soil and fertilizer management
"The more we pour the big machines, the fuel, the pesticides, the herbicides, the fertilizer and chemicals into farming, the more we knock out the mechanism that made it all work in the first place."
- David R. Brower
- David R. Brower
introduction
When it comes to plant fertilization, it is easy to get overwhelmed with the sheer amount of options available these days. Beyond sunlight and water, plants require 17 essential nutrients to best support their growth, development, and reproductive activities. There are inorganic and organic fertilizers available for purchase, and if a more hands-on, labor-intensive approach is desired, gardeners can make their own. Organics will typically cost more than inorganics, as it is in many other product lines, but organics will contain more of the micronutrients in addition to the primary and secondary nutrients. If an inorganic fertilizer is found to be a better option, a decision still needs to be made as to whether to use a complete or single-source plant food. Whether applying inorganic or organic fertilizer, care needs to be taken and good judgement needs to be used to supply what plants actually need. Many successful gardeners use a combination of inorganic and organic with good results. Regardless of which fertilizers are applied, the most important tip is to use them efficiently to reduce cost, prevent plant injury, and halt unwanted environmental contamination.
Quick Question: What's the difference between a fertilizer and an amendment?
Whether a product is considered to be a fertilizer or an amendment is for the most part determined by its effect on plant growth. Fertilizers directly impact plant growth and development by improving the supply of available nutrients in soil. Amendments, by contrast, assist plants indirectly by improving soil's physical or chemical properties. Here are some related definitions created by the California Department of Food and Agriculture for further clarification:
Whether a product is considered to be a fertilizer or an amendment is for the most part determined by its effect on plant growth. Fertilizers directly impact plant growth and development by improving the supply of available nutrients in soil. Amendments, by contrast, assist plants indirectly by improving soil's physical or chemical properties. Here are some related definitions created by the California Department of Food and Agriculture for further clarification:
- Packaged Soil Amendment: This is any substance distributed for the purpose of promoting plant growth or improving the quality of crops by conditioning soil solely through physical means. This category includes hay, straw, peat moss, leaf mold, sand, wood products, any product or mixture of products intended for use as a potting medium, planting mix or soilless growing media, manures sold without guarantees for plant nutrients, or any other substance or product that is intended for use solely because of its physical properties.
- Natural Organic Fertilizer: Materials derived from plant or animal products containing one or more nutrients other than carbon, hydrogen, and oxygen that are essential for plant growth, and which may be subjected to biological degradation processes under normal conditions of aging, rainfall, sun curing, air drying, composting, rotting, enzymatic or anaerobic/aerobic bacterial action, or any combination of these, and which shall not be mixed with synthetic materials or changed in any physical or chemical matter from their initial state except by physical manipulations such as drying, cooking, chopping, grinding, shredding, or pelleting.
- Commercial Fertilizer: Any substance containing 5% or more of nitrogen, available phosphoric acid, or soluble potash, singly or collectively, that is distributed in California for promoting or stimulating plant growth. Commercial fertilizer includes both agricultural and specialty fertilizers.
- Specialty Fertilizer: Any packaged commercial fertilizer labeled for home gardens, lawns, shrubbery, flowers, and other similar noncommercial uses. These products may contain less than 5% nitrogen, available phosphoric acid, or soluble potash, singly or collectively, detectable by chemical methods.
California Soil Nutrients
California soils differ from others in their deficiencies and excesses of soluble plant nutrients. Nitrogen is naturally low in most soils on the west coast, and additional amounts need to be added to soils in order to support optimal plant growth. A good indicator of a nitrogen deficiency is chlorosis, or yellowing of older leaves. Phosphorus may also be low, especially in areas with highly weathered soil. In reddish soils with hardpan or claypan layers, phosphorus may be especially low. Other soils low in phosphorus may be overworked due to long-term cropping or due to alkaline soil conditions (which makes phosphorus unusable by plants). The third primary nutrient, potassium, is usually present in most California soils, and does not need to be supplemented. The three other main soil issues found in California soils are deficiencies in iron, zinc, and sulfur. Iron is most commonly found in alkaline soils when growing acid-loving plants like Azalea. Plants that are hungry for iron will exhibit symptoms such as interveinal chlorosis in younger leaves. In gardens where the surface layer of soil has been removed for construction purposes, zinc deficiency can occur. Finally, sulfur deficiency is commonly found in areas in California where rainfall is heavy or where irrigation water contains little to no sulfur.
