Weighing up the factors
Before we started growing we had some ideas of what crops we’d like to grow, but we soon realised that for a more thorough crop plan we needed to weigh up lots of factors:
- Soil – soil is a complex area. Easy conclusions about what crops are suitable for certain soils are difficult to make, as there are so many other factors to consider. Our starting point was a soil analysis, which we did immediately after the land was bought, and this gave us an idea of the balance between clay, sand and silt in the soil, as well as pH (which is easily altered) and nutrient and mineral levels (in general, less quick or easy to alter organically). Of our two fields we thought the first would grow just about anything because it was closer to a loam (a good balance of clay, sand and silt) with a crumbly structure that drained more easily, whereas the second field was more heavy and we were less sure about. We thought we’d struggle with root crops on it. We found it useful to look around at neighbouring land to see what was growing there (grass and cereals mainly, but some swedes being grown nearby) and from speaking to neighbours we were able to get a rough history of what had previously been grown on our fields (again, mainly cereals, but some potatoes and going further back in time lots of celery too). These were really useful pointers. Finally, the type and amount of available fertility is another soil consideration. We always knew that we wanted to grow our vegetables ‘stockfree’ – i.e. without using animal manures. Although it’s possible to grow any vegetable this way, we thought we’d leave the heavy feeding vegetables like potatoes and squash to other local growers that were happy and able to add lots of cow muck to their soil
- Site (size, aspect etc) – growing on a north-facing slope or at a high altitude is obviously going to limit what you can grow. Similarly, the amount of land you have available. Our level site is great for vegetable growing, although its open aspect means it gets very windy (not good for certain crops, e.g. broad beans). 21 acres seems like a decent size to try most crops on a field-scale – i.e. fairly mechanised with tractors doing most of the work, as opposed to a small market garden size plot (e.g. under 5 acres) where most jobs would be manual or with pedestrian operated machinery. This did push us away from crops like salad leaves or herbs, which generally suit smaller more manual growing sites. However, we thought that we would find it harder to compete with bigger scale growers of, say, potatoes and onions as for these crops 21 acres is a drop in the ocean
- Climate – as well as looking at regional trends (e.g. wet in the North West), it’s the more local micro-climate that really matters (annual rainfall, timings of first and last frosts). Speaking to older farmers in the area is a great way to find out about local variation. In our case, the wet climate and fewer hours of sunlight made us nervous about growing onions and sweetcorn, but otherwise we were happy to try most other crops
- Pests – can be a major factor in choosing crops. When we spoke to neighbours we were pleased to hear that there weren’t any rabbits in the area (we have hares instead), but warned of the potential problem of pigeons. We put mesh over all our brassicas and use electric fencing to keep hares off our crops over winter (all adding to costs) but, so far anyway, our losses due to pest damage are nowhere near what they could be if we had a local rabbit population. Insect pests need considering too perhaps most notably with the spread of leek moth recently. Growing at altitude can be an advantage with, for example, significantly less root fly issues
- Equipment and infrastructure – if we had taken on a site with polytunnels then our crop plan would have been radically different (i.e. open to a great range of highly sought-after tunnel crops like salads, tomatoes, peppers as well as various season-extending options). We’re in a green belt so planning permission for tunnels would not be easy. As it was, our bare site lends itself to mechanised field-scale growing – however, this obviously requires equipment, and some crops need more equipment than others. So there was a question of budget too. At one end of the spectrum might be cabbages, which need a module planter (cost anywhere between £500 – £5k), but could get away with a very simple cheap tined cultivator for weeding (e.g. £200-£300), and harvesting is done by hand. At the other end of the spectrum might be carrots which are relatively cheap to sow (e.g. £200 for seed drill) but more expensive to weed (flame weeder and ‘stretcher-bed’ weeder, £1k+) and expensive to harvest (root lifter, £1k+). Our budget definitely encouraged us towards hand-harvested crops, and simpler weeding implements
- Supply & demand – this is probably the biggest factor, with obvious considerations: don’t grow crops that are already fully supplied and don’t grow crops for which there’s no demand. Again, it’s all about the detail. Coming from a retail background was a definite advantage. We knew where the demand was and where the gaps in supply were, and we could quantify both. Spinach, garlic, celery, spring onions and radish were the field-scale crops that came to mind immediately, as well as over-wintering greens like leeks and savoy cabbages. This remains the core of our crop plan
- Risk – we’ve only considered this factor more recently, looking at how some crops are inherently more risky than others. For example, long over-wintering crops like sprouting broccoli carry the risk of being wiped out by a harsh winter. Pest-prone crops (e.g. carrots) are also more risky. We’ve come to think that it’s a good idea to try and spread these risks across a range of crops – a wide enough range to cope with one or two crop failures, but not too wide as to affect efficiency of production
- Profitability – presuming we have evidence from previous years’ growing (see below, costs of production and record keeping & analysis), the profitability of each crop will help us decide whether to grow more or less next year, or whether to stop growing a certain crop altogether. This must be weighed up very carefully with demand, however. If an unprofitable crop brings in customers (in our case, say, cabbages) who go on to buy plenty of other, more profitable, crops from us (e.g. celery, leeks) then it could still be worth growing. It depends on how your customers buy from you – do they need a minimum value in each order to make it viable?
