[tweetthis]13 Key Nutrients for Plants – #11 Calcium[/tweetthis]

Soil testing is an important activity for a successful garden. Soil stewardship is an ongoing process, where you test and amend, grow some stuff, then test, amend and grow some stuff….and so on. Focus on building soil tilth so it can really hold and make available to the plants all the important nutrients. You do this in part by adding compost, manure, rock dust, bone meal, kelp & fish emulsions. Read this article series to learn more about each of the 13 key nutrients for your garden.


Calcium is used by the plant to build the structure of cell membranes, supporting the development of cell wall rigidity. Calcium helps water penetrate the soil which helps reduce salinity and better maintain a chemical balance. Calcium is also important to neutralize acids within the cells and remove carbohydrates if unused.

Deficiencies in Calcium will appear first at the top of the plant, with the youngest leaves developing transparent white spots between the veins and along the edges of the leaves. The leaves will turn yellow between the veins, which remain green. Roots will be short and thick and have few root hairs but will be highly branched. Flowers will just fall off, and fruits fail to develop properly and lack sweetness or good taste.

To correct a deficiency of Calcium
  • to facilitate the plant absorbing Calcium make sure the pH is not too acidic
  • keep peat and manure levels low enough that they do not increase acidity
  • Add fish bone meal to add direct Calcium
    NOTE: this will add phosphorous as well

Too much Calcium in the soil can make it harder for plants to take up other nutrients, including Magnesium, Boron, Iron, Phosporous, Potassium, Zinc, Copper and Iron which can result in or worsen deficiencies in those nutrients.

To offset excessive Calcium
  • bring the other nutrients, in particualr Magnesium, into balance by adding them

[tweetthis]Do your plants need Calcium? Find out by reading this post![/tweetthis]