California soils differ from others in their deficiencies and excesses of soluble plant nutrients. Nitrogen is naturally low in most soils on the west coast, and additional amounts need to be added to soils in order to support optimal plant growth. A good indicator of a nitrogen deficiency is chlorosis, or yellowing of older leaves. Phosphorus may also be low, especially in areas with highly weathered soil. In reddish soils with hardpan or claypan layers, phosphorus may be especially low. Other soils low in phosphorus may be overworked due to long-term cropping or due to alkaline soil conditions (which makes phosphorus unusable by plants). The third primary nutrient, potassium, is usually present in most California soils, and does not need to be supplemented. The three other main soil issues found in California soils are deficiencies in iron, zinc, and sulfur. Iron is most commonly found in alkaline soils when growing acid-loving plants like Azalea. Plants that are hungry for iron will exhibit symptoms such as interveinal chlorosis in younger leaves. In gardens where the surface layer of soil has been removed for construction purposes, zinc deficiency can occur. Finally, sulfur deficiency is commonly found in areas in California where rainfall is heavy or where irrigation water contains little to no sulfur.
Types of fertilizers
The following section will outline the various amendments and fertilizers that can be used to improve the nutrients in local soils. This list includes both inorganic and organic products.
Inorganic Fertilizers
The most commonly used inorganic fertilizers in California contain nitrogen as a main component, as this nutrient is lacking in many local soils.
The most commonly used inorganic fertilizers in California contain nitrogen as a main component, as this nutrient is lacking in many local soils.
Urea
Ammonium Nitrate
Ammonium Sulfate
Calcium Nitrate
Sodium Nitrate
Ammonium Phosphate (Monoammonium Phosphate)
Diammonium Phosphate
Superphosphate
Basic Slag
Rock Phosphate
Muriate of Potash
Potassium Sulfate
Potassium Nitrate
12-12-12 Fertilizers
8-16-6 Fertilizers
5-10-5 Fertilizers
Slow-Release Fertilizers
Bulky Organic Materials
Chicken Manure (Dry)
Steer Manure (Dry)
Dairy Manure (Dry)
Peanut Hulls
Sheep Manure (Fresh)
Poultry Manure (Fresh)
Horse Manure (Fresh)
Grain Straw
Seaweed (Kelp)
Cattle Manure (Fresh)
Sawdust and Wood Shavings
Organic Concentrates
Blood Meal (Dried Blood)
Hoof and Horn Meal
Fish Meal
Soybean Meal
Fish Scrap
Bone Meal
Cocoa Shell Meal
Wood Ashes
Alfalfa Meal
Alfalfa Meal is a great fertilizer for flowering plants, helping them bloom earlier and for a longer period of time. This fertilizer is made from fermented alfalfa plant seeds, is fluffy, and has a pleasant, earthy smell to it. You can find this fertilizer at any garden store, but it may be cheaper to check your nearby feed or animal store to see if they have any. When you apply this fertilizer, wear a mask as it is very powdery. Also, after using this fertilizer, transfer it to a plastic container. Mice love Alfalfa Meal, and can chew through bags that are left in storage. Using Alfalfa Meal is simple; sprinkle about two (2) cups around the bottom of shrubs, or along a line of hedges. Work the fertilizer into the soil with a rake, and then water the plants as you usually would. Application of this fertilizer should happen in the spring, when your plants begin to show new growth. Plants that bloom once only require one treatment per year, but those that bloom a few times a year can take application every six weeks. This fertilizer should not be used around the base of plants that prefer acidic soil, such as camellias or rhododendrons. |
Bat Guano
This fertilizer is fast-acting, has little odor, and can be worked into soil multiple times in the growing season. It is a soil conditioner that enriches soil and improves drainage and texture. It is also a natural fungicide. Bat Guano can be used as a top dressing, worked into the soil, or diluted in water and used with regular watering practices. It can be used fresh, or in a dried form.
