The Sensible Gardener

The right plant in the right location with the right conditions

Clay soil clants

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Roses are good clay soil plants

Roses are good clay soil plants

Clay soil plants thrive in soils rich in clay. Although clay may be rich in nutrients, most plants don’t do very well in clay-rich soils. Poor drainage and lack of sufficient aeration make it hard for plants to take hold and grow in such soils. Clay soil plants, on the other hand, have good chances of making it, granted that you help them a bit by working the soil, so as to make it more permeable to water and air.

How can I know what kind of soil I have, you ask?

  • The best soil to grow most plants in is loam, which is made of clay, sand silt and organic matter. This is a good combination that is rich in nutrients, that can hold water but drain well, that is light enough to let air in, and that sustains microbial life and plant life as well. If you take some wet loam in your hands and mold it into a ball, it may hold its rounded shape, but the ball will look granular and somewhat crumbly. Let it dry and it will crumble.
  • Plants that dislike having wet roots will tend to prefer sandy loam, which is simply loam with more sand in it. Sandy loam is a bit poorer than loam, but it drains very well. Too well, in fact, for plants that prefer richer, cooler soils. If you try to mold dry or wet sandy loam into a ball, it will never hold its shape.
  • Clayey soils are dense, sticky when wet and hard when dry. If you take some wet clay soil in your hands and mold it into a ball, it will hold its rounded shape. Let it dry and it will become a hard ball of dry clay.
A few images of clay soils

What Clay Soils May Look Like

Clay soil plants are simply plants that have adapted to heavier, harder soils that don’t drain as well. They have strong roots that aren’t as affected by excess humidity. And the great thing is that when clay soil plants start to populate a location with clay soil, their roots eventually make the soil more permeable to water and air. As they push their roots through the hard soil, they make it more permeable, and thus better at sustaining life. Never forget that what makes life possible above ground is the life happening below ground: the billions of organisms and microorganisms that live and die and that make the soil fertile.

Note that if you have a specific lawn drainage problem, you may need to do more than simply introduce clay soil plants on your yard. For more information on this topic, see our page on Lawn drainage.

Giving clay soil plants a fighting chance

Although clay soil plants may be well adapted to clay soils, it is essential that you give them a fighting chance.

The following factors are essential to your success:

  • Chose your planting period well, so as to ensure that the new plants won’t sit in water for too long or be exposed to excessive cold. Spring is usually the best period.
  • For each plant, you must dig a hole that is at least four times as big as the root ball. This will give some space for the roots to grow with ease in the first few months. This period is often critical. You could call it the “Do or Die” period. So give your plants and their roots a chance to gather strength and make it through.
  • You must use a garden fork to break up the clay around each planting hole and at the bottom of the hole as well. This will prevent waterlogging, when all the rain water ends up in one place and just sits there forever.
  • In each planting hole, use some clay soil mixed in with lots of organic matter (mostly composted leaves and bark, but also a bit of manure). Commercial composted bark amendments from Gro-Bark, Eco-Soil, Fafard and Scotbark, for instance, are all good clay breakers. From day one, they will make the soil richer and more permeable to water and air, promote microbial life, and give your clay soil plants a real boost. In the long run, compost and bark amendments will change the chemistry of the surrounding clay soil, and make it better for growing an even larger variety of plants.
  • For larger plants that may be tipped by the wind, use stakes that you will drive into the hard clay soil.
  • Once your new clay soil plants are in place, if you see that the soil in which they grow tends to dry up too much, simply add some mulch (see Mulching machines) around each plant.

Types of clay soil plants

You can choose from an interesting variety of plants, including deciduous trees, conifers, shrubs, etc. Browsing the following lists should help you find plants that correspond to your tastes and needs. As you are gathering information on plants that may interest you, don’t forget to verify mature sizes, needs in terms of sun and water, hardiness, etc.

Deciduous trees

The following deciduous trees are good clay soil plants.

Scientific name Common name
Acer japonicum Japanese maple
Acer palmatum Smooth Japanese maple
Amelanchier lamarckii Juneberry
Betula Birch
Crataegus Hawthorn
Eucalyptus (most species are actually evergreens) Eucalyptus
Laburnum anagyroides Common laburnum
Liquidambar styraciflua American sweetgum
Malus Crabapple
Pyrus salicifolia ‘Pendula’ Weeping pear
Sorbus Sorbus

Conifers

The following conifers are good clay soil plants.

Scientific name Common name
Abies koreana Korean fir
Araucaria araucana Monkey tail tree
Chamaecyparis lawsoniana Lawson cypress
Chamaecyparis obtusa Japanese cypress
Chamaecyparis pisifera Sawara cypress
Ginkgo biloba Maidenhair tree
Juniperus chinensis Chinese juniper
Juniperus virginiana Eastern red cedar
Picea abies Norway spruce
Picea glauca White spruce
Picea pungens Blue spruce
Pseudotsuga menziesii Douglas fir
Taxodium distichum Bald cypress
Thuja plicata Western red cedar
Tsuga candensis Eastern hemlock

Shrubs

The following shrubs are good clay soil plants.