- Rotation – all the other factors were great at directing us towards certain crops but, practically, it all had to fit within a rotation. We’ve found, for example, that demand for brassicas outstrips the demand for other vegetable families. It’s a lot easier to deal with this on a bigger mixed farm where there’s plenty of land (and years in between growing the same family of vegetables) to grow whatever you want each year. It’s considerably harder to make a rotation fit on a site that’s devoted only to vegetables. We’re not yet at the levels of production where this is a major factor, but we know in future years that there’ll come a point where we’re not able to meet demand on certain crops as we don’t have enough space within our rotation
There are so many ways of designing a rotation and plenty of better, more experienced sources of advice on how to go about it (see list of books & resources in section 4). In any case it’s never set in stone (e.g. we’ve already moved from a seven year to a six year rotation). Generally though, our key guiding principles were firstly to grow the heaviest feeders early on in the rotation – i.e. as soon after the long-term fertility building ley as possible – and secondly to make sure soil is not left lying bare or idle. This is where we’re up to with our rotation:
Year 1 – clover ley (mix of red & white clover)
Year 2 – clover ley
Year 3 – brassica family. Follow early crops with crimson clover, undersow late crops with trefoil
Year 4 – beet family. Follow with vetch / ryegrass, and some straight into over-wintering garlic
Year 5 – allium family. Follow early crops with persian clover
Year 6 – umbellifer family + lettuce. Followed by clover ley wherever possible; if not rye cereal
Annual crop planning
In November of each year we start planning the next growing season (May through to the following April), and we aim to have the plan finalised and our seeds and modules ordered by the first week of January.
During this two month period we go through various steps, shown in the following flowchart and detailed further below. The process involves several spreadsheets – instead of showing fully filled-in spreadsheets, we have just shown the info for two crops, savoy cabbages and radish (one planted and one sown), in order to demonstrate the process a bit more easily.
(1) meet our customers
We sit down with each customer and talk through potential volumes for the following season, also asking if there are any new crops they want us to grow. Even if there’s not likely to be any change year on year, we really value being able to meet face-to-face with customers. It’s good for the trading relationship, gives a chance for both us and them to review the season just gone (quality, prices, reliability etc.) and look at the wider market (consumer trends, what other suppliers are doing etc.).
We fill in the following ‘customer volumes & value’ spreadsheet (LINK to attachment) based on what customers tell us. During the meeting we fill in the ‘overview’ page. Then we turn that into monthly volumes on the specific page for the customer. Once we put in a ‘likely price’ in column S of each customer page, the ‘value’ fields are automatically filled in, and everything is automatically collated in the final two summary pages.
It’s a really useful spreadsheet that not only tells us how many kg or pieces of each crop we need to be aiming for, month by month, but also gives a forecasted monthly income (therefore feeding into our cashflow forecasts – see section 2).
It’s at this stage that we rule out any crops that we haven’t got enough demand for. As an example, we offered fennel to our customers for the 2012-13 season, but there wasn’t enough demand, so we didn’t grow it. We don’t use any scientific method of working out the threshold of what’s a viable volume for each crop, it’s more of a collective gut feeling: do we want to be fiddling about in the field growing fennel for just 5kg a week demand? In this case the answer was no.
(2) work out maximum capacity and settle on final volumes
We then check that we haven’t offered more than we can deliver. This involves filling in another spreadsheet, ‘crop areas’ (LINK to attachment), which calculates the number of hectares needed to grow the required crop volume. If the combined hectarage of crops within one growing block adds up to more land than there is available, then we know we have to go back to our customers and revise our numbers.
