Calcium and magnesium are common inputs in many gardens. They are the building blocks and catalysts that allow plants to flourish. They can be found in the soil naturally, in many fertilizers, and in tap water. Many gardeners tend to supplement their feed regimen with extra calcium and magnesium (“cal-mag”), especially those using reverse osmosis water systems.
Calcium and magnesium are usually present in most plant nutrients. They can be combined into one bottle as a supplement, though some nutrient manufacturers will separate the two in order to provide the ability to dial in the perfect nutrient solution. The ratio of calcium to magnesium will vary and will be very specific to a particular type of plant.
Calcium and magnesium are also the most abundant minerals in tap water. The majority of the PPM, or EC reading, you obtain from a measuring device is cal-mag. The most typical form of these minerals in your untreated water is calcium carbonate and magnesium carbonate. Contrary to popular belief these forms are unusable by plants, particularly fast growing plants. The molecules of these compounds are far too large and immobile to be absorbed by the roots and transported to where the plant needs them. Relying on the cal-mag in tap water can lead to many problems for this reason.
There are many different forms of cal-mag that nutrient manufacturers use, and they base their decision on what they feel delivers the most benefits to the type of plants they have targeted. Examples of commonly used calcium and magnesium compounds include Calcium Nitrate, Calcium Carbonate, Calcium Chloride, Calcium Gluconate, Calcium Proteinate, Calcium Acetate, Magnesium Nitrate, and Magnesium Carbonate.
Beyond the various compounds of these two minerals there are chelators, which are used to make the cal-mag more readily available. There are vast differences in what manufacturers use to chelate their cal-mag. Most typical synthetic chelators are EDTA, DPTA and EDDHA and are classified as poly-amino carboxylic acids. Naturals chelates are also used and include humic and fulvic acid, organic amino acids or a microorganism based chelation process, which harnesses the power of microorganisms to “fix” plant food for easy uptake.
Calcium is used as CA2+ within plants, but how it gets into the plant is different story. Each form of calcium is absorbed into the cell at different rates and requires a different method for the cell to take it in. Each method requires more or less energy for the cell to exert to do so. Some highly chelated forms of cal-mag can enter the plant’s phospholipid membrane through osmosis. The quicker the cal-mag can be absorbed, the more efficiently the plant can make use of these compounds, thus facilitating lightning fast growth and cell division.
After having the cleanest base available you want to select cal-mag that is formulated specifically for horticulture. Look for labels that list several different sources or compounds of cal-mag and ensure that they have been chelated to make them that much more available to your plants. If growing organically, select cal-mag supplements that have been chelated naturally with amino acids or living biology. By using these highly absorbable forms of cal-mag you are helping to ensure the healthiest and quickest growing plants.
Calcium & Magnesium Supplements
Botanicare – Cal-Mag – Cal-Mag (2-0-0) is widely used to help prevent dry and withered flowers and fruits and increase water and nutrient uptake. It is a highly beneficial plant nutrient supplement to correct the inherent problem of calcium, magnesium and iron mineral deficiencies. This plant supplement is an excellent addition to your flower and vegetable fertilization routine.
Technaflora – MagiCal – MagiCal (2-0-0) is a highly enriched formulated blend of Magnesium and Calcium that promotes vigorous and healthy plant growth for both soil and soilless gardens. Incorporated in your regular feeding program MagiCal increases flower bud absorption and improves the nutritional quality of plants while reducing leaf chlorosis and deficiency related disorders such as blossom end rot, stem rot and tip burn. Improves density of fruit and production of essential oils. Highly soluble — works in conjunction with any nutrient
General Hydroponics – CaMg+ – CaMg+™ is biologically catalyzed from oyster shell, dolomite lime, and natural plant extracts. Through the use of organic compounds, CaMg+™ increases calcium and magnesium transport into the plants. This optimizes plant metabolism, enhancing growth and creating healthier flowers and fruits.
Cutting Edge Solutions – Plant Amp – Plant Amp is pure calcium, chelated with organic acids to improve plant absorption. This chelation process provides improved calcium transport into the plant body, meaning the calcium is easily assimilated by plants and transferred into cell growth. Use it in your reservoir or as a foliar spray.
Cutting Edge Solutions – Mag Amped – Mag-Amped is a pure Magnesium product, combined with an organic facilitator that helps with uptake and overall solubility. Mag-Amped contains a low molecular weight form of magnesium and as such is very easily absorbed by plants. Mag-Amped is fantastic as a foliar spray due to its low molecular weight and clean properties.