Using this fertilizer is simple. You can either sprinkle it around the bottom of plants, or you can make a tea with it to water your plants with. To make this tea, put about a cup of guano into a gallon of water, and let it steep overnight. The next day, strain the tea, and water your plants!
This fertilizer is fast-acting, has little odor, and can be worked into soil multiple times in the growing season. It is a soil conditioner that enriches soil and improves drainage and texture. It is also a natural fungicide. Bat Guano can be used as a top dressing, worked into the soil, or diluted in water and used with regular watering practices. It can be used fresh, or in a dried form.
Using this fertilizer is simple. You can either sprinkle it around the bottom of plants, or you can make a tea with it to water your plants with. To make this tea, put about a cup of guano into a gallon of water, and let it steep overnight. The next day, strain the tea, and water your plants!
Blood Meal
This fertilizer is made of dried animal blood, usually cow blood. It is a nitrogen amendment that helps raise nitrogen levels in your soil, which will help your plants be lush and green. It can also help to raise the acid levels in your soil, which is helpful for plants who prefer acidic soil. This is a very concentrated form of fertilizer, so be sure to read the instructions on application before using it in your garden. Too much nitrogen can have harmful effects on your plants.
Blood meal is a great fertilizer to use in areas where the soil is consistently needing more nitrogen, like a veggie garden. A positive side effect of using blood meal is that it can be a deterrent for rodents like moles, squirrels, and deer, but it can also attract other animals, such as dogs, raccoons, and possums. This fertilizer is very common, and can be found at your local garden center.
This fertilizer is made of dried animal blood, usually cow blood. It is a nitrogen amendment that helps raise nitrogen levels in your soil, which will help your plants be lush and green. It can also help to raise the acid levels in your soil, which is helpful for plants who prefer acidic soil. This is a very concentrated form of fertilizer, so be sure to read the instructions on application before using it in your garden. Too much nitrogen can have harmful effects on your plants.
Blood meal is a great fertilizer to use in areas where the soil is consistently needing more nitrogen, like a veggie garden. A positive side effect of using blood meal is that it can be a deterrent for rodents like moles, squirrels, and deer, but it can also attract other animals, such as dogs, raccoons, and possums. This fertilizer is very common, and can be found at your local garden center.
Bone Meal
Bone Meal is made of animal bones that have been ground into a powder. It is used in the garden to increase phosphorus levels in soil, which will help your plants flower more profusely. Before using this type of fertilizer, get your soil tested! Bone Meal is far less effective if the pH of your soil is more than seven (7). Once your soil is below this pH level, you can add the fertilizer at a rate of 10 pounds per 100 square feet. Bone Meal fertilizer will continue to be effective for up to four months after application.
Note: Bone Meal can also be added to fertilizers you already have in order to balance out high nitrogen levels.
Bone Meal is made of animal bones that have been ground into a powder. It is used in the garden to increase phosphorus levels in soil, which will help your plants flower more profusely. Before using this type of fertilizer, get your soil tested! Bone Meal is far less effective if the pH of your soil is more than seven (7). Once your soil is below this pH level, you can add the fertilizer at a rate of 10 pounds per 100 square feet. Bone Meal fertilizer will continue to be effective for up to four months after application.
Note: Bone Meal can also be added to fertilizers you already have in order to balance out high nitrogen levels.
Cocoa Shells
This type of fertilizer is used like a mulch, applied on top of soil. Cocoa Shells are a byproduct of processing cocoa beans (to make yummy chocolate treats), so it is a very 'green' product to use in your garden. This type of fertilizer can keep weeds at bay, protect plants, prevent water evaporation, and smells and looks amazing! Using Cocoa Shells adds proteins and nitrogen to your soil as they decompose.
