Gardening in Clay or Poorly Drained Soil
Clay soil is one of the most difficult conditions
a gardener can face. Dense and slippery when wet, it's even more of a challenge
as it bakes brick solid when dry. Clay particles are extremely small and tend to
pack together, leaving no room for air or water movement.
The first order of business here is to improve
the texture of the soil with organic matter. This will be an ongoing process,
but the benefits will pay off in the long run. Generously amending or top
dressing with compost, leaf mold, composted manure, good top soil or other
organic matter will gradually bulk up the texture of your soil, lessening the
compaction. The good news is that clay tends to be much higher in nutrients than
a sandy soil.
WE STRONGLY ENCOURAGE YOU TO CONSIDER RAISED PLANTING
BEDS! A huge part of gardening is how well the soil is prepared. But if
you absolutely can't...
If you can’t amend and raise the whole bed, at
least work and amend the soil in the planting hole and add enough material to
raise the planting area about 4-6“. Most PERENNIALS need a depth
of at least 8” in which to grow. For quarts at least a 12” by 12” hole
should have the soil removed and mixed with Compost/Amendment (mixed not
replaced). The bottom of the hole should have a higher clay content than the
top of the hole which should have a higher Amendment/Compost content. Notice the
shading from light to dark in the Amended hole on the left photo -- more clay at
the bottom, more compost content at the top. SHRUBS will ultimately need
a larger space in which to grow than 12” by 12”. Use the ultimate size of
the shrub as a guide.
The clay surrounding this planting hole will
still not drain if it rains a lot (see photo on right). It’s still a water
holding clay bowl. But by amending the soil and leaving the planting area raised
above the clay, with half of the new plant’s roots
completely above the clay level, the plant should do fine, even in a wet
season. Mulch can ‘soften’ the mound, so that it blends into the rest of the
and Debby Sheuchenko