proteas With Altitude Annual Report January – December 2020 Robbie Blackhall-Miles and Ben Ram

Abstract This report aims to show how the ‘ With Altitude’ project progressed during 2020, documenting the experiences of the project over the 12-month period. It provided an opportunity to review the ongoing process of managing the nursery site, analyse data gathered about the grown and set aims for the year ahead.

Background ‘proteas With Altitude’ is an ongoing research project, based in the UK, studying the horticulture of a wide range of cool growing montain species. In 2015, an initial expedition was undertaken to study in-situ and collect seeds of Proteaceae, growing at high altitude, in the of . One hundred and fifteen separate observations covering fifty-five distinct species were made, of which thirty species were collected as seed. A further collecting trip was made during December 2017 with 43 species being collected as seed, of which 16 were new to the project and 6 new to cultivation, with plants and cuttings of some species being imported under phytosanitary certificate. A full report detailing progress up to the beginning of 2020 can be found in the 2016, 2017, 2018 and 2019 annual reports. This report will discuss the period between January 2020 and December 2020.

Nursery Infrastructure This year, a hose adapter for the water storage tank was purchased, allowing plants to be watered with rainwater by hose rather than by watering can. This has reduced the amount of time it takes to water plants with rainwater. The tank got low occasionally but never ran out.

A new battery and thermometer were purchased for the weather station, allowing us to record weather once more. There is now a mobile phone connected to the weather station, enabling weather at the nursery to be monitored remotely by streaming data to the internet.

Germination Efforts to germinate seed in 2020 were concentrated on species which have previously proven difficult. This meant that of the 32 seed batches sown, only 9 batches had any germination. All germination happened between 17 and 41 days from sowing with seeds from each batch germinating over a period of 7 to 18 days. dregei had a 50% germination rate but then 40% mortality rate. Two plants of parilis germinated, both however both died soon after. Any germination for this species is useful as it implies that the germination method must work to some extent. pallasia also had germination, but both plants have unfortunately now died. recondita had a 40% germination rate. Germination was also achieved for Protea humiflora and Protea subulifolia. This brings the number of species of Proteaceae from South Africa covered by this project to 58.

Propagation by Cuttings During 2019 some success was had with production of plants from cuttings. Semi ripe material was treated with a rooting hormone and placed in pots of free draining protea compost. Successful rooting took place in a comparatively short period. Literature regarding the propagation of Proteaceae by cuttings suggests gentle bottom heat, so the decision was made to invest in a thermostat-controlled heat mat, covering just over a meter length of the nursery bench. Cuttings were taken from a range of species, giving priority to plants for which a back-up was needed due to low numbers in the collection and low likelihood of producing more from seed.

Success with this has been limited, with a lack of suitable drainage has proving to be a problem that we had not anticipated. This led to compost retaining water subsequently rotting many of the cuttings. It also led to a lack of callus formation and thus minimal root production. Some cuttings remained alive for most of the year, surviving only on a callus.

Cultivation FossilPlants is registered with the UK’s Animal and Plant Health Agency (APHA) and undergoes regular inspections for notifiable pests and diseases. The nursery is split into two areas with one area having a Polytunnel for receipt of new plant material. New plants are held here for a minimum of 3 months before they are moved into the main nursery area or into the garden. The main nursery area is fenced from the reception area and has increased plant health precautions including an entrance Chloroxylenol foot bath and all floor areas covered with a membrane that can be regularly disinfected.

An integrated pest and disease management system is used with prevention and biological pest control the preferred choice for any insect pests and disease. Chemical pest control is only used when other controls have repeatedly failed and is undertaken with the health of the plants and the wider biodiversity of the nursery site in mind.

Few pests have had significant impact for the proteas With Altitude project, with the most significant to date being Mealybug infestation and tortrix moth caterpillar. Other damaging pests have been Fungus gnats which particularly effect seedlings and mice which nibble emerging flowers. The control of pests such as Mealybug, Tortrix moth caterpillar, Fungus gnats (sciarid fly) and mice has had varying levels of success.

