Soil Ribbon Test: Find Your Soil Texture by Feel

The soil texture by feel flow chart

Colorado State University Extension’s flowchart asks three questions: does the moist soil hold a ball, does it form a ribbon, and how does a wet pinch feel^[1]?

• No ball → sand
• Ball but no ribbon → loamy sand

What you’re feeling for

• Sand, silt and clay each feel different: sand feels gritty, silt feels smooth, and clay feels sticky^[1].
• The ball squeeze helps too: coarse soils (sand, loamy sand) break apart with slight pressure; medium soils (sandy loams, silt loams) hold together but change shape easily; fine soils (clays and clay loams) resist breaking^[1].

How to make a good ribbon

• Get the moisture right: add water a little at a time and knead until it feels like moist putty^[1].
• Push the soil out evenly between thumb and forefinger so the ribbon keeps the same thickness and width^[1].
• Let it extend over your finger until it breaks under its own weight, then measure it^[1].
• For the feel step, wet a separate pinch and rub it between thumb and forefinger.

What ribbon length means

Longer ribbons mean more clay. Under 1 inch puts you among the loams (sandy loam, loam, silt loam); 1 to 2 inches among the clay loams; 2 inches or more among the clays^[1]. Clay matters early: Colorado State notes that a soil with only 20% clay behaves as a sticky, gummy clayey soil^[1]. For a sense of the numbers behind a name, Colorado State’s example of a sandy clay loam is 30% clay, 50% sand and 20% silt^[1].

1 inch and 2 inches (2.5 and 5 cm): the two ribbon lengths that separate loams, clay loams and clays^[1].

Coarse, medium or fine

If you only need to know whether a soil will act sandy or clayey, Colorado State gives a shorter reading of the same two clues^[1]:

• A ribbon under 1 inch that feels gritty: coarse, sandy soil.
• A ribbon under 1 inch that doesn’t feel gritty: medium texture, high in silt.
• A ribbon of 1 to 2 inches that feels gritty: medium texture.
• A ribbon of 1 to 2 inches that doesn’t feel gritty: fine texture.
• A ribbon over 2 inches: fine, clayey soil.

A sandy result points to improving sandy soil. A clayey one points to amending clay soil: clay holds nutrients well because of its negative charge and large surface area, but it packs down if it’s worked wet^[2].

The same squeeze tells you when a bed is ready to dig. Purdue’s test: if a trowelful crumbles, the soil is ready; if it forms a muddy ball, wait a few days^[3]. More in our guide to improving garden soil.

Worked example

Your soil holds a ball, ribbons to about 1.5 inches before breaking, and a wet pinch feels very gritty. On Colorado State’s flowchart, a 1 to 2 inch ribbon that feels very gritty is sandy clay loam^[1].

Texture by feel vs moisture by feel

USDA’s irrigation handbook describes a different feel test, which estimates how much available water a soil holds by comparing how a sample feels and looks with a table or a guide^[4]. That test is about moisture, for deciding when to irrigate; the ribbon test is about texture. To measure moisture by weight instead, use the soil moisture content calculator.

How accurate is the feel method?

It places a soil in a class from how it feels; it doesn’t measure percentages. A jar test gives estimated percentages, and a soil lab’s particle-size test reports the sand, silt and clay with the USDA class^[5].

Ways people use the ribbon test

• A quick check before digging a new bed.
• Checking delivered topsoil on the spot.
• Classroom and field labs practicing the feel method.
• Comparing your yard with USDA’s mapped soil for your address.

How we calculate this

The questions follow the texture-by-feel flowchart in Colorado State University Extension’s GardenNotes #214^[1]. K-State Research and Extension publishes a texture-by-feel flowchart as MF2852, based on Steve Thien’s 1979 flow diagram for teaching texture by feel^[6]. Each answer path ends in a USDA texture class, and we highlight that whole class region on the triangle, because feel can’t place an exact point.

Frequently asked questions