Note: If you have animals, this may not be the best fertilizer for you to use, as cocoa shells are just as dangerous for pets as chocolate is! If you do have animals at your house but would like to use this fertilizer/mulch, fence of the areas you use it in, and watch your pets closely!
This type of fertilizer is used like a mulch, applied on top of soil. Cocoa Shells are a byproduct of processing cocoa beans (to make yummy chocolate treats), so it is a very 'green' product to use in your garden. This type of fertilizer can keep weeds at bay, protect plants, prevent water evaporation, and smells and looks amazing! Using Cocoa Shells adds proteins and nitrogen to your soil as they decompose.
Note: If you have animals, this may not be the best fertilizer for you to use, as cocoa shells are just as dangerous for pets as chocolate is! If you do have animals at your house but would like to use this fertilizer/mulch, fence of the areas you use it in, and watch your pets closely!
Cottonseed Meal
This fertilizer is a byproduct of cotton harvesting and manufacturing. It is used best to add texture and aeration to soil. It can also be used to retain moisture in sandy soils. It has a slow-release time, and can therefore be used liberally without causing any issues for plants. Cottonseed Meal promotes healthy foliage, increases crop production and improves blooms.
Cottonseed Meal is a multi-use fertilizer and can therefore be used throughout the garden. It is recommended for acid-friendly plants like azaleas, rhododendrons, and camellias. Grasses, shrubs, veggies, and roses also will benefit from the use of cottonseed meal in the garden. The following are possible uses and quantities for different areas of your garden:
For Roses
Cottonseed Meal will raise the acid level of the soil slightly when used in the amount of 1 cup around the bottom of each plant. It is especially effective when used in conjunction with bone meal. Apply once in the spring, and again later in the summertime.
For Acid-Loving Plants
The goal here is to lower the pH level and increase availability of iron and magnesium. If your acid-loving plants have yellowing leaves, this could be a sign that the soil pH needs to be reduced. Mulch around the bottom of these plants with 3 inches of cottonseed hulls.
Turf
Cottonseed Meal can help you have a lawn all of your neighbors will envy! It helps with water retention and improves soil density. Apply 1-2 inches over a graded area that is going to be seeded. If the soil is very bad, use 8-10 pounds per 100 square feet. Work the amendment into the soil, and then tamp down and water well. It can also be used on established lawns as a fertilizer in the springtime in the amount of 4-5 pounds per 100 square feet. In late fall, apply 3-4 pounds of Cottonseed Meal per 100 square feet. This will encourage root development in the winter months, and come springtime, your lawn will be as lush as it was when you installed it!
New Veggie Garden
Amend your soil with 4-6 pounds Cottonseed Meal and 1-1.5 pounds garden fertilizer to each 100 square feet. It can also be applied over the top of your existing soil by putting 1-2 inches over the top, and then digging it in.
This fertilizer is a byproduct of cotton harvesting and manufacturing. It is used best to add texture and aeration to soil. It can also be used to retain moisture in sandy soils. It has a slow-release time, and can therefore be used liberally without causing any issues for plants. Cottonseed Meal promotes healthy foliage, increases crop production and improves blooms.
Cottonseed Meal is a multi-use fertilizer and can therefore be used throughout the garden. It is recommended for acid-friendly plants like azaleas, rhododendrons, and camellias. Grasses, shrubs, veggies, and roses also will benefit from the use of cottonseed meal in the garden. The following are possible uses and quantities for different areas of your garden:
For Roses
Cottonseed Meal will raise the acid level of the soil slightly when used in the amount of 1 cup around the bottom of each plant. It is especially effective when used in conjunction with bone meal. Apply once in the spring, and again later in the summertime.
For Acid-Loving Plants
The goal here is to lower the pH level and increase availability of iron and magnesium. If your acid-loving plants have yellowing leaves, this could be a sign that the soil pH needs to be reduced. Mulch around the bottom of these plants with 3 inches of cottonseed hulls.