Tortrix moth has proven to be a pest for both plants outside and in our polytunnels. It has a particularly negative impact on Leucadendron but affects all Proteaceae species. The caterpillars use silk to bind leaves together at the growing tip of plants while they feed on the growing tip itself. This can be very damaging, but we have found that this problem is best controlled by picking off individual caterpillars by hand once noticed.

Fungus gnats eat plant roots, usually in wet compost, often when seedlings have been potted up. This can be avoided by having a free draining mix and placing pots on a bench that is free draining. This can also be a problem while rooting cuttings, particularly if a heat mat is used as this often impedes drainage. Using the insectivorous plant Pinguicula ‘Tina’ has proven the most effective way of controlling this pest. It is important to note that Pinguicula ‘Tina’ is a hybrid between two Mexican Pinguicula species and as such prefers to be kept dryer than most other carnivorous plants. We have also had success with Drosera capensis for controlling fungus gnats but not to the same extent as with the Pinguicula. The first signs of Mealybug are white cottony masses (egg masses) in leaf axils and subsequently the growth of sooty moulds appear due to the build-up of excreted honey dew on the leaves. Mealybug infestations seem to start by affecting plants in the polytunnels but will remain on the plant after an extended period outside. This is even the case on plants that have been outside continuously for over 12 months with rain and frost. The species of mealybug that affects the Proteaceae at the nursery has not yet been investigated. Picking off the mealybugs by hand is a time consuming, laborious, and painstaking work and is often an ineffective method of control in the long term but will reduce pest numbers temporarily. Releasing the larvae of the ladybird Cryptolaemus montrouzieri helps to control mealybug numbers through predation during the very short warmest part of high summer as they need temperatures of over 18C to be effective. We have found that Lacewing larvae, however, are effective predators of mealybug when the temperature is over 15C, allowing their use as a predator for a greater portion of the summer.

Many potted plants are housed in the polytunnel from late November to mid-April. During these cooler months as part of our integrated pest management strategy, spraying all plants in the polytunnel with the systemic neonicotinoid Bug clear ultra (active ingredient Acetamiprid), can help control severe infestations of Mealybug. This is done once at the beginning of this period, while the temperature is still warm enough for Mealybug to be active, yet late enough in the season to reduce exposure of pollinating insects and breeding birds. Plants in the polytunnel are then sprayed again when Mealybug activity is noticed due to increased temperatures towards the end of this period. Spraying is conducted by closing the polytunnel completely for 24 hours during and after spraying. To minimise the effect of this pesticide on other insects, spraying does not happen if plants are flowering and will not happen in the 3 weeks prior to plants being taking out of the polytunnel. The impact of this spraying reduces mealy bug infestation allowing mealy bug control by biological means through the rest of the year.

Mice are attracted to rodent pollinated proteas, such as and P. venusta, however rather than pollinate them will often chew on the flowers and nearby shoots. This has also been noticed on some species of Erica. Mouse control is undertaken as and when required. Traps are set near to plants liable to damage or once first signs of chewing are noticed. Traps are bated with peanut butter and in this way the offending mouse is usually caught. Mouse control is only undertaken when necessary.

When a plant dies in a pot it is our practice to investigate the rootzone for signs which might indicate the reason for death. Often an Earth Worm is found in such pots. Earth worms are rarely found in the compost of healthy plants or when a plant is potted up. Earthworms are known to eat plant roots when in pots and thus there may be reason to believe that earthworms have been a significant pest for us, especially for younger plants. Given that young plants are kept on benches the question of how they find their way into the pots remains unanswered.

One of the most notable deaths during 2020 was that of Leucadendron album. This otherwise healthy plant, which had easily survived a winter outside in the ground, died during a particularly warm period in August 2020, when sunny weather was interspersed with heavy thundery downpours. We can only attribute this to increased soil temperatures during that week. We aim to mitigate the impacts of increased soil temperature by growing ground cover plants which protect the soil from the effects of hot sun.

