Planting in clay soils is one of those oft-debated horticultural practices.
Essentially, research showed that trees and shrubs planted in heavy clay had two responses:
If the soil was amended and made very rich within a planting hole – the woody plant would establish and grow very quickly but when the roots hit the clay soils on the edge of the planting hole, they would tend to turn back towards the good soil.
Plants stalled out and became ‘root bound” within the planting hole. It would take a few years before the roots would venture out into the native clay.
The plant during this stalling out phase was more vulnerable to flooding with heavy rain or drought conditions.
Response #2 (The Preferred One)
If the soil was simply turned over but not amended – the woody plant was slower to establish itself but once it started growing, it grew consistently and wasn’t as stress prone as the more pampered plants.
The lesson learned within the hort trade then has been to not amend heavy clay soils when planting.
And that’s the other lesson – only use appropriate plants.
Trying to force fit a plant into a soil for which it is not genetically adapted is a waste of money and good garden plants.
Your choice as gardeners then with trees/shrubs and perennials is to find plants that deal with clay or totally amend the garden so you can grow the plants you want.
This means that growing something like lavender in a heavy clay soil is going to be tricky unless you modify the entire area that influences this plant’s growth.
The lesson here? Pick your plants for your soil. Because anything else is just a waste of time, money and good plants.
2 thoughts on “How You Can Plant Perennials and Shrubs In Clay Soil”
I am truly green when it comes to gardening. But I want my plants to LIVE! = 🙂
I have been reading a lot of info from various sources.The info is as varied as the source.
My questions . . . I want to plant a Forest Pansy and a Japanese Bloodgood maple. I have clay soil . . . . amend the soil or don’t amend the soil?
OK, so you read the article here and the bottom line is to “not” amend the soil for perennials and shrubs. And you saw the two lists of plants (linked) that would handle the clay soils. I suspect what you’re calling Forest Pansy is actually the Redbud ‘Forest Pansy’ (small tree) and this is not a plant for clay. Japanese Maple are similarly not plants for clay soils. And that’s the problem those of us with clay soils face. You can change enough of the soil for annuals and vegetables and maybe perennials but the size and root spread of shrubs and trees means we’re pretty much reduced to growing plants that survive/thrive on clay. Is there a way? Well, if you built a massive raised bed – 2 foot deep – and at least 15-feet wide and long – you’d be able to keep those plants alive with a bit of extra water. But without that, I’m sorry but adding organic material to the planting hole isn’t going to help. The life of both of those plants will be relatively short and struggling in a heavy clay. If this isn’t clear or I’ve missed the point, do let me know.