Trial mini wicking bed

Our large wicking beds have been such a success for us, but are costly and time consuming to make. With the recent complete failure of my pumpkin seeds planted into a normal garden bed, to turn into anything more than weedy, bug infested miniaturised versions of what they should have been due to what I believe is just a lack of water I decided to try to produce a quick, just for pumpkins that will sprawl all over the ground, mini wicking bed. For those not yet familiar with wicking beds they are just a garden bed that has a reservoir or catchment area under them that enables them to hold water. This water naturally wicks its way upwards through the soil providing a ready supply of water to plant roots.
I have been inspired recently by the blue shell shaped plastic sand pits/swimming pools that you can buy from Bunnings. A neighbour had been using one as a makeshift pond for some ducks and ducklings that had made their way into her backyard. With an approximate diameter of about 3 foot or 90cm and at only $12.50 they seemed a good size and value for a purpose made wicking bed.
With my large wicking beds we needed to find a way to waterproof the bases to hold water and then needed a bed of sand to protect the plastic sheeting used. The shell being hard plastic meant these steps weren't needed. As our yard is on quite a pronounced two way slant and I wanted the pumpkins to base their roots here and know the vines will spread out across the yard I dug a hole to partially submerge the shell and to make sure it sat perfectly flat using a spirit level.

Shell showing spirit level, coiled socked Ag pipe and stones to fill gaps.

From there I wanted to trial using an alternative to the rock water holding sections we'd used in the large beds. The rocks were back breaking work to shovel into the large beds and because of their rough edges it meant the necessity to once again protect the plastic linings in the originals with more sand, again more shovelling  and the use of heaps of geotex fabric (fabric used in ground work which allows water to pass through but not soil or sand) to keep the water holding area between the rocks free of sand and dirt to allow it to hold as much water as possible. Our alternative was socked Ag pipe left over from a drainage system my parents had put in. Ag pipe is used in drainage systems, it's just black piping with slots cut in it to allow water to drain out. The "socking" on the pipe we used means that dirt doesn't get into it. Thus allowing us a water holding pocket without needing to use geotex to keep the sand and dirt out. We wound this into a tight coil using some wire to keep it held together, then threw a couple of rocks in to the holes around the edges to ensure as much water holding capacity as possible. An outlet pipe is added at this time to allow any excess water to be drain away and to prevent the whole shell from just filling up with rain or over watering and the plants drowning. I recommend using a small piece of weed mat wrapped around the end of the pipe on the inside, once again just to stop the loss of any dirt as the water flows out. We used some left over grey water pipe as the fill tube to take water down to the larger pipe. This isn't strictly necessary as you could just water the soil and it will drain down itself but using the pipe puts the clean water right where it needs to be. This was then topped with some left over weed mat to minimise the above layers getting down into the water collection area (not as good as using geotex but we had none on hand, and it's fairly expensive and best bought in large rolls which we aren't needing just yet). This is then topped with some sand for it's great wicking properties and then soil added.

Feeder pipe to the top left and outflow pipe to the bottom right. Shell filled and ready to go.

As pumpkins are heavy feeders we used part of the sandy loamy soil we'd dug out to bury the shell, but mostly the larger part a rich dark compost and part composted cow manure hence the very dark soil in the image above.
For the first couple of weeks until the seedlings came up each time the chooks were out we used a matching shell lid to keep them from digging, but relented and put a temporary wire fence around it as the chooks were way too interested in that dark soil.
In went a few Marina Di Choggia pumkin seeds from Green Harvest (lovely warty looking pumpkins) and in a few weeks we can safely say all seems to be going well. In fact it seemed to hold water so well I couldn't resist throwing in a couple of lettuce seedlings to take up a bit of space while the pumkins got underway.

Little garden growing well. You can see from the grass around it just how dry it's been here.

The final verdict, I'm really pleased. It holds a tremendous amount of water due to the large space provided by the Ag pipe (in fact when I fill it after 5 very hot days in will take approximately 30 litres of water before the overflow kicks in). It was very easy to do and the cost was minimal courtesy of some leftover grey water pipe and Ag pipe from previous jobs. The Ag pipe works so well and holds so much more water for the volume that I think we will use it in the next large wicking bed instead of the large quantities of rocks we normally use.If you're having trouble with dry garden beds I'd really suggest giving this easy wicking bed a go.