In our protea trial beds we are growing a wide range of other South African plant species to help shade and cool the root zone as well as for aesthetic appeal. Watsonia spp., Gladiolus spp., Pelargonium spp., Eucomis spp., Myrica quercifolia, Agathosma ovata, Kniphofia spp., Romulea komsbergensis, Lachenalia tubiflora, Widringtonia nodiflora, Polygala spp., Nemesia spp. and Diascia spp. are all used to varied degrees. A range of Pelargonium spp. and Erica spp. are proving particularly useful in this respect with one, Pelargonium alpinum, proving to be a good ground cover. Our Erica collection is growing and is becoming a focus for FossilPlants due to our involvement in the BGCI initiative, The Global Conservation Consortium for Erica. The South African biome has an unusually high level of diversity within Erica, and it has the highest species diversity and level of endemism of any in the fynbos biome. The Iridaceae, containing the genera Gladiolus, Watsonia and Romulea, is of high diversity within the Fynbos and many of the species have proved to form good companions to the cultivation of the South African Proteaceae.

Distribution of Plants to other Collections No plants were sent to other institutions during 2020 due to a range of issues related to the COVID- 19 pandemic and subsequent lock downs restricting certain activities. During September 2020, during a break between COVID-19 lockdowns, we visited RBGE Logan Botanic Garden and were able to see the plants that they are currently growing as part of the ‘proteas With Altitude’ project. Most of the plants were growing in the terraced area of the walled garden at Logan where they are able to get the maximum available sunlight. We were pleased to see many plants doing well however was suffering from wind rock from the strong winds that sometimes impact Logan and had died.

Protea cynaroides at RBGE Logan Botanic Garden John Grimshaw from the Yorkshire Arboretum reported that the Leucadendron spissifolium they received in 2018 was still thriving during 2020, having come through another winter in North Yorkshire.

Plants being grown in the heather landscape at the Royal Horticultural Societies garden at Wisley thrived during the summer of 2020 yet two growing near the Stone Pine café at Wisley died during the early part of the year.

We were also informed that there had been no losses at the Eden Project. Flo Mansbridge from the Eden Project wrote to say ‘they have put on lots of growth during lockdown and some flower buds are appearing’. Eden opened its new 800 square metre South African Veld exhibit during 2020. This new garden is inspired by the wide range of habitats in South Africa from the mountains to the coast. It is set just outside their Rainforest Biome – the world’s largest indoor Leucadendron spissifolium subsp. fragrans at the Yorkshire rainforest. arboretum The exhibit aims to draw attention to the fact that there are many species that are under threat in South Africa. Nearly a quarter of South African flora is considered either threatened with extinction or is of conservation concern. Press surrounding the opening of the exhibit referenced the ‘proteas With Altitude’ project and quoted Flo as saying ‘Among the very special plants being grown are Protea and Leucadendron from seed collected by Robbie Blackhall-Miles and his partner Ben Ram, who are based in North Wales and are carrying out conservation work with the Western Cape of South Africa’.

Thanks to the Eden Project for using this opportunity to highlight the conservation issues South Africa’s plant diversity face.

Flo Mansbridge in the Eden Projects new Veld exhibit ©Eden Project Flowering argenteus The silver leaved pagodas (Mimetes spp.) are a priority group for us, and we are very fortunate to grow 4 of the 5 species. All the silver leaved pagoda species are threatened with extinction. The silver pagoda (Mimetes argenteus) is globally Endangered with a small population of fewer than 600 plants and has an estimated extent of occupancy of only 124KM². Our plants of this species and two of the other silver leaved Mimetes species we grow came to us as plants grafted onto a root stock. They have proven extremely difficult to grow on their own roots in South Africa due to their susceptibility to the disease Phytophthora cinnamomi.

