Research and analysis

Tree Supply Report

Analysis of tree sapling supply in Great Britain 2022/2023.

Documents

Tree supply report - data analysis and appendix

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Details

Summary

The information in this document was gathered through informal interviews and visits to 15 forest nurseries. The nurseries’ views presented here have been compiled by the Forestry Commission into the present report.

Overall, forest nurseries regard the past few seasons as very positive. Despite some weather-related issues and difficulty sourcing labour, their sales have generally been going up for a few years, thanks to the increased interest in tree planting. Nurseries are at the same time conscious that this current interest is no guarantee of high plant demand in the medium and long term. For this reason, most of their recent investments have been towards enhanced sustainability and efficiency, and expansion has been moderate.

The most pressing issues all nurseries are facing are:

  1. seed procurement
  2. shortage of labour
  3. uncertainty about demand
  4. difficulty sourcing seed from the required provenances

Increasing the share of forward-contracting (contract-growing) could be a way of addressing some of the points above.

Work on estimating demand is underway but proving to be challenging, especially for assessing restock numbers across Great Britain (GB).

Seed

Nurseries had no hesitation in naming seed procurement as their major risk. The issues facing seed are multiple and are detailed below.

Seed sources

Despite the Forest Reproductive Materials (FRM) Register of Basic Material currently listing 467 seed sources in GB, many of these stands are not in use and/or difficult to access. There is a clear need to increase the quality (=ease of access to seed crop), number, and variety (both in species and provenance zones) of seed sources available, if we want to ensure a resilient and genetically diverse seed supply.

Cyclical variations in seed production (i.e., mast years) are a natural phenomenon. A mitigation measure for this is to collect large amounts of seed in bumper years, and then storing it; however this is not always possible. Some species (oak, sweet chestnut, sycamore etc.) cannot be stored for more than a few months without critical loss of quality. This can lead to fluctuations in the market for the above species.

When seed crop is available and accessible, there are sometimes difficulties in sourcing the manpower to collect it. Professional seed collectors are often self-employed, and because of the seasonal nature of the job, it is not a profession which appeals to many.

Seed market

There is only one substantial private seed trader for forest seeds in GB. It is perceived that this creates a risk both in economic terms as well as for the sector’s resilience. Multiple nurseries already have reported not being able to source all the GB seed they had planned for in the past season.

Other ways to source seed available to nurseries are:

  • public sector (currently limited to Sitka spruce, Scots pine, and Lodgepole pine)
  • importing seed
  • collecting their own seed (usually contracting professional seed collectors)

The nursery sector recognises its dependability on seed procurement, and many nurseries have either started or increased their own seed collections in an effort to reduce their seed supply risks. Because the number of professional seed collectors is limited, however, even this route is not always viable; and only a few nurseries currently have seed processing capabilities. For the other nurseries, seed processing would still have to be outsourced.

Imports

A few nurseries have reported difficulties in sourcing seed from the EU in the last couple of seasons, both in terms of responsiveness, availability, and quality. With the EU having set their own ambitious planting targets, it is not surprising that the GB is struggling to import seed. While imports are overall a low percentage of the total seed circulating in GB (only 2% (in weight) of the seed registered with FRM 01/11/2021-30/10/2022 was imported, data not published), some species heavily rely on imports.

Public sector

Nurseries have shown a strong appetite for Forestry England to take on a more meaningful role in seed supply, especially as a way of de-risking the current reliance on a single UK supplier. Nurseries would particularly like to see Forestry England provide a large quantity and variety of broadleaf seed, as was the case a few decades ago. The new seed extractory at Delamere nursery will have capacity to process additional broadleaf seed, however this will only be sold to nurseries if they have been unable to procure it elsewhere. This clause was added to minimise interference in the private market, but does not apply to the species currently already supplied.

Labour

Shortage of labour has been an issue for a few years, and has been felt even more dramatically since the EU exit. Almost all nurseries rely on agency workers throughout the busy season (winter), particularly for grading trees before dispatch. Grading has repeatedly been reported to be the primary bottleneck in the nursery industry, both in bareroot and in container production.

Automation

Problems with labour availability have been the main driver behind the push for automation. Some nurseries have invested to partially automate grading, transplanting, and have even switched to different methods of growing. There is an understanding in the sector that the issues with labour are not temporary, and it would be unsustainable in the long-term to keep relying on manual labour where tasks can be automated. This does of course require considerable investments. It should be noted that, since forest nurseries are a niche industry, new machinery is almost always made to order rather than off-the-shelf. This brings its own issues of higher costs, longer lead times, prototype functionality etc. Bareroot nurseries are by design considerably more difficult to automate compared to container nurseries.

Skilled workers

Skilled workers have been identified by some as another area where the sector falls short. Being a small industry, it is difficult to find experienced growers with specific forest nursery knowledge. Horticulture growers have transferable experience and knowledge, but do not seem to be attracted by the forest nursery sector, or perhaps are not aware of it.

The issue of attracting younger skilled workers into the sector is perceived differently across the nurseries. Some felt that the growing interest in green jobs has brought some valuable young people to the sector, while others thought that it gave people the wrong expectations (i.e., an almost bucolic job). Likewise, some businesses have expressed some concern at this knowledge/generational gap, while others are confident in their succession planning.

Climate change and earlier planting

Lifting (harvesting) in bareroot nurseries is done while saplings are dormant. This is roughly between November and February, but is highly dependant on weather. Wetter, warmer winters such as we have seen in recent years, reduce the lifting window, further exacerbating the labour issue.

