Zelkova is generally harder than Ash. This conclusion is based on the Janka hardness test, which measures the resistance of wood to indentation. Zelkova wood typically scores around 2,300 on the Janka scale, while Ash wood scores around 1,290. This significant difference in hardness indicates that Zelkova is more durable and suitable for applications requiring greater strength and wear resistance. The higher Janka rating of Zelkova also suggests that it is less prone to dents and scratches, making it a preferred choice for furniture, flooring, and construction projects.