We have been working in collaboration with South African horticulturist Robbie Thomas to better understand the cultivation and particularly the germination of these beautiful silver plants.

Mimetes hottentoticus Mimetes hottentoticus was the second of the silver pagodas to flower during 2020. The matchstick pagoda is assessed as Vulnerable on the IUCN red list and has fewer than 2000 plants at any one time in the wild. It is threatened by invasive species and disease in its wild home in the western cape of South Africa. The large quantities of these species produce for their bird pollinators is an attractant to the common wasp (Vespula vulgaris) here in the UK. However, their extra floral nectaries on the leaves also attract many other insects such as the pictured Ancistrocerus wasp. Protea canaliculata Known as the groove leaved sugarbush, this species is globally assessed as Least Concern. The interest for us in this species is that it makes its home across the high mountains of the Western Cape from the Hex to the Swartberg where we found this species growing. It is found at elevations of between 700m and 1700m asl.

The Plant of Protea canaliculata that we have at our nursery is the only one to have germinated from the seed collection we made on the edge of the Swartberg Pass in 2015. Given that it germinated in 2016, we were surprised to see it flower in such profusion in 2020. Almost every individual growing point producing an . Another Protea species of note to flower with us during 2020 was Protea neriifolia. This was a plant that had originally been given to us and was grown from seed of unknown provenance. The photographs shown document a four-month period during which the inflorescence grew to a stage of being fully open by the end of December 2020. During this period, the plant experienced a few cold weather events with temperatures dipping to near freezing on 3 occasions.

Protea neriifolia in full flower and showing the impacts of frost Protea venusta Protea venusta is a high-altitude specialist found at elevations of 1700m to 2000m in the Swartberg and Kammanassie mountains. This species is red listed as Endangered, with its largest threats coming from climate change and non-native invasive species. A population decline of over 50% has been estimated by 2025 and already populations in the Kammanassie mountains, where we searched for it in 2017, have reduced dramatically. We grow two plants, one in a large pot outside year-round and one in the ground. These have a sprawling form which is true to type, as seen on the high ridges and summits. Upright growing hybrids between this species and occur naturally in the wild as described in detail in Mitchell, N. and Holsinger, K.E., 2017, ‘Cryptic natural hybridization between two species of Protea’. Seed of hybrid origin has been made available to horticulture but is often misnamed Protea venusta.

Spatalla incurva A target genus that was of particular note for our 2017 collecting trip to South Africa was Spatalla. Our gap analysis of cultivated South African Proteaceae found that only a limited number of Spatalla species were cultivated, that a quarter of the Endangered and Critically Endangered species within the genus were not conserved ex-situ and that there was limited knowledge regarding their cultivation, particularly from seed.

We were able to bring cutting material of Spatalla incurva into cultivation here in 2017. During 2020 a plant grown from this material flowered profusely.

Spatalla confusa A second member of the genus Spatalla to flower for us during 2020 was Spatalla confusa. Whereas Spatalla incurva is an upright growing small , Spatalla confusa is a sprawling subshrub that shows a significant amount of diversity of form across its range. Both species of Spatalla that flowered during 2020 were of interest to bumble bee species.

A pot grown plant of Spatalla confusa

Paranomus dregei We first encountered the scented sceptre in 2015 on the road to Die Hel in the Swartberg mountains and were delighted to find that the flowers smelt heavily of almonds. It is known from as far west as the Little Karoo and is another species that shows distinct morphological variability across its range.

In 2017 we collected material identified as this species from Camferskloof, near George in the Southern Cape. A plant from this material flowered at our nursery in 2020. Neither this plant nor those seen in Camferskloof were scented. Also, the leaves of this population are far narrower than those from Swartberg.

