By John Curtis
Some of the reasons for growing in rows are down to what is good for farmers with tractors, so may not be of relevance to amateur growers. Here’s my take on the dilemma.
Construction work and upfront costs
Carpet tiles used as edging for beds. Photo: John Curtis
Making raised beds definitely isn’t the simplest or cheapest option to get started. You normally need to buy some wood and do some construction. People sometimes ask if they should use woodstain on the wood, which is a chemical that might leach into the soil, or not bother and accept that it won’t be as durable. I don’t think that there’s a clear-cut answer to this either way.
We’ve tried using cut-in-half carpet tiles, rescued from skips, as bed edges. They work reasonably well since the backing used on them is fairly stiff so they don’t bend too much, although when you accidentally kick them, they do go a bit wonky. Some people have raised concerns about the chemicals used in the manufacture of carpet and carpet tiles which might leach into the soil, so this is something to bear in mind. Something else we’ve tried is slates from an old roof. They work well, but it’s painful if you bash your knee on them, and they crack easily if you accidentally kick them.
Whatever you use as the edging for raised beds, if you change your mind and want the beds rearranged, eg for wider paths, you have more work to do and possibly more wood to buy to move the beds. With rows, you don’t have that problem – restructuring your growing area is trivial.
Beds don’t have to be boxed in, in which case they are sometimes called ‘fixed beds’. You can use old carpet or a weed control fabric to cover the paths, which suppresses weed growth and marks the positions of the beds. Alternatively, you can grow grass or a green manure on the paths, and put the mowings in the compost bin or use it as a mulch. There’s no other boundary, so fixed beds avoid the cost and construction. Some people dig out the soil in the paths and put it on the fixed bed so that it mounds towards the centre, gaining some of the advantage of deeper soil in raised beds. Don’t be tempted to make the bed flat with steep edges at the sides – the edges crumble very easily.
If you have beds with paths between to walk on, the normal recommendations for the path width tend to range between 30 to 45cm (12-18″). The pro rowers might argue that this is lost space, and they have a point. That said, if you grow a large crop that needs to be widely separated, such as potatoes or sweet corn, and you haven’t dug out the soil where the paths were and put it in the beds, the roots of the crops in the beds will grow under the paths so they will take water and nutrients from there. Their foliages will grow outwards and to some extent fill the gap created by the path, so pretty much all of the sunlight shining on it is used by the crops. If fact, I find it difficult to walk on the path between beds of established potatoes and sweet corn – they really do hide it well.
Normally more space is lost when growing in rows too – you have to walk somewhere!
Soil compaction and maintenance (digging)
One of the big arguments against growing in rows is that because you walk all over the plot, the soil gets compacted so you have to dig it in the winter to loosen it again. With beds you have this rule that you only walk on the paths, so the beds don’t get compacted and annual digging isn’t needed.
I think it’s an exaggerated point – winter rain seems to cause more compaction than walking on the soil, but every little way that you can lessen the compaction helps. Just as some people like sport, some people like digging, so there’s some personal preference here. If you do grow in rows, try to walk as little as possible on your plot when it’s very wet since wet soil compacts much more readily.
But there are rows within beds
It’s true – most people who have beds grow things in rows within each bed, and with good reason. It makes weeding with a hoe much easier and, just after germination, it’s easier to distinguish your neat row of seedlings from the random positions of weed seedlings.
With rows, you need to remember where the rotational areas are, eg four areas if you have a four-year rotation. With beds it’s simpler – you just need to remember which set of beds correspond to which parts of the rotation. Rotational areas are sometimes more difficult to divide up in beds. For instance, if you have seven beds for rotation but decide to follow a three year rotation, you have the 7 doesn’t divide into 3 problem to resolve. If you have your rotation just right (eg eight beds and a four-year rotation so two beds per rotation) it’s annoying if you decide to take one of the beds out of the rotation, eg to use for permanents such as bushes, or if you install a greenhouse on it. The seven remaining plots no longer divide neatly into four. This problem is something that you don’t get when you grow in rows.
It’s said that slug problems are worse with beds – slugs have more places to hide, especially under covered paths, so that’s something to be aware of. If you have raised beds with a continuous boundary all the way round and minimal gaps, you can put copper tape around the raised beds to discourage slugs and snails from getting in. The boundary (normally wood) needs to be buried several cm deep to prevent them from burrowing in, and there’s likely to be slugs already in the raised beds, hiding in soil crevices. Collect these at night with a torch and move them on to some waste ground far away.
Mind your back
If all the bending down gives you backache, raised beds are definitely the way to go – they bring the growing space upwards, so you bend down less.
Drainage and drought
If you have drainage problems, the higher soil surface of raised beds takes the soil further away from badly drained soil below. On the other hand, if you don’t suffer from water logging and your soil tends to be dry, raised beds are not so good in a drought.
Raised beds in small gardens
Whether it’s beds or rows, applying rotation is tricky if you only have a small garden. My advice is to have raised beds which fit the space that you have, so they might not be rectangular, and to add lots of compost to enrich the soil more than you would in a larger garden. Don’t rotate in the normal 3, 4, 5, etc year cycle, but just plant something else when a bit of space becomes available when the harvesting of a previous crop has been completed.
This article appeared in Growing Green International magazine Num 32 (Winter 2013/14), p34, but compared to the original article has been updated and expanded.