One week work placement at the National Botanic Garden of Wales

Catherine CutlerEden Project

June 2011

Reason for spending a week at (National Botanic Garden of Wales) NBGWI have recently moved into my current position as supervisor of the Mediterranean biome at The Eden Project (Eden), however the majority of my experience pertains to tropical and cool temperate environments. Additionally, although over the years I have made efforts to visit many different wild and cultivated areas and gardens I haven’t as yet spent a chunk of time in another botanical garden greenhouse setting.

Aims of the placement# To study how the different environment within the Great Glasshouse affects plant growth and development compared to that within the biome at Eden. (The NBGW glasshouse structure is clad in glass and fans provide air movement inside whereas Eden’s biomes are clad in three layers of plastic and there are no fans.) # To learn about the cultivation and maintenance techniques used by the Great Glasshouse team for their collections. Particular areas of interest will be annual pruning regimes, feeding regimes, pest control, changing displays and plant records. # To observe how the Glasshouse team at the NBGW work, the extent of their roles, how much and in what forms of interaction there is with the public/education/other projects, what training is in place and looking at what lessons can be learnt to improve my and my team’s role at Eden.# To visit the nursery at the NBGW and understand the systems used ‘behind the scenes’.# To become familiar with a range of unfamiliar Mediterranean plants not grown in Eden’s biome (the NBGW Great Glasshouse includes Australian, Canary Isles and Chilean areas not present in Eden’s biome).# To build links between Eden and NBGW. To share knowledge and discuss issues / problems of maintaining plant collections, managing high tech greenhouse structures, overseeing a team (and volunteers) and being part of a varied and popular visitor destination with all of its implications.

Support of the placementThe placement was only made possible by the funding provided by The Professional Gardeners Guild Trust (Finnis Scott Award); by Eden for making the time available and by the NBGW for being agreeable.

Summary of the placementPut simply, it was fantastic! Spending time with the team at the NGBW was both a complete delight and incredibly interesting. Spending time in a different botanic setting was both refreshing and inspiring. Time and time again we discovered that issues at the NBGW were the same as those being faced at Eden, which led to good encouraging discussion.

Diary of the weekThe majority of the week was spent with Marilla Burgess, team leader of the Great Glasshouse, with a few chunks of time spent with other team members Monday: Travelling from Cornwall to Wales, tour of the nursery, gardens andGreat Glasshouse by Ivor Stokes, Curator NBGW. Meeting of the NBGW team, including Marilla.Tuesday: Selecting plants from the nursery for planting out. Completing plant movement forms. Planting up and weeding the boulder garden. Exploring the outside gardens.Wednesday:Exploring the nursery. Clearing rubbish / compost material from glasshouse and boulder garden. Planting up and weeding in the Wallace garden. Pruning Australian shrubs (listed below) in the great glasshouse. Tour of the science, lab and library facilities. Thursday:Tour of maintenance and environmental control areas hidden below the Great Glasshouse. Watering the glasshouse, pruning Australian shrubs and removing excessive Chasmanthe.Friday:Watering and planting up in the Great Glasshouse. Removing excessive Pelargonium. Discussion and comparison of horticultural team structure and pay scales across the two gardens with Ivor and Angela (outdoor team leader). Collection of Protea seedlings, brought as seed from Kirstenbosh, and Eucalyptus ficifolia plant as donations to Eden.

IntroductionThe NBGW was opened in 2000 and boasts a range of outdoor themed gardens, water features, a double walled garden, historic parkland and the Great Glasshouse on a beautiful 560 acre site. The garden attracts115,000 visitors per year and is the most visited Welsh garden. The oval glasshouse is the largest single span glasshouse in the world at 110m long and 60m wide. It is a Mediterranean climate glasshouse housing plants from Australia, Chile, California, the Mediterranean basin, the Canary Isles and South Africa, arranged in naturalistic plantings.

In essence Marilla looks after the Glasshouse, the Wallace Garden and the boulder garden single-handedly. She has some assistance from students and volunteers but no skilled horticulturalists permanently working with her. Initially I was quite shocked at this, and this meant that I was even more interested in how she manages the spaces. By contrast at Eden I have 3 full time team members maintaining only the Mediterranean Biome (a larger structure which includes many crop plantings and large areas devoted to changing displays). Comparing and contrasting the two greenhouses based on many different criteria was very interesting.

