Personally I don't think you should buy topsoil. I think you should buy compost and mix it with your existing soil.
I am putting our vegetable garden in and our drainage is is not very good. I think I have to raise the beds at least partially. I never had beds boarded up, mainly because of the costs, but as well as it might not be good working. What do you think? I would get hardwood boards for $6 the meter, which is quite reasonable, but in the end very expensive.
Putting drainage pipes in is a bit too backbreaking.
I might ask an excavator for topsoil. Is this a good idea? If I buy vegetable garden soil from a landscaper this is $50 the m3 and I have not control where the stuff comes from. I would buy some manure as well.
We are not very long in our house and the compost produced is all used up.
What you are suggesting is a raised bed but instead of heaps of compost or other organic matter you use rock dust from a quarry. What is the rock dust for?
I ask a lot, because I never heard of anything similar.
We have sandstone here and sandy soil with clay.
Why do you suggest to bring something in what I have anyway or could (maybe) get very cheap from an excavator?
I try to get as much lawn clippings from mowing contractors as possible. Our ph is around 7 in an area where usually azaleas and rhododendrons are grown!
The second type of organic matter I can get for free is prunings, heaps of them I simply cut out what's classified as "environmental weed". If I would call gardeners it would even be more. And we have around 3 buckets of woodash, which I didn't apply to the soil so far because it is so alkaline.
One thing I highly recommend which has revolutionized my approach to my garden site is to put in an "observation well" to monitor the depth to your water table. I sank a 3/4" pvc pipe 8' deep using a garden hose to blast it's way down. Not too hard once you get the hang of it and a good nozzle worked out. Now I don't guess how waterlogged my soil is, I know. The water table was far shallower than I had though (4-5' is the deepest I've seen it so far. It's 27" right now after a flooding rain two weeks ago which brought the water table to the surface.)
My plan is to get a Berta rotary plow and use it to dig ~2' ditches around the perimeter of the garden to drain surface water toward the SLIGTHLY lower corner of my very flat property. Then also to build up ~10" beds in the garden. Then be diligent about pumping out the sump/pond in that low corner after heavy rains.
If this fails then I will consider renting a trencher to get drainage tiles down 4' deep and putting in some sort of concrete/septic tank-like sump to collect the water for pumping.
Best solution: don't put garden in a low spot!
True. Why not dig a pond or some other type of catchment not requiring pumping out. Pump it out to irrigate your gardens during drought. Just let the gardens drain into the pond. If your property is flat just make sure your pond is deep enough to handle heavy rain, retaining most that flows into it across the watershed.
All you have to do is cut drainage trenches to the same depth as the bottom of your garden beds. Run these trenches into your pond or into swales and then into a pond.
Do you dig an open drench or do you cover it somehow? What dimensions do you dig?
I dug some observation holes throughout the garden, but not that deep. And we have one bigger maybe a meter or so deep (we transplanted a tree) which is now a duck pond after rain.