenance foods for the Nepalese people and the glory of the arboreum and oak forests. Garth and his group kept away from the dangerous trekking areas where Maoists rule with guns. Sadly today from recent TV coverage, even Kathmandu is not safe with the instability caused by the rioting Nepalese over Iraq. Garth donned his various pack sacks, hung prayer flags in our meeting hall, showed us the double triangled Nepalese flag and advised any who might wish to attempt such a trip to buy well made walking poles to assist with the verticality and ankle twisting rock steps up and down the valleys.

They visited Stupas where the white tinted base represents the four elements: earth, air, fire and water amid lines of prayer flags with their printed mantras fluttering in the wind. They visited the sacred temple and stood under the watchful eyes of Buddha. They saw the prayer wheels where the sacred mantra is printed on scrolls inside the wheels and with every spin the message is sent out into the valley. They shopped at local stalls, saw clay pots drying, and women weaving on lap
looms. They made friends with the Nepalese children who were ever hopeful for 'bon bons' or money. Children at very young ages fetch the firewood and help with chores. The fog misted the view of the Himalayas as they trekked up and down, having to back track because of a washed out bridge and frightening landslides. One attribute needed in abundance was bravery!! In
all, they found four rhododendron species but they saw arboreum in multitudes, all in full bloom in the canopy, painting the mountain sides pink, red and the occasional 'alba.' R. companulatum , R. barbatum and the small alpine R. keleticum plus glorious magnolias: M .soulangea and M. napaulensis. Some Cobra plants in cool spots: Arisaema nepenthoides stood sentinel beside the trails. When the mist cleared and Garth used his telephoto lens, it was truly a Rhododendron Heaven.

His talk was both refreshing and educational and the slides which accompanied his adventures, with such smiling women and men in their 'middle age' (includes septuagenarians) were brilliant. I felt by the end that this was a rhododendron adventure with the purity of the snow on Fish Tail Mountain and whole hillsides of  R. arboreum var. roseum in full splendour in the foreground.

In the introductory talk, Bill McMillan spoke on Water Stress, a highly appropriate topic in this past season of drought with problems of both under- and over-watering.

In the unusually dry spring the shallow rooting nature of rhododendrons placed them at risk from wilting and leaf desiccation, problems intensified by the drying effect of winds. Consequently watering had to be started much earlier than normal.

At the Hort Centre this spring we started watering in April after noticing plants starting to look stressed (with droopy and curled‑up leaves). Despite this we still ended up with the edges of leaves on some plants drying out and later turning brown (i.e. Unique). Another symptom was stunted new growth on some plants. It really helps if you have a few ‘indicator plants’ – rhodos like oreodoxa, Cynthia, the large-leaf rhodos, and, at HCP, fulvum that let you know they are thirsty by drooping pathetically. Small leaf rhodos are slower to show symptoms and, according to Kenneth Cox small leaf varieties and evergreen azaleas are more drought resistant than most large leaf varieties (another plus for lepidotes!).

At home, I had some problems keeping potted plants moist enough despite running the watering system for 30 minutes on each sector every 3 days. I had to supplement with hand watering for plants in pots during the really hot spells. Unfortunately, we were away for a week at one point and I also missed a few plants with the supplementary watering. Some had variable leaf edge dieback, others lost all their leaves; fortunately, with some ‘first aid’ most have generated new growth and look like they will survive.

You can generally rejuvenate dry plants by watering but in the longer term, the stress might weaken the plant and could make leaves more susceptible to powdery mildew (ARS Journal this summer). As well, stressed plants seems to attract insects like magnets – the weevils have been very active in my garden this summer. I also think that insufficient watering reduces flower bud set so you get fewer blooms the following year.

At the other end of the scale, we overwatered certain areas at the Hort Centre, where drainage tends to be poor despite heroic amelioration efforts. During the hot spells, waterlogged roots and the warmth led to phytophthera development and we lost a number of plants to root rot. I’ve been working to improve drainage in the problem areas and hope to replace the present watering system with a drip and microspray system soon.

Cox (and Norm Todd too, I think) recommends an occasional good soaking rather than a series of quick ‘showers’ – an inch a week. About now, unless we have another dry spell, watering should be cut back to harden up new growth. Cox also argues that flower bud set is better if watering is reduced in late summer. It’s a balancing act, but if you find the right watering scheme, you should get healthy floriferous rhodos and the club should get fabulous spring flower shows.