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.

 
 

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.

Magnesium is vital to the process of photosynthesis and is found in the enzymes of the chlorophyll molecules, giving plants their green colour. Plants require Magnesium to stabilize cell membranes as well as to metabolize carbohydrates. Magnesium is used to move phosphates within the plant. Plants deficient in Magnesium will display yellow mottling and brown spots on the lower leaves, that begins between the veins. The soil is usually not deficient and just the plant is. High Calcium or Potassium levels and low pH can interfere with a plant’s ability to absorb Magnesium.

To correct a deficiency of magnesium
  • use organic compost, both to supply Magnesium and also to enrich the soil and enhance its moisture retaining capability
  • for a fast fix mix 1 tablespoon of Epsom salts with one litre of water and spray it on the foliage, on a cloudy day to avoid burning the leaves

Plants that have Magnesium toxicity are rare and this would generally be caused by human application of high-Magnesium chemical fertilizers. Leaf margins appear scorched with a coppery colour, and the leaves are dark green; once the leaves are falling off it is probably too late to fix it. Soils high in Magnesium lose structure and become sticky when wet with a tendency to harden into a hard to till crust with greatly reduced air spaces once dried.

To offset excessive magnesium
  • increasing Calcium with crushed sea shells to bind some Magnesium
  • plant the soil in rotations containing grasses like rye
  • add composted manure