Growing Lilies in Clay Soil

Clay Soil: Not good for growing lilies and plants..


Growing lilies in clay soil, growing plants in clay soil can be accomplished with good results. Will lilies and other plants grow in clay? Yes, but difficult.. With shaded moist cool soil, here’s how. See how we grow lilies in clay at our annual lily festival!

Lilies grow best when basking in sunshine. But with a shaded, cool soil that is moist, crumbly and well-drained is best. Clay soils are naturally dense, compact easily and do not drain quickly, causing the bulb to rot.

What is Clay?

Clay is a finely-grained natural rock or soil material that combines one or more clay minerals with traces of metal oxides and organic matter. Clay soils are plastic due to their water content and become hard, brittle and non–plastic upon drying.
Described in various ways as adobe, gumbo, or “heavy”. And is composed of small mineral particles generally flat in shape that form a close bond with one another. Water and air have difficulty passing through tightly bonded particles.
In clay soil, oxygen is not supplied as readily to roots. And your bulbs will suffocate and rot with too much moisture. Especially true if your beds are newly planted. And worm activity has not created channels for rainfall to soak readily in the underlying soil. In addition, mixing in builder’s sand or pumus, along with only a small amount of compost. Therefore, lightening the soil evenly across the entire bed.  Likewise, above grade preventing over saturation.
Clay soil is prevalent many parts of the United States, and it can be very problematic if you are trying to grow a flower or vegetable garden. While some trees and shrubs grow well in clay, annuals, perennials, and vegetables don’t have roots strong enough to force their way through dense clay And if spring flower bulbs are your dream, forget it—most bulbs tend to rot over the winter in clay soils.
Growing lilies clay soils, as well as other plants can be improved.  However. with some background information and a well-designed strategy, you’ll be able to grow flowers and vegetables to your heart’s content.

Amend The Clay for Growing Lilies in Clay Soil

While wet (not saturated) or damp, amend and berm the clay soil before planting the lily bulbs. A light amount of compost, well rotted manure will help break down the clay.  Add plenty of pumus granules for good aeration.  However, our Power Grow Potting Mix/Soil Amendment blend is the best material to use.  Gypsum alone will help but needs to be mixed with the clay soil.

Power Grow Potting Mix
Power Grow Soil Amendment and Potting Mix

Growing Lilies in Clay Soil: How, When, Where

Growing Other Plants in Clay Soil


Choose an ideal area in the garden (such as a level grade or a gentle 5 to 10% slope) that does not tend to puddle or remain soggy after irrigation or rain. Avoid a depression or the base of a slope or hill because that’s where water will accumulate. Your planting area should receive at least four hours of uninterrupted sunlight daily. Some shading during this period is ok (such as caused from a tree limb, side of a building, other garden plants) but not too long.


Dig the soil with a shovel to create the lily planting bed. Cultivate the clay deeply, to a depth of 10 to 12 inches. It will be best to dig your spots for your lily bulbs in the Spring while the soil is wet otherwise, moisten the soil enough to make digging easier. Turn the soil, smashing and pulverizing all soil clumps…the smaller the better. Try to work so you don’t walk over the clay soil you’ve just turned over.


Water the lily bulbs as needed being careful not to over water and rotting your bulbs. Lilies do not require a lot of water, only enough to keep the soil damp. You want the amended berms of clay soil to be evenly moist, never soggy or sticky in texture. Place a 2- to 3-inch layer of mulch over the mounded soil in the lily planting bed. Mulch shades and cools the soil in summer, reduces weeds, and conserves moisture.

Organic Matter/Amendments

To Grow Lilies and other plants in clay soil:

Place 10 to 14 inches of organic matter or amendments into the freshly dug clay soil bed. And scattering it in increments of 2 to 3 inches at a time. Consequently, followed by mixing and incorporating the clay and organic matter. Mixing it with the shovel is easiest. Work the compost or well-rotted manure at least to the 8-inch depth. This organic matter improves the soil’s texture porosity and drainage. Afterward, the planting bed should be 4 to 8 inches higher than the surrounding grade.

Allow the planting bed or burm to naturally settle for a week or two before planting the lily bulbs.  Follow our planting and care directions that accompany your bulbs. Lily bulbs are planted two to three times as deep as the bulb’s height.  Subsequently 4 to 6 inches deep. Space bulbs at least 16 inches apart. Air circulation around lilies is important, especially in gardens where moisture is abundant or slow-draining clay soil dominates.

Raised Beds/Large Containers

If digging and amending clay soil sounds overwhelming or you’d rather be doing something else. Build raised beds. Or grow lilies in large containers.

  • Minimum depth should be eight inches.
  • Strong wood for frame. 2″x8″ or larger.
  • Attach 1/4 ” square contractors wire across bottom. Preventing varmits from entering and eating bulbs.
  • Use fresh potting mix with a minimum of 40% pumus for good aeration and drainage. Replace every three to five years.
  • Plant bulbs a minimum of 3 inches deep.
  • Fertilize twice yearly.
  • Keep Ph at 5.5 to 6.5.
Lilies in Raised Beds


Once fall frost kills the above ground stems, don’t worry about irrigation. Dormant lily bulbs are best left in moist to slightly dry soil in winter.

Gritty, larger-textured sand may also be added to amend the clay soil, but use it sparingly. As a matter of fact, too much sand and compost prevent good drainage. Moreover, making wet clay more like concrete once it dries.

When dealing with a lot of deep clay, try building burms to plant in. Or simply build raised beds.

Loam (a gardener’s dream) is a mixture of clay, sand, and organic materials which is fast-draining and naturally fluffy, allowing soil to stay slightly moist but not soggy between watering cycles.

Keep any mulch 2 inches away from the lily stems. This ensures good air circulation and prevents fungus or rot from occurring at the soil line on stem bases.

Test your growing medium yearly with our soil pH tester meter. Then adjust accordingly. pH level for all lilies (including Callas) should be at 5.5 to 6.5.

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