Turf
Cottonseed Meal can help you have a lawn all of your neighbors will envy! It helps with water retention and improves soil density. Apply 1-2 inches over a graded area that is going to be seeded. If the soil is very bad, use 8-10 pounds per 100 square feet. Work the amendment into the soil, and then tamp down and water well. It can also be used on established lawns as a fertilizer in the springtime in the amount of 4-5 pounds per 100 square feet. In late fall, apply 3-4 pounds of Cottonseed Meal per 100 square feet. This will encourage root development in the winter months, and come springtime, your lawn will be as lush as it was when you installed it!
New Veggie Garden
Amend your soil with 4-6 pounds Cottonseed Meal and 1-1.5 pounds garden fertilizer to each 100 square feet. It can also be applied over the top of your existing soil by putting 1-2 inches over the top, and then digging it in.
Earth-Rite
This company makes five products for home gardeners to be used for lawn maintenance, vegetable gardens, roses, flower gardening, tree/shrub maintenance and planting, and even maintenance of ponds. The best use of this product, however, is for improving high-traffic areas of lawn and for amending clay soil. This product helps break down the structure of heavy clay soils, allowing for better drainage and root growth. A great way to use this product is to buy the hose-end attachment and apply it at double the rate for problem areas in the spring, and then again at the regular rate in the fall. As with any product, read the directions before application and you'll do just fine!
This company makes five products for home gardeners to be used for lawn maintenance, vegetable gardens, roses, flower gardening, tree/shrub maintenance and planting, and even maintenance of ponds. The best use of this product, however, is for improving high-traffic areas of lawn and for amending clay soil. This product helps break down the structure of heavy clay soils, allowing for better drainage and root growth. A great way to use this product is to buy the hose-end attachment and apply it at double the rate for problem areas in the spring, and then again at the regular rate in the fall. As with any product, read the directions before application and you'll do just fine!
Fish Meal
Fish Meal is made from dried and ground fish byproducts and supplies rich nutrients and organic matter. This fertilizer conditions soil, and breaks down gradually, which makes it a great slow-release soil amendment that can be used during planting or as a fertilizer throughout the growing season. Because of the smell that accompanies the use of this product, many people opt for less-fragrant amendments. The concentrations of nutrients vary by product, so if you choose to go this route, follow the instructions on the bag you purchase.
Fish Meal is made from dried and ground fish byproducts and supplies rich nutrients and organic matter. This fertilizer conditions soil, and breaks down gradually, which makes it a great slow-release soil amendment that can be used during planting or as a fertilizer throughout the growing season. Because of the smell that accompanies the use of this product, many people opt for less-fragrant amendments. The concentrations of nutrients vary by product, so if you choose to go this route, follow the instructions on the bag you purchase.
COMPOST _ PURCHASING _ TIPS
Greensand
This fertilizer is harvested from the ocean floor, and is widely available at nurseries across the country. Its name comes from its texture and color. Greensand fertilizers are high in glauconite, which is rich in iron, potassium, and magnesium. These components will assist in loosening soil, improving moisture retention, softening hard water, and increasing root growth rate. This option is slow-release, which does not cause plants to 'burn'. Like Earth-Rite, Greensand helps break up clay soils.
Be careful to read the ingredients as well as the instructions on the back of each product when choosing one for purchase, as some manufacturers will 'water down' their product by adding in sand, making it less effective. Generally, the product will be used by mixing two (2) cups of the product into the soil around the bottom of each plant or tree. If adding Greensand to a large area, the average rate is 50-100 pounds per 1,000 feet of soil. Apply in early spring as a soil amendment or all-purpose fertilizer.
This fertilizer is harvested from the ocean floor, and is widely available at nurseries across the country. Its name comes from its texture and color. Greensand fertilizers are high in glauconite, which is rich in iron, potassium, and magnesium. These components will assist in loosening soil, improving moisture retention, softening hard water, and increasing root growth rate. This option is slow-release, which does not cause plants to 'burn'. Like Earth-Rite, Greensand helps break up clay soils.
