How many allotments does Cambridge need?

I have been asked how many new allotments Cambridge needs in the foreseeable future. This post is an attempt to answer that question, using data from my updated survey of current usage and demand together with the draft Greater Cambridge Local Plan (GCLP) which proposes new housing developments through to 2041 and beyond.


I calculate that 0.84 hectares of new provision are needed per 1000 residents in the proposed housing developments on the edge of Cambridge. This would meet demand from existing waiting lists plus likely demand from the new residents. There’s not much space available elsewhere, except North East Cambridge where the council does not intend to provide allotments. 0.84 ha/1000 is double Cambridge City Council’s current open space standard for allotment provision.

Caveats and assumptions

This is a conservative target. While I believe that the popularity of allotment gardening is likely to grow, and moreover that future food crises and recessions will force much greater demand (as did the wars and oil shocks of the 20th century), we cannot assume this. Therefore I have based this target on figures from my recent survey, which evidences current usage and demand.

My survey is limited to allotments in Cambridge city, and so my recommended target is for the enlarged Cambridge city envisaged in the GCLP.

Other than the rural sites, the “First Proposals” draft plan (November 2021) features three categories (“Broad locations”) of residential development: Cambridge urban area, Edge of Cambridge and New settlements. The enlarged Cambridge city comprises the existing city together with the Cambridge urban area and Edge of Cambridge sites.

Greater Cambridge Local Plan “First Proposals” site allocations

The Cambridge urban area sites are mostly already developed. I have not looked in detail at all of these but I assume that these Cambridge urban area sites will not include any significant new allotment provision. Therefore I propose a pro-rata target for the expected populations of the Edge of Cambridge sites, which will meet overall demand from the whole of the enlarged Cambridge city.

The “First Proposals” give numbers of new homes but not the corresponding new population. I have assumed that there will be 2.2 residents per home. Please tell me if that is wrong or where I can find authoritative expected population figures. (Surely they should be made explicit in the plan.)

“First Proposals” Housing delivery, and derived new populations

How many allotments are needed?

As discussed in my survey, we cannot meaningfully count allotment “plots” due to variations in size and record systems. The correct question for planning purposes is:

What area of allotments is needed?

Below we calculate:

  • the total population to serve
  • a realistic estimate of the current waiting list
  • demand from current residents
  • additional demand from new residents (assumed to be at the same rate)
  • and finally an area of new provision to meet the total of current and additional demand

Population of enlarged Cambridge

The “First Proposals” imply that the total population of the enlarged Cambridge post-2041 will be 203867. 62% of the new population will be in the Edge of Cambridge sites.

Total population of enlarged Cambridge, if the “First Proposals” housing targets are implemented.

Current waiting list estimate

As discussed in my commentary on the survey, Cambridge’s allotment Waiting List (WL) is impossible to calculate with certainty. The apparent total of 1118 is inevitably inflated by “weediness” and double-counting.

For this estimate, I assume that “weediness” is 30% in the council’s WL (the upper end of the officer’s estimate) and 20% for the non-council WLs (based solely on my experience of letting plots at one site, over 20 years). We know that there is no double-counting within the council WL; I simply guess that double-counting amongst the 467 names on non-Council WLs amounts to 200.

Together these assumptions yield an estimated Adjusted Current Waiting List (ACWL) of 669 individuals actually waiting for an allotment in Cambridge City, as of November 2021.

An estimate of the actual waiting list, based on Nov 2021 data with adjustments for “weediness” and double-counting

Current and future demand

Current demand for allotments in Cambridge is 2880. This is the number of tenants (2211, from the survey) plus the waiting list (ACWL = 669 above). I ignore demand from tenants who want additional land, in order to produce a conservative target.

Assuming that future demand will be the same, pro rata, amongst new residents as amongst current residents, yields this projection for demand in the enlarged Cambridge:

Current demand, and projected future demand assuming the same demand pro rata amongst new residents

Current usage

Essentially all Cambridge’s allotment sites are full, though inevitably a few plots are vacant whenever managers report, where previous tenants have left and the next tenancies have not commenced. In November 2021 vacant plots amounted to 16.3 of a total 1480.8 (10-pole equivalents) so usage of the current provision is 98.90%.

New provision required

I think we should aim to meet demand by providing new allotments at the current overall tenant density of 51.6/ha. It could be argued that target density should be higher, matching the council-managed sites (89.0/ha.) where plots are small and there are often no shared facilities. It could also be argued that target density should be lower, matching the society-managed sites (43.9/ha.) which provide a variety of plot sizes and have shared facilities.

The calculation below includes the current rate of usage, rather than the total current provision.

The enlarged Cambridge city should have 28.8 ha of new allotments.

New provision required in the enlarged Cambridge city, providing for both current and new demand, at current density

Where should new allotments be provided?

Ideally, allotments should be near to the populations that will use them. This should be feasible in the Edge of Cambridge sites. I am assuming that there will be no significant new provision in the Cambridge urban area or existing city due to the lack of open space. With that assumption, all new provision for Cambridge will need to be in the Edge of Cambridge sites.