Weather 2020 Nursery Site The weather station at the Nursery Site only worked from May in 2020 as it had a malfunction before that point. Minimum temperatures were noted using a min/max thermometer while the weather station did not work. The data can be summarised as follows:

• Minimum annual temperature was -2.2C on March 6th and a temperature lower than 0C was recorded on 12 days. Most of these were March-May, with the last frost on 14th May being -0.6C. • Maximum annual temperature was 35.3C on 25th June. There were 26 days where the maximum temperature was over 25C and only 4 days where the maximum temperature was over 30C. • Actual frost dates and data: o -1.5C on 2nd March o -1.4C on 5th March o -2.2C on 6th March o -1.5C on 22nd March o -0.7C on 24th March o -1.7C on 28th March o -1.4C on 14th April o -0.8 on 12th May o -0.6C on 14th May

A staggering 1227.3mm of rain fell between 8th May and 31st December 2020. The wettest month was October at 238.8mm and the driest was May at 9mm. Interestingly June, July and August each received over 125mm, which amounts to quite a wet summer. The wettest day was 27th October, with 74.4mm rain. There were 2 days where over 70mm fell on that day. May was typically dry with only 9 mm rain and September was remarkably dry with only 67.8mm rain.

Protea grandiceps flowered well in Llanberis despite the high rainfall Daily Min/Max Temperature (°C) at Nursery Site 40 35 30 25 20 15 10 5 0

-5

02-Jul 09-Jul 16-Jul 23-Jul 30-Jul

04-Jun 11-Jun 18-Jun 25-Jun

01-Oct 08-Oct 15-Oct 22-Oct 29-Oct

03-Sep 10-Sep 17-Sep 24-Sep

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03-Dec 10-Dec 17-Dec 24-Dec 31-Dec

06-Aug 13-Aug 20-Aug 27-Aug

05-Nov 12-Nov 19-Nov 26-Nov

28-May 14-May 21-May < May Jun Jul Aug Sep Oct Nov Dec 0 8/ 0 5/ 2 0 2 0

Max of Outdoor Temperature(°C) Min of Outdoor Temperature(°C)

Nursery Site Daily Rainfall(mm) 2020 80

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40

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0

Monthly Rainfall(mm) at Nursery Site 400

350

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50

0 May June July August September October November December

May 9 June 125.4 July 348 August 157.2 September 67.8 October 238.8 November 122.4 December 158.7

Llanberis Garden The weather station in the Llanberis garden worked well in 2020 and can be summarised as follows:

• Minimum annual temperature was -0.3C on January 19th and a temperature lower than 0C was only recorded on this one day. • Maximum annual temperature was 33.5C on 25th June. There were 21 days where the maximum temperature was over 25C and only 2 days where the maximum temperature was over 30C. • A staggering 3984.3mm of rain fell over the year. The wettest month was February at 590.1mm and the driest was April at 61.2mm. Interestingly June, July and August each received over 300mm, which amounts to quite a wet summer. Spring, however, was typically dry with March, April and May receiving about 80mm each. The wettest day was 9th February, with 130.8mm rain. There were 6 days where over 100mm fell on that day. On February 8th and 9th 251.7mm fell in 48 hours. Dry periods include 19th March – 27th April during which time only 24mm rain fell altogether. 1st-21st May was also dry with only 21.6mm rain falling. No rain then fell between 23rd May and 2nd June.

Min/Max Temperature (°C) in Llanberis Garden in 2020 35

30

25

20

15

10

5

0

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09-Jul 19-Jul 29-Jul

10-Jan 20-Jan 30-Jan

09-Jun 19-Jun 29-Jun

04-Oct 14-Oct 24-Oct

10-Apr 20-Apr 30-Apr

09-Feb 19-Feb 29-Feb 04-Sep 14-Sep 24-Sep

(blank)

03-Dec 13-Dec 23-Dec

15-Aug 25-Aug

03-Nov 13-Nov 23-Nov

10-Mar 20-Mar 30-Mar

10-May 20-May 30-May

Max of Outdoor Temperature(°C) Min of Outdoor Temperature(°C) •

Llanberis Daily Rainfall(mm) 2020 140

120

100

80

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20

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Llanberis Monthly Rainfall(mm) 2020 700

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January 390.9 February 590.1 March 109.2 April 61.2 May 74.7 June 309.3 July 340.8 August 417.6 September 226.5 October 560.7 November 540.3 December 363

Notes: The easyweather software is not adding up the rainfall correctly for days, weeks and months. I have assumed that the hours is correct and summed up from that. I fundamentally do not trust the rainfall measurements from this weather station.

