Worm castings affect cucumber growth rate

A 14-day interval is ideal for applying worm castings to most vegetables. The application rate will vary based on the age of your transplant, for seedlings, 2-4 tbsp per plant is ideal to establish your garden, whereas for more established transplants as those sold in 6 oz containers apply 4-6 tbsp per plant. Each one of our units has approximately 295 tablespoons of worm casting.

A simple visual experiment assessing cucumber response to 5 tbsp vermicompost was conducted and the use of imagery was used to record plant response 12 days later.

12 days after worm casting application

The cucumber plant responded positively to worm casting treatment and visually there was an almost 300% increase in plant size. Besides available nutrients, plant growth regulating substances (PGR’s) also positively stimulate plant growth. Arancon et al. (2004) matched the nutrient content of vermicompost with synthetic fertilizer in a comparative study and observed significant growth responses that could not be attributed to the presence of macronutrients. Subsequent analysis and experiments revealed that humic acids and plant growth substances strongly influence plant growth. 

Significant levels of plant hormones such as gibberellins, cytokines, and auxins are produced during vermicomposting. The use of aqueous extracts of worm castings (worm tea) can greatly improve the availability of nutrients and beneficial substances found in worm castings to plants.

Reference (s)

Arancon, N. Q., C. A. Edwards, P. Bierman, C. Welch, and J. D. Metzger. 2004. “Influences of Vermicomposts on Field Strawberries: 1. Effects on Growth and Yields.” Bioresource Technology 93 (2): 145–53. doi:10.1016/j.biortech.2003.10.014.

Micah Martin
Micah Martin

Soil Scientist (BSc., Mphil. UWI)
Specialized earthworm taxonomy and Vermicomposting
CEO Compost-Inn


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