Throughout my time in the Great Glasshouse Marilla and I spent time discussing our management practices. We were very much in agreement with how these plant collections should be maintained, pruned, watered etc. This time was so valuable to me and I really thank Marilla for sharing her thoughts and her time with me. It was great to talk to someone else in the same position. Our conversations and discussions have substantially increased my confidence levels within my own role at Eden. I hope that Marilla will have the opportunity to visit Eden.

Details from the week, areas of observation/discussionThe Great Glasshouse structureWhat a beautiful building! The elegant arch of the roof and the way the glasshouse sits in the landscape is magnificent. Additionally the glass cladding, situation and aspect allows far higher light levels than Eden’s ETFE-clad, cliff hugging biome. The results are obvious – the plants are growing well without the long soft etiolated growth experienced at Eden. Flowering was fantastic too, with vibrant displays. I was very envious!

Watering of the Great GlasshouseThe Glasshouse did not have automatic irrigation systems installed when it was built, as it was thought hand watering would be more reliable. Retrospectively drip lines have been installed into a large number of beds. These are used successfully, each being turned on by hand for about 1 hour. per week. At Eden most of the biome had automatic irrigation (pop-up sprinklers and drip lines) installed at the on-set but over the years the majority of the systems have been switched off or broken down. Now hand watering with hoses and portable sprinklers takes the whole team three mornings a week. I have been keen to ‘wean’ areas down to only being watered once a week and have been successfully trialling this in our California area. Observing Marilla’s success of a once a week watering coupled with our own attempts I feel I need to spread this management into other areas of the biome.

Weeding in the Great GlasshouseWeeds were few and far between in the glasshouse – seriously impressive! At Eden we spend a substantial amount of time weeding. What is in the glasshouse however is a very deep stone mulch, across virtually all the beds. Although Eden has beds where this would not be appropriate it has led me to consider extending our own stone mulches to keep weeds down.

Feeding of plants in the Great GlasshouseMed climate plants are typically adapted to low fertility, the plants in the Great Glasshouse looked good with very little feed. Although there is a facility beneath to inject feed into the entire water supply this hasn’t been used. Liquid feeding by dosatron of Vitax 1:1:1 and 1:0:1 occasionally takes place. The soil was gritty and poor but new plants have a little compost added at planting to assist establishment. At Eden more feeding takes place on the crop displays but the wild areas have a similar no/low feeding regime.

Cleaning of the Great GlasshouseThe glasshouse looked really clean and tidy. Marilla and her ‘team’ daily use a shred n’ Vac (made by Echo) to suck up any dust/leaves or debris on the paths. The housekeeping team also mop the slate flooring. We currently use a leaf blower to blow leaves/dust back onto our beds but I was very interested in the better result of the ‘hoover’, even though it can sometimes be problematic.

Pest control in the Great GlasshouseAs at Eden, integrated pest management results in spot-treating outbreaks using ‘soft’ chemicals such as soaps and oils coupled with the introduction of biologicals through the season. There were no particular outbreaks at the time I was visiting and generally pest levels were low. Currently there are poor quarantine facilities at the NBGW nursery which is of concern to the team.

Back of house for the Great GlasshouseMarilla was happy for me to have a poke around behind the scenes! The Great Glasshouse has an area within the walls devoted purely to the horticultural team which, although an odd shape and height, was fantastic to have. There was space, for instance, for all the irrigation bits to be kept in separate containers for easy selection. At Eden our back of house area is also used by catering, stewards, educators, maintenance, ITC, training courses, events and anyone else who may be doing anything in the biome! This can cause major problems for the horticultural team, particularly in the busy spring period. Experiencing Marilla’s back of house area has, yet again, caused me to consider ways of improving our space – with some ideas now progressing. However, the great Glasshouse does not have a vehicle for its sole/primary use and this leads to piles of prunings being piled up at the visitor entrances until a vehicle can be borrowed. Considering the Great Glasshouse is one of the key visitor points at the NGBW I was surprised at this. The material from the whole garden is collected into skips and taken away to the local council compost yard and green waste is bought in. There was disgruntlement within the team that composting wasn’t being done in house but economically this proves the best approach. At Eden, although done in house, its not perfect either, with no purpose built facility, so it was good to share some thoughts on this.

Environmental control of the Great GlasshouseBelow the glasshouse is a surprisingly large area of store rooms and staff areas. It is shame that, due to poor access, the area is somewhat under-utilised. All of the controls of the glasshouse are found down here. It was apparent that the system is capable of many fine degrees of control but the horticultural team, just as at Eden, do not input much into it; seemingly because the system works, there is little interest in the technological side of things and possibly fear of ‘messing it up’. I’m sure there would be potential to improve the use of the controls at both sites.

