Organic Gardening – Foliar Feeding

       

 

Healthy well-balanced organic soil goes a long way toward giving you great plants but keeping the soil balanced to where plants get all of the various nutrients need during all phases of growth very difficult.  Plants go through various stages of growth and the amount of various nutrients needed during these stages will vary widely. The healthiest of soils, plant roots and soil biology cannot make the adjustments necessary in a time frame needed to deliver everything the plant needs.

 

Foliar feeding can take up this slack. It is an effective way to get almost instant results, it giving the plant what it needs when in needs it. This means healthy plants that are even more resistant to insects and diseases.

Foliar feeding can work in two ways depending on what you use in your feeding program:

First, is used as a nutrient spray that passes into the leaves to provide nutrients to the plant. It can be from 8 to 20 times more efficient than soil feeding if done properly, and in many cases, you will see a change within hours.  

Second, if you are including beneficial biology in your spray mixtures to help colonize leaves it can help prevent disease and control many types of harmful insects.

 

Feeding leaves nutrients: Your spray will enter leaves through openings in the leaf surface called the stomata. Stomata are a pore (or opening) in all above-ground parts of plants including the petals of flowers, petioles, soft herbaceous stems and leaves. Their main function is to allow gases such as carbon dioxide, water vapor and oxygen to move rapidly into and out of the leaf. Stomata are formed by two guard cells that regulate the opening and closing of the pore. Generally, many more stomata are on the bottom of a leaf than on the top. Normally stomata open when light strikes the leaf in the morning and close during the night. They will close during the day when the amount of water coming up from the roots is insufficient to cover the water being lost through the stomata. Because these openings do close up as the temperature increases you need to spray in the early morning or late evening when temperatures are lower and plants are most active.

Foliar spraying of plants at times of growth spurts where shortages of nutrients can show up can do wonders. Other times when nutrient deficiencies can show up such as zinc and iron which are difficult to get from roots in adequate quantities. In times of plant stress such as extended dry periods when root feeding cannot keep up. Foliar spraying is said to give plants a boost that will cause nutrient movement from the roots into the leaves for processing.

 

Furnishing beneficial biology:  Bacterial diseases on leaves are difficult to control in that they can spread rapidly if healthy leaf biology has been depleted. Chemical pesticides and antibiotics have been used for control disease control but have proven undependable and can be harmful to both you and the environment.

 

  

 

 

 

(a) healthy leaf surface colonized by beneficial organisms.  

(b)  leaf surface with active disease sites and few organisms

(Ingham, 2008).

 

Leaf surfaces have a rich microbial population which helps protects the leaf, and thus the plant, from infection, attacks by pathogenic organisms and they work with plants to protect from weather related problems. When the colonies of beneficial organisms present on the leaf surface are reduced by pesticides, other harmful chemicals or from environmental damage it exposes leaf surface infestation of harmful insects and other organisms.

When bacterial diseases get started they are difficult to control by chemical sprays like copper and antibiotics. Both are undependable and may have harmful consequences to the environment. Keeping normal levels of natural biology on the leaves can prevent or minimize bacterial diseases. Interactions between plants and beneficial bacteria can have a major effect on crop health and yield and soil quality. These microorganisms can sensitize plant cell metabolism. When plants with beneficial organisms  on their leaves are exposed to stress the sensitized plants are able to respond rapidly and efficiently.  The mechanisms by which beneficial microbes on the phyllosphere (Leaf Surface) support plant growth and health include; increasing nutrient availability; activating plant defense mechanisms; producing antibiotics; out competing pathogens; and providing growth-stimulating substances or enzymes.

If you colonize beneficial micro-organisms on leaf surfaces and into the root zone, the bad microbes have literally no place to live and grow.

Compost teas have shown very impressive disease suppression in trials conducted at Oregon state, Arizona state and Cornell University. Benefits of a “good” fungal colonization are the suppression of powdery mildew, downey mildew, snow mold, red thread, fairy ring, brown patch and summer patch. Care should be taken on using home made teas on eatable produce in that there may be harmful bacteria in the brew.

See:  http://www.puyallup.wsu.edu/~linda%20chalker-scott/horticultural%20myths_files/Myths/magazine%20pdfs/CompostTea.pdf

 

Basics for Foliar Feeding:

Temperature — Plants will close most of the stomata openings or curl the leaf at 87 F. This is done naturally so a plant does not transpire much water during the heat of the day. Most people choose to foliar feed  in the very early morning or late evening when conditions are coolest. You should try to avoid using a foliar spray if the temperature is over seventy-five degrees Fahrenheit.

Humidity - High humidity levels help overcome leaf curling and stomata closing. With the stomata closed very few nutrients are assimilated into the plant. Do not spray during or just before rain so the material does not get washed away.

 Water – Water quality is important. If you are using water from a source that has chlorine in it put the water in an open container and let it sit for 12 hours so the chlorine will dissipate. Well water needs to be checked to make sure its pH is in a range from 5.8 to 6.8, if not you need to add either an acidic product to bring the pH down or an alkaline product to bring it up into this range. With rain water make sure the surfaces that you are collecting it from do not add harmful elements. Rain water from copper roofs or wood roofs where the shingles were treated with copper.  There is a worry about harmful bacteria in some water sources; in these cases a little hydrogen peroxide is effective. Get a good pH meter and check your water and the final solution every time you get ready to spray.