This requires changes to the Open Space standard for allotments (Appendix I). Firstly, allotments should be provided at 0.84 ha/1000 residents in these Edge of Cambridge sites. This is more than double the current standard of 0.4 ha/1000 (Table I.1). Secondly, where “it would be difficult to achieve full provision” (para. I.9), that full provision must be provided somewhere else. This is why I suggest specifying the provision required in the Edge of Cambridge. Monies “paid towards the enhancement of existing allotment sites” (para. I.9) are no substitute for growing space.

New provision required pro rata in Edge of Cambridge sites

Is there space for allotments in North East Cambridge?

NEC is one of the Cambridge urban area sites and I have assumed above that there will be no new allotment provision. Of course, there is space for new provision on this huge 186.5 ha site. The area east of Milton Road contains significant undeveloped open space which could provide allotments. By the current open space standard of 0.4 ha/1000, with a housing target of 8350 accommodating 18370 new residents, 7.35 ha of allotments should be included.

This council topic paper, part of the “First Proposals”, says that NEC “generates a need for 6.5 hectares of allotment/community gardens space.” Note the change of language from the previous council discussion paper which said that 6.5 ha of allotments should be provided for 16236 residents in NEC and “It is unlikely that there will be sufficient space to provide all of this space on-site. Off-site provision should therefore be considered to provide this.” and stated more bluntly that the on-site allotment provision will be “in the form of community garden/sheds/orchards”.

However, the same topic paper goes on to say:

Allotments/Community Gardens

Given the unique high-density nature of NEC and the amount of allotment provision required by the adopted policy, it is not envisaged allotments can be provided on-site in a traditional format. On-site community gardens, communal shed spaces and integrated areas supporting local food production will also be an acceptable format. A balance will need to be found that maximises the benefits to the local community and environment.

PLANNING POLICY – JUNE 2020 Appendix C5: Open Space Topic Paper

The topic paper includes some utterly fanciful proposals for non-traditional format growing spaces (paras. 34-43). I will write about those another time, but council thinking about this site is clear: they do not intend to provide any allotments at NEC.

Other growing facilities such as community gardens and orchards will be a welcome feature, but they are not an adequate substitute for allotments. We already have an example illustrating this. At Clay Farm, the 0.4 ha/1000 allotment provision was reduced by 25% and substituted by a community garden. The allotments, which finally opened in May 2021, are already in full use with a waiting list. Demand will continue to grow at least until the housing is completed.

Comments and conclusions

There will be particular impacts on some existing allotment sites. We have already felt this keenly at Foster Road in Trumpington where large new housing estates led to a large increase in demand. The huge North East Cambridge (NEC) development will create extra demand at the adjacent Nuffield Road site, and probably at Kendal Way and Milton as well, unless it includes adequate provision. Moreover, new provision must be delivered early so that plots are offered when the new residents arrive (not seven years later as in the southern fringe).

The New settlements sites should also have new provision. Cambridge City’s current Open Space standard of 0.4 ha/1000 residents would be a good starting point, together with additional crisis capacity.

Broader policy

Allotment provision would ideally be set within the context of a comprehensive food strategy for Greater Cambridge. This should address production, supply chains, storage, quality, distribution, retail, markets, cooking, hospitality and, as we have recently been reminded, food poverty and emergencies. The CSF plan addresses some of this. However, an overall strategy is lacking.

Current council documents recognise most of the benefits of residents growing food: physical and mental health, sustainable lifestyles, biodiversity, and community. This could be supported by a policy commitment:

Every resident should have the opportunity to grow their own food.

However, the homegrown contribution to food production – the original, statutory and primary purpose of allotments – is not mentioned in any council document that I have found. The creation of food growing spaces could be supported by another policy commitment:

Greater Cambridge will produce more of its own food.

It would be easier to convince planners to provide allotments, community gardens, a city farm and another COFARM in that context.

Additional capacity

Having made a conservative proposal for planned new provision in the enlarged Cambridge City, I think we should also have an eye on a possible (some would say inevitable) future in which some food supply chains fail. More local growing space would be essential, and quickly. Hungry people don’t wait around. So it would be prudent to ensure that we have sufficient open space with the potential to meet crisis demand, ideally without digging up wildlife habitats, sports pitches and so on. To quantify demand driven by food shortages, consider the level of allotment provision at the end of WWII.

Rural provision

I don’t know much about levels of provision in the villages. Rural provision is rather different in that is often possible to meet demand by renting or purchasing a piece of agricultural land. So I will not say anything about planning provision in the Rest of the rural area or Rural Southern Cluster sites, except to suggest that Greater Cambridge planning should seek evidence of current usage and demand, and use that to inform the GCLP, because planned provision is better than ad hoc provision. For example, Waterbeach allotmenteers currently face losing access to their privately owned allotment site, because Network Rail wants to close the level crossing.

Data sources and calculations

Data used above are from my November 2021 survey of current usage and demand together with the draft Greater Cambridge Local Plan also from November 2021.

Here are my calculations using these data.

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