Impact Our ‘proteas With Altitude’ project is having a positive impact for protea cultivation and conservation across the wider botanic gardens network. The cultivation protocols and resources we have been producing are starting to be used in other collections. The temperate Proteaceae propagation at the Royal Botanic Gardens, Kew, is now using the ‘FossilPlants 2’ compost mix we developed with Melcourt Ltd. The team at Kew are also starting to use terracotta-coloured pots rather than black to reduce temperature at the root zone for protea seedlings. St Andrews Botanic Garden is looking to start using the same compost mix for many of its Ericaceous and low nutrient species. Hortus Botanicus, Amsterdam and Bergen Botanic Gardens are also now looking to create similar composts to ‘FossilPlants 2’ for their Ericaceous and Fynbos plant species.

2020 saw an article, written by us, regarding our 2017 South African Proteaceae ex-situ gap analysis printed in BGCI’s BG Journal. This article has had a positive response from across the botanic gardens network. Similar gap analyses are being undertaken to prioritise species of conservation concern and to guide wild collections for ex-situ conservation by the newly formed BGCI led Global Conservation Consortia. During 2021 we will be undertaking one for the genus Erica using similar principles to that of our 2017 analysis.

One of the most significant things that happened for Proteaceae conservation during 2020 was that the IUCN Red List of threatened species uploaded assessments for 80% of worlds Proteaceae taxa. Across our collection we care for 35 species of Proteaceae now assessed globally as threatened (Vulnerable, Endangered or Critically Endangered) and a further 21 species globally assessed as Near Threatened. A full understanding of the cultivation of these species may, in the future, be integral to creating options for their conservation and, as such, this global red listing highlights the importance of our project.

Aims for 2021 Further improvements to irrigation at the nursery are planned for 2021 with the addition of a 3000l/hr, 3.5 bar pressure, pump to help move rainwater around the nursery site. After 6 years of daily wear and tear new ‘Mypex’ weed proof membrane is required on those areas of the nursery that get the highest level of footfall.

A new, large, protea trial bed had been planned for creation during 2020 but was impacted by the COVID-19 pandemic. Creation of this is now planned for 2021 and initial work on this was undertaken during the latter part of 2020. We hope that this bed will be finished and planted by early summer 2021.

Budget During the period 1st January 2020 to 31st December 2020 Outgoings Rent £550 Electricity £150 Sundries £110.54 Total Expenditure £810.54 Income Donations £0.00 Plant sales £214 Total income £214

Personal investment £596.79

Thanks The whole project would not have been possible without the help of the 64 backers of our 2016 crowdfunding project, the Stanley Smith (UK) Horticultural Trust and a generous private donation.

Special thanks to Martin Smit (Hortus Botanicus, Amsterdam), Cherise Viljoen (Kirstenbosch), Rupert Koopman (The Botanical Society of South Africa), Robbie and Vicki Thomas, Kevin and Kathy Collins ( Farm), Bob Stevens, Rosie Kressman and Natalie Chivers (Treborth Botanic Garden), Ondine Schrick (Silverhill Seeds), Cape Nature, BGCI, MSBP, Outramps CREW and identifiers on the INaturalist website. Additionally, we would like to thank The RHS, The Yorkshire Arboretum, The Eden Project, The Scottish Rock Garden Club and the horticultural teams at The Royal Botanic Gardens, Kew, Edinburgh and Logan.