Climate change challenges do not stop at the nurseries, either. Foresters are now also under pressure to plant before Christmas, to give trees a better chance to survive what are increasingly looking like drier springs and summers. Newly planted trees are more susceptible to drought, while earlier planting can allow the saplings to establish a good root system before the outset of the dry season. This shift in the forest planting season does of course weigh back onto the nurseries, which are under even greater pressure to lift and dispatch trees in an even narrower window. Because trees are also (generally) entering dormancy later in the year due to global warming, this can lead to lifting and planting of bareroot trees which are not fully dormant (i.e., their metabolism is still active), and therefore have lower survival rates.

Container growers do not have the same constraints, because the soil plug around the tree allows for lifting and dispatching outside of the tree dormancy period.

Provenance

The seed provenance debate is not new to anyone in UK forestry. Nurseries appreciate that to plant “the right tree in the right place” provenance often needs to be taken into account. There is an overall concern however that provenance choices are not always understood by tree planters, and that can leave nurseries and seed suppliers with the burden of trying to source and supply a large number of provenances for all eventualities. Additionally, nurseries are at times requested species from provenances where they do not occur, or where seed is unavailable. This flags up an underlying lack of knowledge about seed provenance role in forestry and woodland creation, which nurseries think should be addressed.

While provenance was highlighted by almost all nurseries as being a concern, it doesn’t seem to lead to significant sale losses. Customers usually eventually accept trees from another neighbouring provenance, or approach other nurseries until they find what they are looking for. Despite this, nurseries say significant resources are spent on sourcing and growing multiple provenances, which for traceability reasons need to be kept in separate batches from seed to sale.

Forestry Commission’s guidance does not emphasise the need for specific provenance, focusing on genetic resilience instead.

Planting targets and grants

Nurseries have expressed their frustration at planting targets repeatedly not being fulfilled, and argue that overambitious targets confuse the market rather than boost it. Nurseries will not significantly increase their production over a promise, because the risk of unsold stock is too high. With very few exceptions, it is not possible to carry-over unsold trees to the following season without an unacceptable loss in quality. Overall, nurseries still have reasonable capacity to expand their production, and will do so as the market grows.

Knowledge of the upcoming volume of trees needed for planting (and ideally species) would be very valuable to nurseries, but this needs to be based on concrete figures rather than abstract targets.

A few nurseries have also expressed the wish to be consulted/involved in the design of the next planting grants, to ensure that grants are as efficient as possible with regards to tree supply. The two-year planting option with England Woodland Creation Offer (EWCO) grants is generally seen positively, but there needs to be more consideration of the supply chain.

Sustainability

Whether of their own choice or pressured by externalities, nurseries are making many changes towards sustainability.

Peat reduction / elimination

While the issue is still under consultation, the sector expects that the sale of peat for professional users will be banned in the near future.

Most nurseries that produce cell-grown stock have yet to switch to 100% peat-free growing media, with a peat-reduced mix being the most common medium used in containers, pots and miniplugs. The majority of nurseries are fairly confident that they have found a sufficiently good peat-free mix, but there is still some concern that completely removing peat from the growing media will negatively affect quality of the trees. This will be particularly true for miniplugs and smaller containers, where peat’s excellent water retention is key to keep the roots at a consistent moisture level.

Agrochemicals

The ban on plant protection products (PPP, or pesticides) is felt throughout the whole arable/horticultural industry. Chemicals are being withdrawn from sale due to both more stringent safety/environmental regulations, as well as for economic reasons. PPPs must regularly go through a long and expensive regulation process in order to be sold in GB, and the manufacturing companies often drop the least profitable products.

An example of the latter is quinoclamine (brand name Mogeton), which use was banned from July 2021, and which was the only known effective product on moss and liverwort. Liverwort especially is a very persistent weed in container-grown trees.

Nurseries used to have a large armoury of PPPs which is now shrinking, forcing them to consider alternatives. Herbicides are where the losses are felt more strongly, especially in bareroot nurseries. While in some cases there is the option of mechanical weeding, hand-weeding is often the only alternative when trees are very young. Research into automated weeding (e.g., laser) is in its early stages and not likely to reach the market as a viable alternative in the near future.

Another key product widely applied by most bareroot nurseries was the soil fumigant dazomet (brand name Basamid), used to eliminate soil pathogens as well as to deplete the weeds seed bank. The product cannot be used as of 2020 due to concerns for the environment and operators’ health. Tree nurseries were especially concerned about the impacts of withdrawal of this chemical. Some nurseries have decided to invest in soil steamers as an alternative, while others consider their diesel usage too wasteful and expensive, and are now relying on best practice only.

Soil health

Soil health is an issue strongly felt by all bareroot nurseries; the quality of their trees strongly relies on it. These nurseries face the issue of soil compaction caused by tractors driving on the soil in winter (when it’s most susceptible to damage) to harvest trees. Additionally, the intensive farming techniques used to grow saplings often deplete the soil of many nutrients and organic matter.

Most nurseries use crop rotation to improve soil structure, increase organic matter content, and also tackle weeds. Some are looking at more sustainable ways of growing and harvesting trees.

Species shortages

When asked about species in high demand but low supply this year, most nurseries mentioned the small-leaved lime (Tilia cordata), which appears to be one of the most popular replacements for ash. Of the coniferous species, Pacific silver fir (Abies amabilis) and the redwoods (Sequoiadendron giganteum, Sequoia sempervirens, and Metasequoia glyptostroboides) are among the most requested species that are not always available. The low availability is due to either scarce seed or difficulty in growing the crops (redwoods are particularly sensitive to fungal infection).

Despite the shortage of acorns in 2021, nurseries have planned their production to avoid a large gap in the market for oak.

The Data analysis and complete species dataset used for analysis can be found in the Appendix (available as a separate document on this page).

Published 1 March 2023