Be careful to read the ingredients as well as the instructions on the back of each product when choosing one for purchase, as some manufacturers will 'water down' their product by adding in sand, making it less effective. Generally, the product will be used by mixing two (2) cups of the product into the soil around the bottom of each plant or tree. If adding Greensand to a large area, the average rate is 50-100 pounds per 1,000 feet of soil. Apply in early spring as a soil amendment or all-purpose fertilizer.
Kelp Meal
This fertilizer is becoming very popular for organic farming. Kelp seaweed, pictured above, is a type of algae that is readily available worldwide and is also a renewable source of fertilizer, making it one of the greenest types of amendment. It contains micro-and macro- nutrients, and is also available for purchase in a liquid form. This type of fertilizer can be purchased online and at your local garden center. To use Kelp Meal, spread it around the base of plants, shrubs, and flowers. It can be mixed directly into the soil.
This fertilizer is becoming very popular for organic farming. Kelp seaweed, pictured above, is a type of algae that is readily available worldwide and is also a renewable source of fertilizer, making it one of the greenest types of amendment. It contains micro-and macro- nutrients, and is also available for purchase in a liquid form. This type of fertilizer can be purchased online and at your local garden center. To use Kelp Meal, spread it around the base of plants, shrubs, and flowers. It can be mixed directly into the soil.
Phosphate Rock
This fertilizer is created from mining clay deposits that contain phosphorus. There are many kinds of phosphate fertilizer, some liquid some powder, but all provide a steady supply of nutrients throughout the growing season. It is used for both flowers and vegetables. Roses especially like this fertilizer; they are able to develop a stronger root system and even more buds! When used in vegetable gardens, it is effective at keeping pests at bay and will allow for greater yields and richer flavor.
Best applied in early spring, work in 10 pounds per 100 square feet (follow instructions on your specific product). If you are a composter, phosphate rock is also beneficial when added to your pile and worked into soil as a part of your soil enrichment after plantings.
This fertilizer is created from mining clay deposits that contain phosphorus. There are many kinds of phosphate fertilizer, some liquid some powder, but all provide a steady supply of nutrients throughout the growing season. It is used for both flowers and vegetables. Roses especially like this fertilizer; they are able to develop a stronger root system and even more buds! When used in vegetable gardens, it is effective at keeping pests at bay and will allow for greater yields and richer flavor.
Best applied in early spring, work in 10 pounds per 100 square feet (follow instructions on your specific product). If you are a composter, phosphate rock is also beneficial when added to your pile and worked into soil as a part of your soil enrichment after plantings.
Worm Castings
As worms digest organic material, that material gets refined and nutrients are reduced to their most usable form. The process of making worm castings is called 'vermicomposting'! Try saying that five times fast... Adding worm castings to your garden will improve soil absorbency, introduce beneficial microbes and bacteria, and add humic acid to your soil, aiding in nutrient absorption. If you are interested in using Worm Castings in your garden, check out the chart on this web page:
As worms digest organic material, that material gets refined and nutrients are reduced to their most usable form. The process of making worm castings is called 'vermicomposting'! Try saying that five times fast... Adding worm castings to your garden will improve soil absorbency, introduce beneficial microbes and bacteria, and add humic acid to your soil, aiding in nutrient absorption. If you are interested in using Worm Castings in your garden, check out the chart on this web page:
Limestone
Limestone is a sedimentary rock composed mostly of calcium carbonate or calcium and magnesium. Powdered or Pelleted agricultural limestone is the best way to add limestone to your soil and lower pH levels.
Sulfur and Sulfates
Sulfur and sulfates are used in the garden to raise soil pH levels. The products commonly used for this purpose are aluminum sulfate, elemental sulfur and iron sulfate.
Sulfur and sulfates are used in the garden to raise soil pH levels. The products commonly used for this purpose are aluminum sulfate, elemental sulfur and iron sulfate.