When only the best will do | Van Arnhem Nursery

Situated at Godalming near Guildford, Van Arnhem Nursery supplies a vast array of the highest quality trees, shrubs and perennials to professional horticulturalists, garden designers, high-end builders and landscapers.  Situated in an affluent area, it has a discerning customer base.

“Our customers are looking for plants that are near perfect – garden centre quality,” says General Manager, Jamie Bullard.  “To satisfy demand, we grow smaller numbers of a vast array of species.”

Three years ago, Van Arnhem switched to Levington Advance and now relies on two bespoke sustainable peat-reduced mixes delivered as probales.  Both the coarse CNS and herbaceous mixes contain Fibagro Advance Standard – ICL’s own woodfibre product manufactured from home-grown FSC sourced wood – which is gradually being increased.

The herbaceous mix contains Osmocote Exact High K (8-9 month) which works well across the perennials range, helping to control growth and keep plants relatively compact.

“In the past faster growing species, like Nepeta and Salvias, had to be trimmed to keep them saleable,” says Jamie. “Since switching to Osmocote Exact High K we haven’t needed to do this – cutting down on labour. We’re also seeing a reduction in losses over winter – less soft growth over the colder months equals less wastage.”

Any supplementary feed needs are met using Universol Blue (18-11-18+2.5MgO+TE) during the growing season, and Universol Violet (10-10-30+3.3MgO+TE) late season to toughen up growth.

The nursery recently switched its Levington Advance CNS mix from Osmocote Hi-End (8-9 month) to Osmocote 5.

“With its enhanced S-shaped nutrient release curve, new trace element system and higher N content – our new Osmocote 5 helps overcome the challenges of higher pH and lower nutrient buffering that can occur with peat-reduced and peat-free growing media,” says ICL technical area sales manager Steve Chapman. “Building on the success of Osmocote Exact Hi-End, it has been developed specifically for use in sustainable Levington Advance mixes.”

Peat-free trials extended this year

“We haven’t had many enquiries for peat-free plants, however it’s important to be ready for the peat ban,” says Jamie.  “In the past, we did a peat-free trial but it wasn’t a success.

“Now we’re taking small steps trialling Levington Advance Sustain – it’s going very well.  “We find these mixes flow better through our potting machine, compared to the 100% peat mixes of the past – which helps speed up the potting process.”

We started in 2021 in our tree production and, to be honest, didn’t notice much difference; this year we’ve included some perennials.  Containing coir, Fibagro Advance standard and 0-8mm pine bark, it’s an open, free draining mix and we’re getting good results.  Within a week of potting Lavenders into 1L pots they’d rooted really well.”

Scheduling vine weevil IPM programme

Like many nurseries, Van Arnhem has relied on a succession of chemical vine weevil controls – most recently thiacloprid (withdrawn 2021).  “Incorporated into our mixes, the pest wasn’t a problem, even though the nursery backs on to woodland,” says Jamie.

With input from Steve, the team now follows a scheduled IPM vine weevil control programme and began applying nematodes in autumn 2021. This spring, once growing media temperatures exceeded 5°C, Jamie applied the cold tolerant Vine Weevil Seeka CT (containing the beneficial nematode Steinernema kraussei) to susceptible crops, such as Primulas and Euonymus, as well as high value crops.

“We’ll repeat this late autumn to mop up any larvae before temperatures dip below 5°C,” he says. “In May, once growing media temperatures rise above 12°C, we blanket treat the whole nursery with Vine Weevil Seeka (Heterorhabditis bacteriophora) – and repeat in early autumn. So far so good, we haven’t noticed any increase in pest pressure.”

Applied via the overhead irrigation system and drippers, the packs are emptied into the irrigation tank along with Transporter. Optimising water distribution in the growing media, the Transporter promotes a more even spread and penetration of nematodes in growing media.  The pump helps keep the nematodes well mixed, as it takes approximately 1-2 hours to apply across the nursery.

“The Transporter creates foam, so you can see when the nematodes arrive in the irrigation water,” says Jamie.

“The adult beetles indiscriminately lay eggs on the surface of pots they cross on their way to reach their favourite species. We’ve started using Pitcher GR across the site. Quick to apply, it targets eggs and young larvae.”

“The future of vine weevil control is likely to include more biologically friendly alternatives, which generally require more planning regarding their application to maximise performance,” says Steve.  “Even when applied correctly, biological products tend to have slightly lower levels of control compared to a chemical alternative. Going forward there needs to be an understanding of the acceptable levels for this pest and what the threshold is before significant damage occurs.”

Biostimulant trials

Jamie carries out any conventional spraying early evening, when the nursery is closed. “I’d prefer not to spray and, being a busy nursery, exclusion zones are inconvenient,” he says. “With the loss of certain key chemical actives it is becoming increasingly challenging to control diseases such as rusts on Heucheras.”

The nursery is about to trial ICL’s biostimulants – Vitalnova Prime and Vitalnova Guardian – products to help improve overall plant health.

“We’ll be working closely with Steve,” says Jamie.  “He visits regularly and is always at the end of the phone to offer advice or reassurance – together we work things out.  I feel I get good, honest advice. Coming from a growing background, he genuinely understands the issues I’m facing and the service is good.”