Salt Index — Spray solutions should have a salt index of 10 or less. Application of IFA low salt index products will result in an osmotic absorption, which is quick, clean and complete absorption of nutrients into plant tissue without tissue damage.

Application methods – You want to use as fine a mist as you can. If you are working with a small number of plants a common quart spray bottle will work. For larger number of plants a hand held pump sprayer is useful and for large amounts of plant a backpack sprayers is great. Leaves are able to absorb the nutrients through the stomata, or pores, which cover each leaf. The majority of these are on the underside of the leaf. To ensure your best absorption of your spray, completely cover the leaves, both top and bottom.

pH Balance - Much like your nutrient solution, the pH of your foliar spray should be slightly acidic, with a pH of around 6.0. This will allow the solution to penetrate the film on the leaf and be absorbed easily into the leaf. Using a good quality water pH meter measure your pH and make any adjustments necessary with a water pH meter. Gardening supply  stores usually sell pH-adjusting chemicals by the generic names pH up and pH down. .

A supplement, not a substitute – Remember that foliar is very useful, but cannot replace healthy soil and roots. A plant’s roots purpose is to supply large amounts of nutrients which you cannot get through foliar feeding. Foliar feeding can do the following:

 Provide nutrients after transplanting. Until new roots are formed, the plant is completely dependent upon stored nutrients to maintain itself,  but foliar feeding can minimize the shock and keep the plant growing.

 Cold soil in early spring growth can be limit perennials, even when the air is warm.  Soil microorganisms are not capable of  converting nutrients into forms available for roots to absorb. Foliar feeding can quickly provide the needed nutrients to the plants, thus allowing the plant to begin growth before roots can furnish needed nutrients from the soil.

 Provide peak need feeding when the plant can demand nutrients faster than the roots can furnish them. Foliar feeding can influence flowering, fruit set, fruit size, amount of vegetative growth, among other things.

 Allows flexibility in supplying nutrients. Small imbalances in the soil can lock up various nutrients, foliar feeding allows the ability to correct these problems. Iron is in most soils but is very hard to get into a form plants can use.

 Can provide nutrients during times of plant stress. It can protect plants from the damage of weather extremes and drought.

 Help provide disease and insect protection.

 Some plants, such as azaleas, rhododendrons, camellias, and blueberries, thrive in low pH conditions so they can not extract iron unless the soil is quite acidic (5.0 or less) and may need a foliar spray boost even in slightly acidic soil.

 

Brix Scale growing – ( http://www.tandjenterprises.com/brix_equals_quality.htm ) This is where growers are trying to get the best quality end product possible. The higher the Brix Scale reading the higher the quality of the product. The higher the Brix Scale number is for what you r growing the lest problem you are going to have with disease and harmful insects.  California wine growers have been using this method for years to know what they needed to add to the vines to get the best grapes.

 

Foliar Sprays:

There is no one singular foliar spray mixture that is going to give you what you need at all times. It depends on what you are trying to accomplish and where in the growing cycle the plant is along with what is locked up in the soil at the time.  

 

A partial list of what can be used:

 N-P-K – any water soluble fertilizer can be used but be careful to use very small amount to keep salt concentrations low and prevent to burning. Things like fish hydrolysates, alfalfa pellet tea, Blood meal, bone meal and others.

 Trace Nutrients and Biology - Complete Humates, Compost tea, Worm Tea, Seaweed and others.

 Molasses.

 Herbal extracts from plants – Cyan pepper, garlic, stinging nettles, yarrow tops, chamomile, oak bark, valerian and others

 Apple cider.

 Superthrive.

 Sticker/Spreader – these help hold your spray to the leaves and spreads it over more of the leaf surface. Biodegradable vegetable oil such as Dr. Bonner’s soap or a fish oil product. Use these with care because some can damage leaf biology.

 Yucca extract

 Citrus oil

 This is just a small sampling of what is used in foliar sprays.

 

FOLIAR SPRAY All Purpose

Ingredients:

1 Tablespoon liquid Humic Acid. Recommend a complete natural Humate such as Turf & Garden Pro (www.turfprousa.com ). Be sure of country of origin on Humates. Many come from countries where quality can be suspect.

1 Tablespoon Liquid Fish. Recommend a fish hydrolysate such as Mega Green ( www.multibloom.com/  ). We recommend fish hydrolysates over fish emulsions.

1 Tablespoon Liquid Seaweed. Recommend North Sea products such as Maxicorp Seaweed. (www.maxicrop.co.uk/ )

1 Teaspoon Blackstrap Molasses

1 Teaspoon Apple Cider Vinegar

1 Gal. Water - Shake well! (If you are on city water let it sit outside in an open container for a day to naturally de-chlorinate – better yet use rain water.)  Use this to build up cold and heat resistance for all your plants plus adding to the plants growth.

 

Summery: Foliar feeding is a great tool to increase plant health and help produce a quality end product whether it be great produce, magnificent flowers or a great looking turf.

 

If you have any questions please contact jloepp@turfprousa.com  or call (407)340-7639

On-line sales contact www.ecofriendlyonline.com or call (407) 963-6001

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