Nursery links with the Great GlasshouseThe NBGW has its nursery right next to the garden and the lunch room, making it a breeze to keep a close eye on the back of house collection and to select plants as and when required for the glasshouse. Due to staffing issues propagation of the glasshouse plants for rejuvenation of the collection has been fairly erratic. Eden has had exactly the same issues so it was nice to know we’re not the only ones! Historically the nursery propagator would visit the Great Glasshouse weekly and had begun to develop an understanding of how plants grew and the quantities that were required (it seems a ubiquitous problem that propagators just can’t stop themselves from propagating far too many plants!) I was impressed that the collection held at the nursery for the glasshouse is arranged in geographical areas and all the plants are on raised benches, both of which make the collection easier to manage. The collection of bulbs, well top-dressed with grit, has inspired me to improve our collection of flowering bulbs at our nursery, to come to the biome to be plunged whilst flowering.

Plant collection within the Great GlasshouseIt is always a delight to visit other gardens and see new plants. There were many in the glasshouse that were new to me, some that we will be keen to add to our own collection, and some that have helped me to identify unknowns amongst our collection.

Leschenaultia biloba

Chamaelaucium unciniatum

Darwinia citriodora

Anigozanthus flavidus

Sollya heterophylla

Protea aristata

Melaleuca thymifolia Banksia sp.

Hardenbergia violacea

Anigozanthus sp.

Pimelea ferruginea Psoralea pinnata

Chrysocoma coma-aurea

Verticordia plumosa

Mimetes culcullatus

Mirbelia dilatata

Isoplexis isabelliana

Catering within the Great GlasshouseI was very interested in observing the impact of the ‘Med Café’ within the glasshouse because during the week I was visiting a large decking eating area was being built in the Mediterranean Biome at Eden. The café had an impact in a number of ways – plants being walked on, rubbish left lying about, cables trailing over the planting etc. It became apparent that Marilla was the only one bothered about the presentation, ensuring the tables and chairs were in the right locations so as not to obscure the plant collections, and suitably arranged for visitors enjoyment. Team members from other teams had ‘different’ priorities. Pre-warned is pre-armed! On returning to Eden I have endeavoured to liaise with the catering team, hoping to ensure our new Med biome café is well presented at all times.

Communication within the NBGW horticultural teamAs at Eden, the radios that all the team members should carry are unreliable and as a result many team members aren’t contactable through the day. However the mess room is close to the main garden, nursery, stores and back of house areas and the team start and finish their days and take breaks there, so there is plenty of opportunity to catch up. The horticultural team don’t share this area with any other team and I became very aware of how this affects their interactions. Many conversations were horticulturally based and there were general discussions about plants/techniques. This is sadly lacking at Eden, primarily because we share a mess room with the whole Eden team and rarely spend time as a team without members from other teams (e.g. events, exhibits, stewards, retail etc.) with us.

Communication with other teams at the NBGWHowever, I noticed how little interaction there was between the horticultural and other teams at the NBGW. I felt that the horticultural team wasn’t as well integrated with the rest of the garden team as it could have been, the flip side of having a horticultural area separate to the other teams.

Team structure and responsibilities within horticulture at NBGWBoth gardens were in the midst of pay and progression reviews of the horticultural teams. It was interesting to discuss the horticultural team structures, pay and the job roles at different levels. In essence the roles of the Eden supervisor and NBGW team leader were fairly similar, including an observable difference in the leading, higher management and/or planning responsibilities between individuals. However the horticulturalist structure was very different, with Eden having six bandings compared to just one at the NBGW. Apprentices and maintenance / exhibit / education /interpretation responsibilities were also discussed. Hopefully these discussions will all add to the future planning at both gardens.

In conclusionThe week at NBGW was really enjoyable and eye-opening. It was quite incredible how many similarities there were, good and bad, and great to see how a different team in a different location operates. Personally my knowledge, experience and confidence of managing a protected Mediterranean collection have increased.

With thanks To the horticulture team and my housemates at NBGW for making me so incredibly welcome – your friendly welcome made the week great! Particularly to Ivor for his enthusiastic response to the visit and Marilla. To the curatorial team at Eden for encouraging and supporting me.To The Professional Gardeners Guild Trust (Finnis Scott Award) for making it financially possible – thank you!

Australian shrubs pruned:Myoporum parvifolium, Chamaelaucium uncinatum, Calothamnus sanguineus, Calothamnus quadrifidus, Boronia heterophylla, Grevillea levis, Darwinia citriodora, Melaleuca pulchra, scabra & fulgens, Callistemon, Hakea suaveolens