We start by inputting the spacings between rows (inter-row) and in-the-row (intra-row). We actually use 19” (48cm) inter-row spacing for all our crops (see section 4), but they’re not evenly spaced within each tractor width. We purposely leave a wider gap between the outer two rows and the tractor wheels to allow for effective weeding. For this spreadsheet, then, we start with our tractor width (64” or 162.5cm) and divide by the number of rows in each tractor width (3) to get 54.2cm width. We then add on a centimetre or two to allow for driver error in the field to end up with 56cm theoretical inter-row spacing.
Intra-row spacing is based on module planter and seed drill settings – specific to each crop and their needs. Once these two figures are inputted, column C is automatically calculated.
We then take the total volume figures from the ‘customer volumes and value’ spreadsheet and input them into column E for each crop. Column F is needed because each crop yields differently – e.g. a cabbage is sold as a head and is therefore 1 item plant, whereas spinach is picked for its leaves and sold by weight so we have to estimate how many kilograms we’ll get per plant. For radish, each plant amounts to 0.066 of a bunch, because there are an average of 15 radish per bunch.
Once this is inputted, the spreadsheet will calculate the number of plants required. We make sure this calculation (in column G) factors in a 35% crop failure – to allow for lack of germination, pest damage, and anything else that prevents us from selling a crop. (In future years, as we get more knowledgeable and have more evidence from previous years, we might have a specific percentage failure for each crop, so this spreadsheet becomes more accurate.)
And finally, we end up with the area of land that’s needed for each crop (column H), and each crop family (at the top of column H – not calculated properly in our example spreadsheet because we’ve only filled in two of the crops). This has to fit within the areas we have for our growing blocks (top of column B), otherwise we need to revise the plan with our customers.
(n.b. We also use this spreadsheet to estimate costs of modules or seeds (columns J & K), not just for the growing season ahead (based on known demand from customers) but also for hypothetical future years. We then transfer this information to our forecasts.)
Having gone back to our customers, we settle on some final target volumes for our crops, and fill in the ‘target volumes & values & hours’ spreadsheet (LINK to attachment) – just the first page of this spreadsheet; see section 6 with regard to the ‘hours’ page. An important consideration at this point is whether we want to allow for extra demand from potential new customers that we don’t yet know about – in essence, whether we feel bullish about the market or not. If so, we nudge up the numbers. Equally, if we feel any sense of our customers over-estimating their demand (perhaps based on previous years’ evidence) or a general gloomy forecast for the market (e.g. economy entering a recession), then we might nudge the numbers down.
(3) look into variety options
Within a few years we’ll probably use very similar varieties year-to-year, but before we get to that stage there are plenty of varieties for us to try out. (Plus, in any case, there are always new varieties being released by the seed companies each year.) We weigh up five aspects in our variety choice:
(i) most of all, any evidence we have from previous growing seasons. We try to give every variety at least two seasons of evidence, as no two years are the same
(ii) if we’re buying modules, we find out what the plant-raisers offer (see section below)
(iii) what other growers grow. Local evidence, especially, is really useful
(iv) information from seed catalogues
(v) NIAB / HDRA trial results – vegetable variety evidence from over 200 trials, covering over 450 varieties, last done by the National Institute of Agricultural Botany and the Henry Doubleday Research Association in 2007. We bought this book from the Soil Association.
At this stage we start compiling all the information in another spreadsheet, ‘seed options’ (LINK to attachment), which compares varieties and suppliers, as well as prices for those crops we’ll be sowing. Anything that’s module planted, we don’t bother with seed prices as this is included in the price we pay plant-raisers.
(4) contact plant-raisers and get quotes
We order modules from two different places – one a large nursery with national distribution (Delfland Nurseries) and the other a small local market garden (Glebelands City Growers). We’ve found this mix works well for us because they both have their advantages:
- the large nursery – has the best prices. They’ll grow anything to order but offer the best prices (to small growers like ourselves) on varieties that they’re already doing for other (larger) growers. The main limitation is that there is a minimum order per variety of 1,000 modules. Delivery costs can be high, so we tend to amalgamate different crop orders so they come on the same truck
- the small local nursery – is more expensive but can deal in whatever volumes we like, of whatever variety, and there is a lot more flexibility as to when we pick up the finished seedlings, which is really useful at times when the ground is not ready or suitable for transplanting
We find that we need to get an idea of price and volume from our plant-raisers before making our final choices, because it affects the soil prep plan (see next section). To use the example of Savoy cabbages, we know that we need to buy in 7,000 modules. This is easily enough to be asking the larger nursery to raise them for us. In choosing the varietes there are some that are unjustifiably expensive, so we rule them out at this stage.
