Raised, bordered vegatable beds (Something to think about)

The construction and material choice for raised or bordered bed systems is seemingly vast and endless, as are the opinions of material choice and construction methods. Bed size, treated or untreated timber, all lay waiting to confuse anyone wanting to start out.

Detailed below is my chosen method of construction. I'm not saying that it is right or wrong, only that it worked for me.

The vegetable garden hadn't been touched for many many years, and the first job was to clear the site. Bonfires were the order of the day, then a mini digger was used to double the site and install some land drainage pipes. Thankfully the site was pretty much level to begin with, so this made life much easier.

Once the site was clear and level, the setting out process could begin. For once in my life I actually decided to draw the project out as a scale drawing. Something that was well worth doing as it gave me scope to cut out and design the beds sizes just as wanted them.

Through research and asking questions, I decided that the outside pathway should be 900m wide and the the pathways that run throughout the bed system should be 700mm wide, which is ample room for a wheelbarrow. In hindsight I could have just made the outside pathways 700m as well.

The first job was to set out the outside pathway edging. The material choice for this was 100mm x 25mm sawn pressure treated timber and the pegs to fix it were 47mm x 47mm sawn pressure timber. To save money I bought the timber for this in 5.4m long lengths and then cut and pointed them my self to suit. This saved quite a junk of money. The edging board was joined together in one long length, set in position using steel pins, then leveled using a laser level. Peg distance were set at 650mm centres, and positioned by first making a whole with a steel crow bar, then they wee banged in to a flush level, fixed with two screws per peg, then finally a back weather was cut using a hand saw.

 Lovely sleet and rain!

The material choice for the actual beds was 200mm x 47mm pressure treated timber, bought in  5.4m and 4.8m long lengths. 4.8m lengths were chosen as I wanted the beds to be 1.2m wide, and this length gave no wastage. 5.4 was chosen as I wanted some of the beds to be 2.7m long, so again no wastage. Once again pegs were 47mm x 47mm by 4.8m cut and pointed to 600m long lengths.

The first job was to paint them to help preserve the timber further. In hind sight this was a waste of time and money, as the paint turned out not to be UV resistant. It was fine below ground, but not above.

The bed system was constructed by first cutting the material to the chosen length and width, followed by screwing it together to form a bed shape. The bed was then aligned in position using a string line that had been off set. Steel pins were used to help keep the position of the bed, and a laser level was used to set the height. Each bed. Once I was happy with everything pegs were driven into the ground at approx 650mm centres, after having first made a hole with a steel bar. The pegs were banged in flush, screwed with 90mm screws and a back weather was then cut. I prefer to use screws over nails, as they can be adjusted, and also there is no risk of knocking pegs loose. When putting in the corner pegs, keep them approx 100mm away from the corner. There is a reason for this. I also found that whilst very long beds are lovely, a bed size of 1.8m x 1.2m seems to be the ideal.

Anyone thinking of doing a project such as this, take a look at the modular fruit cage/plant protection sizes first. It would be a shame to make your beds, then discover that protection is awkward to fit or adapt.

As the beds were being created, I also wanted to start the foot paths. A terram membrane was laid down first followed by hardcore, then compacted Fittleworth stone. Obviously anything from carpet to grass will work for pathways.

  
And this is the finished result.  

One problem that I feel all raised/bordered beds suffer from is rot and mould! Wood treated or un treated only has a limited life span when in contact with soil. With this in mind, one thing that I would recommend is that in winter, dig the soil away from the edges of the boarding on the beds that aren't being used. That is the reason for keeping the corner pegs in by approx 100mm. It gives you space to clean right into the corners, the other reason is that 100mm gives plenty of room to erect a fruit cage.

I am afraid that I am not the person to advise on soil make up etc, but slowly, I am removing the soil from each bed area to a depth of 450mm, sieving it and mixing it with sharp sand, then putting it back. It certainly makes a massive difference to the quality of root crops.

I shall write about the irrigation system next.

Something prompted me today that I hadn't finished this thread in relation to the irrigation system.

It seems a very long time ago now that I constructed this, but the first job was to lay the concrete base for the IBC's to sit on. An over flow pipe was also installed at this stage.

Once the concrete had cured, the IBC's were placed on the concrete base and then they were linked together. All six tanks are linked at the top, but only five of them are linked at the bottom. Rain water enters the first tank, fills this and then the tanks are filled one after the other. The first tank also act as a sump which is why it is not connected at the bottom to the other tanks. I am able to open this tank separately in order to flush out any debris. The remaining tanks whilst being linked, can also be shut off individually.

From the linked tanks, water is fed via gravity into a buried animal water trough. The trough has a ball valve similar to that of a domestic toilet systern which controls the amount of water in the trough. From this trough we are then able to fill watering cans. There is also a tap fitted to both outside tanks, which allows a hose pipe to be fitted. Sometime in the future I hope to fit an electric pump to the system, but the logistics of getting power to the tanks isn't that easy.

The overall water capacity is 6000litres, which whilst sounding a lot we seem to get through it at quite a rate. The only issue that I have had is trying to work out when to start to filling the tanks after having drained them down in the autumn. I left it too late year and we had run out by April! The tanks are currently full, but I'm not keen on keeping the water for longer than is necessary. I have found that whilst it is usable even after long periods of storage, it only manages to keep plants/veg alive rather than helping them to put on grow. This point is very obvious after a sustained dry period where the plants aren't really putting on much grow, but get one night of decent rain and the shoot off.

Since taking the above photos I have gradually been covering the tops of the tanks with old leaves etc to help keep the sun off the tanks to both keep the water fresh.

I guess that the composting system is next on the list to write about.

Eddie J wrote (see)

 I have found that whilst it is usable even after long periods of storage, it only manages to keep plants/veg alive rather than helping them to put on grow. This point is very obvious after a sustained dry period where the plants aren't really putting on much grow, but get one night of decent rain and the shoot off.

I have also found watering from an outdoor tap is not the same for a plant as rain. I would love to know what the difference is if anyone knows? I always thought it might be chemicals but since Eddie is storing his water that would prove otherwise, but there is definitely a magic ingredient when it pours