Scientific name Common name
Berberis Barberry
Buddleja Butterfly bush
Cotoneaster Cotoneaster
Hydrangea Hydrangea
Mahonia Mahonia
Rosa Rose
Spiraea Spirea
Viburnum Viburnum
Weigela Weigela

Ground-covering plants

The following shrubs are good clay soil plants.

Scientific name Common name
Bergenia Elephant’s ears
Euonymus fortunei Wintercreeper
Gaultheria procumbens Eastern teaberry, wintergreen
Geranium Geranium
Hypericum calycinum Rose of sharon, Aaron’s beard
Juniperus communis Common juniper
Juniperus horizontalis Creeping Juniper
Lamium galeobdolon Yellow archangel
Persicaria affinis Himalayan fleece flower
Persicaria vacciniifolia Rock knotweed
Rubus pentalobus Creeping Raspberry
Vinca major Bigleaf Periwinkle
Vinca minor Lesser (dwarf) periwinkle

For information on landscaping plants in general, bne sure to have a look at our Landscaping plants page.

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5 Comments

  1. I have seen a lot of lists of plants that tolerate clay soil like this online, but most of them are nothing but lies and slander (and have inspired me to waste large sums of money buying plants that have ended up dying). I can say, without any hesitation, that this is probably one of the most accurate lists I’ve personally seen. I have really heavy clay soil, and the things I’ve planted that have actually survived it are all on this list (butterfly bushes, hydrangea, weigela, spirea, roses, juniper, rose of sharon). I can’t wait to try planting some of the other plants you’ve listed here! In other words, thank you!

  2. Thank you! We are new to an area of clay soil under trees (no sunshine) and I have had a difficult time getting anything to grow. I planted azaleas & hydrangeas & they are alive, but not growing well. Perhaps I need to dig a much larger hole & amend soil before planting.

    • Clay and shade. Not the easiest of conditions! And that’s an understatement. If the conditions are better when the plants are introduced, they get a chance to grow strong and it makes it that much easier for them to survive and establish themselves. As it says on our page on clay soil plants, break up the clay around the whole. That will help as well. Good luck!

  3. I don’t know if clay in America is different from clay in New Zealand but, after ten years planting on clay soil on a slope, I can confirm that digging is generally a mistake. It may be that if you have machinery to dig an enormous, over generous hole you can create pockets of better growing conditions – that’s the best interpretation and requires ideal soil prep – but digging is rarely ideal. Maybe on flat land it might be more valuable? So, just in case I can save someone a lot of heartache: what we’ve found to work best is to level the site so a tree cage can sit easily on the ground (on sloping ground this is a significant but not too onerous bit of digging and consistents of as much topsoil as you’re going to get). Then put on a tree cage (or just something to stop the soil rolling away in storms before the roots get into it) and plant the tree in a mound on top of that flat site with the soil you dug and any other amendments you might have (ideally good dirt, mature compost and manure, maybe even a bit of sand). Then mulch well with leaves, peastraw or whatever you have (taking care to balance it out so wood chips get extra nitrogen like blood and bone or fresh grass clippings get some dry leaves or wood chips etc). This allows the plant to make it through that crucial first stage mentioned above, not get waterlogged in winter (we plant in autumn before our wet winters) and send nutrients into the clay below slowly through worms and leaching until the roots can penetrate themselves. Digging big deep holes make planting pots in true clay, so you limit the growth to a few good years. Planting on top and then mulching means the trees get stronger and stronger with time.
    Of course, it all depends on just how clay your site is (clay loam is fine to dig). I’,Ve learned to love my clay soil but only by planting on the surface and then building the soil up so the worms make the depth, not my spade.
    Nice list. This author does know what they’re talking about. And the most important thing with clay is to have it growing something, anything, not leaving it to the sun and rain to turn to pottery 🙂

    • Oh, and evening out the soil moisture is the most important thing with clay. It’s great soil if it’s always a little moist but not too wet and not too dry and you don’t mess around crushing the soil structure too much. Dry season irrigation, mulching and improved winter drainage each make a big difference.
      My grandmother back in the 50s made 10acres some of the lushest ground around by digging a series of ponds (only way to get irrigation as they didn’t have plastic tanks), planting roses and keeping donkeys. We visited every summer and the place was deep green and lush when everywhere else was cracking up. Yes, she also grew apple trees, crab apple, plums, rhubarb, lavender, rosemary, a vege garden (silverbeet was common), and kept ducks and chickens. She grew a lot more than that but heaps of the above. Conifers can grow well but you need to be ok with all the shade and bare ground under them. Donkeys eat thistles and make manure that grows the best roses, apples, rhubarb and plums ever. And any mash you feed them helps the soil too.
      Agapanthus, hydrangeas, cape honey flower etc all grow as serious weeds here so if they’re not a problem where you are and you’re warm enough, do try them. Carex, especially Australian sedge is also a pernicious weed here but it makes lovely soil out of clay and copes with drought. Parsley is good too, especially flat parsley.
      I’ll stop flooding this page now. Please feel free to edit it down. It’s just so nice to be able to share what I’ve learned the hard way.
      Oh and of course local natives are always a good place to start.

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