Garden Bathtub Clay amendment

That is indeed an ugly situation. Perhaps it is time to learn a bit of masonry to build some permanent raised beds?

Apply a generous amount of gypsum (calcium sulfate) over your entire garden. A layer 1-2 cm would be about correct for a start. Lightly wet it down so that the wind does not disperse it. If you get some rain, that would be good because it needs to be dissolved and rinsed into the soil. Without rain, you need to lightly water it about once every three days until you do not see it. Repeat this treatment once over your entire garden. Then repeat it at least two more times in the areas that tend to have the worst drainage.

Gypsum reacts chemically with clay, making it granular and porous. That improves drainage. Unfortunately, you might have to give another treatment at least annually.

Another thing to consider is adding peat moss when you "rotavate" (which we call "rototill" in the U.S.). Unlike many other organic amendments, peat moss decomposes very slowly. For your worst soil, try tilling about a 15 cm layer of peat moss to a depth of 30 cm.

DO NOT add sand to your clay. Adding sand to clay is equivalent to adding gravel to cement to make concrete.

In the end, you might have to make a dry well at the lowest end of your garden.

mattyvx wrote: ...

for a poorly drained area if you have no alternative you can dig it out so that it will fill during your worst storms and then use it to plant a low growing and water loving plant.

this is the cheapest method considering what it may take to put in a drain or all the other suggestions for amending.

creeping jenny works for me to cover a low area, but it looks nice if kept weeded otherwise the taller weeds will eventually take over. except it may be considered invasive and spread so... i don't mind mine spreading. if it gets to be too much i'll just use it as a mulch. it's not gotten that far yet. :)

i started with just a few cuttings and then kept taking more chunks as it grew to fill in the area. it took a few years to get the whole area covered. i have to spend a few hours here or there to weed it, but as it has filled in the weeding goes much more quickly.

grasses are the biggest pains in the ass.

the suggestion of a dry well could also work but is more expensive because you need a large enough container and grate of some kind.

songbird