Minerals That Plants Need

Minerals that Plants Need

These minerals are found in plant compost like the stuff you're making in your backyard!

Nitrogen

Nitrogen is required for all phases of growth and development in plants.  It is the primary component of protein and amino acids.

There are 2 different types of nitrogen that plants need at different times: Nitrate (NO3) and Ammonia (NH4).  Plants need Nitrate in the growth stage, and Ammonia in the fruiting stage.  If you give a tomato nitrate while fruiting, it will go back to growing and stop fruiting.  If your soil has a good balance of nutrients in it, it will switch to ammonia on it's own when it needs it.  Conversely, if you give lettuce ammonia, it will bolt and focus on seeding.

Deficiency:  Lower leaves are light green or yellowish, or plant is stunted

Heavy nitrogen feeders:

Roses
Corn
Lettuce
Tomatoes
Squash
Melons
Cucumbers
Cabbage

Organic Sources:

Blood Meal
Fish Meal
Composted Chicken Manure
Chicken Feather Meal
Bat and Bird Guano
Planted pea and bean plants
Crab Meal
Alfalfa Meal
Rain Water
Some cover crops like Hairy Vetch and Clover, but these need to be tilled in.
Rabbit Manure

Phosphorus (Potash)

Performs the energy transformation in photosynthesis to produce sugars, starches and proteins.  Contributes to cold-hardiness and root development.

Deficiency:  Lower leaves spotted, mottled or curled, underdeveloped roots, stem tissue may appear weak.

Organic Sources:
Bone Meal
Fish Meal

Potassium

Strengthens stems, helps in resistance to pests and diseases as well as fruiting and flowering.

Deficiency:  Lower leaves and stem are reddish, upper leaves are dull/ pale, failure to flower or produce fruit.
Excess: Black spots on leaves

Organic Sources:

Kelp (Seaweed)
Greensand
Composted Manure
Wood Ashes
Pecan Hulls

Calcium

Required for cell growth and division, helps plants use Nitrogen.  Blossom end rot on peppers and tomatoes is caused by a calcium deficiency.  Calcium is leached out of the soil by rain, so you may need to supplement calcium if there is a lot of rain.  This is because soil uses up it’s calcium to neutralize the acid rain.  If your healthy soil is deep, it will retain nitrogen and sulfur which combined, can also neutralize the acid and the soil can retain calcium.  So, if your soil has a healthy amount of all of the nutrients it needs, more of all of your nutrients will be retained in it.*

Calcium breaks up soil structure and helps to loosen compacted soil.  If you add too much calcium your soil could loose all structure.

Deficiency – Tipburn on lettuce, blossom-end rot on peppers and tomatoes.

Organic Sources:
Bone Meal
Gypsum
Lime

Magnesium

Constituent of chlorophyll, required for enzyme action.

Deficiency:  Whitish patches appear first on older leaves, between leaf veins.

Organic Sources:

Epsom Salts

Sulfur

Constituent of protein and certain vitamin complexes

Deficiency:  New leaves are yellowish

Organic Sources:

Composted Manure

Growth Enhancers

Sometimes, the nutrients are in your soil, but your plants need help absorbing them.

Organic Sources:

Kelp (extract or meal) in the soil, once a month for the first 4-5 months of the growing season.
Mycorrhizal Fungi – see http://www.organicgardening.com/learn-and-grow/garden-s-homegrown-ally for information on how to encourage the growth of this symbiotic fungi that helps plants absorb nutrients.

Foliar Sprays

These are nutrient rich sprays that are absorbed through the leaf pores, they give plants and extra boost and helps them to absorb nutrients.

Organic Sources:

Liquid Kelp
Compost Tea

* If your soil becomes too acid and the pH dips to 5 or less, aluminum ions are dissolved into the water and become toxic to plants.  Aluminum ions cause a stunting of the root growth and prevent the roots from taking up calcium.  It also reduces populations of microorganisms which break down things in your soil, which releases all of the nutrients above that you need.  So, if you keep your soil well stocked with the nutrients it needs, it will manage the balance it needs.   

Note – crop rotation helps balance your nutrients as well as a natural pest and disease control.  To take advantage of the nitrogen in peas and beans, plant a heavy feeder the next season.  To control for pests and diseases, you shouldn’t replant the same family in the same spot for 3-7 years depending on the life span of what you are trying to eliminate.  Create the longest rotation you can with a minimum of 3 years, more than 7 is not necessary, and most are controlled with 4 years.

In looking for organic nutrients, look for descriptive words like: natural organic, slow release and low analysis.  Beware a NPK (nitrogen-phosphorus-potassium) total that is 15 or higher.