(5) work out a week-to-week plan
This is quite a labour-intensive part of the plan, but possibly the most important. We use a ‘growing schedule’ spreadsheet (LINK to attachment) – it’s fairly self-explanatory, but takes a while to compile (there’s probably a clever database that could do everything we wanted, but we haven’t worked that one out yet). We are just filling in columns A to J at this point – see section 6 for how we use the rest of the spreadsheet.
The basic idea is to work back from the weekly demand that our customers told us and the ‘target volumes & value & hours’ spreadsheet that we settled on. We can then plan when to sow or plant a crop – based on our own experience, or seed company info – and then, one step on, when to plough. We generally aim to plough 4 weeks before sowing a crop, or 3 weeks before module planting (see section 4), but to give some margin for error we just say 4 weeks for everything on this spreadsheet.
We then refer back to our ‘crop areas’ spreadsheet in order to work out how much land needs to be ploughed for each sowing or planting of crops, with a total area highlighted per growing block per week.
The difficult part of this process is estimating the length of time between sowing / planting and harvesting, as there are various factors involved. Each crop is different, and each variety of each crop too – some are early varieties, mid-season, late etc. Some crops stand very well in the field, which means it makes sense to plant more at once – for example, leeks. Others don’t last in the field and therefore need to be programmed quite carefully – for example, spinach & radish. Length of maturity also depends on the time of year – for example a quick growing radish will take longer to mature in early spring than in early summer. We try to base our estimations on previous years’ evidence, as well as seed catalogue information.
To take the example of Savoy cabbages, the ‘crop areas’ spreadsheet says we need to plant c.7,000 modules. The ability for Savoys to hold in the field mean that we are happy to plant once a month, from April to July. The spread of modules we will order from the plant-raiser reflects the spread of customer demand, as well as this holding ability. With the example of radishes, the difference is that we feel we need to sow twice a month in order to maintain successional availability.
This ends up being the most important document for the year ahead – a framework of tasks that we refer to throughout the season. It’ll be a rare season when this schedule is followed exactly but, through all the adverse weather or other distractions, it remains a vital guide.
(6) order modules
We get back in touch with our plant-raisers and confirm our order.
(7) buy seeds
Using the information we’ve compiled in the ‘seed options’ spreadsheet, we choose our varieties and the seed companies we’ll be buying from. We’ve found most of the seeds we’ve bought to be reliable enough, from whichever seed company, so the choice tends to come down to price – though we also need to watch out for minimum orders and delivery costs. These are the companies we look at:
Most of these have different catalogues for commercial growers and for home-scale growers.
Costs of production
One of the most useful tools that we have for assessing our individual crops, either before, during or after a season, is our ‘costs of production’ spreadsheet. This is currently being re-developed through our involvement in Manchester Veg People, a local co-operative of organic growers and catering industry buyers, in an effort to move beyond the distorting and unjust effects of supermarket power on ‘market prices’. At a practical level, for us growers, it’s a tool that will quickly tell us if a crop is viable or not.
Essentially all the spreadsheet is doing is acounting for every element of our business costs (getting a per-acre cost for it) and matching those costs up against the yield of each crop. We will attach it to this section once the new spreadsheet is ready.
Record keeping & analysis
These are the records we keep during the season:
(i) in order to distinguish between varieties
- keep a map of where different varieties grow
- record average harvested weight per plant per variety
(ii) costs of production
- record time taken to do all jobs (both growing and non-growing related jobs) and the area or volume done in that time – i.e. end up with an average kg/hr or ha/hr rate
(iii) general forecasting and crop planning
- record monthly volumes per crop
- weekly sales (£ value)
- keep a note of average weekly volumes to different customers
- keep ‘growing schedule’ up to date, recording when areas were ploughed, sown/planted and harvested
- rainfall – using a measuring cup (from LBS Horticulture)
- temperature – using a minimum and maximum thermometer (also from LBS)
(v) other notes
- particular pest or disease damage on each crop
- observations on plant growth and health
- effectiveness of machinery (especially sowing, planting and weeding)
There are undoubtedly other aspects that can be good to record, but these are the basics that enable us to sufficiently analyse our production at the end of each season. We mainly want to know:
- actual yield versus expected yield and a wastage figure for each crop (i.e. more than our 35% threshold? Any mitigating factors, weather or otherwise?)
- actual time spent on each crop versus predicted labour costs (i.e. did we spend too many hours on a certain crop? Should our sale price be higher or lower?)
- actual demand versus predicted demand from customers
- actual income from a crop versus anticipated income
- looking at each customer – how much trade? What’s the average speed of payment?
- overall, what varieties worked best? And which crops are profitable?
- any fertility issues or machinery needs for next year?