Fertilizers, Soil Amendments, and Mulches
Soil Tests: What does your soil need? What does it already have?
Organic soil modifiers (compost and such)
Our just go straight to our recommended General Fertilizer Program
Common Ground stocks a wide variety of fertilizers:
Fertilizers
| FoxFarm Planting Mix- best for starting seeds, transplants, and as a high end compost. | 1 cu. ft. |
| FoxFarm Potting Soil- very best for container gardening | 1.5 cu. ft. |
| FoxFarm Potting Soil- very best for container gardening | 12 quarts |
| Happy Frog Conditioning Compost- the finest, with worm castings, bat guano and mycorrhizae | 3 cu. ft. |
| Chicken Manure Compost | 1.5 cu. ft. |
| Cocoa Bean Hulls- great chocolate smelling mulch, repels snails and slugs | 2. cu. ft |
| Soil Building Compost | 1.5 cu. ft. |
| Straw Bales | Bale |
| Worm Castings- pure food for your healthy plants and soil | 12 qt. bags |
| Red Worms for Composting - shipped to you | 1 lb. |
Boxed and Bagged Fertilizers
| Alfalfa Meal - good balanced fertilizer | Bulk, 25 lb, 50 lb |
| Azomite- granular with minerals and trace elements | Boxed and 50 lb |
| Bat Guano- high in phosphorus | Bulk and 25 lb |
| Corn Weed Blocker- pre-emergent weed blocker and fertilizer | Boxed and 25 lb |
| Cotton Seed Meal | Boxed and 20 lb |
| Feather Meal - high slow-release nitrogen source | Boxed and 20 lb |
| Fish Meal - great source of nitrogen | Bulk and 50 lb |
| Fish Bone Meal- good phosphorus source | Boxed and 25 lb |
| Greensand - potash and breaks up heavy soil | Bulk and 25 lb |
| Kelp Meal - potash and minerals | Bulk and 20 lb |
| Oyster Shell Meal- calcium source | Bulk and 25 lb |
| Seabird Guano | 20 lb |
| Soft Rock Phosphate | Bulk, Boxed and 50 lb |
| Soy Meal - great source of nitrogen | 20 lb |
| Acid Mix | Boxed and 25 lb |
| All-Purpose | Boxed and 25 lb |
| Bio-Turf - Customer Favorite! | 25 lb |
| Rose and Flower - promotes flowering | Boxed and 25 lb |
| Vegan Mix - balance all purpose for vegetables and ornamentals | Boxed and 25 lb |
Boxed Fertilizers
| Citrus & Avocado |
| Acid mix - great for blueberries, rhubarb, rhododendrons and azaleas |
| Humic Acid Ore |
| Dolomite Lime |
| Granular Sulfur |
| Tree & Shrub Food |
| Soft Rock Phosphate - long lasting source |
| Bio Live, promotes growth of mycorrhizae |
Pound bulk fertilizers |
self serve, you bag and weigh |
| Alfalfa meal - a great source of nitrogen |
| Bat guano - high in phosphorus |
| Fish Meal - a great source nitrogen |
| Greensand - for potash and breaking up heavy soil |
| Kelp meal - for potash |
| Oyster shell meal - calcium source |
| Soft rock phosphate |
Other Fertilizers, Quarts and Gallons
Jump start your plantings and use for regular feedings. Some for indoor use as well.
| Sean's Organic Plant Fertilizer | |
| Maxicrop liquid seaweed | |
| Fox Farm Big Bloom - promotes flowering | |
| Earth Juice - Grow, Meta-K, Microblast | |
| Earth Juice - Rootstock, cutting gel | |
| Soluble Root Zone- with beneficial bacteria | 4 oz |
| Granular Root Growth Enchancer | 2 oz |
| Soluble Root Growth Enchancer | 1 lb |
| Bu's Brew Biodynamic - compost tea bags | 16 oz |
Soil Tests
Soil conditions may vary from backyard to backyard. For the most efficient and effective use of organic soil amendments, a soil test is advisable, if possible. Even a simple test using a LaMotte soil test kit can help you to judge what your soil needs for 3 key elements. If you live in the Menlo Park/Palo Alto/Mountain View area and choose not to perform a soil test or have one done for you, the recommendations on p. 4 of this leaflet can help you to estimate the amendments to apply.
If you use a LaMotte soil test kit to test your soil, you should use the amendment recommendations for N, P, and K on p. 45 of How To Grow More Vegetables.
Especially for a garden of 500 sq ft or more, it is best to have a professional soil test performed. A very good soil testing service is:
Timberleaf Soil Testing
Murrieta CA 92563
Phone/Fax (951) 677-7510
As a first step, write for free information and a sampling kit. You should have their basic and trace mineral tests performed. These will include pH, organic matter, nitrogen, phosphorus, potassium, calcium, and trace minerals. The cost for both will be about $55.00. In addition to the results, you will receive an easy-to-understand interpretation and specific recommendations for correcting deficiencies. If you are mini-farming or gardening 500 sq ft or more, the soil test should more than pay for itself due to increased yields and reduced fertilizer expenses.
A pH reading tells you the relative acidity/alkalinity of the soil. Most vegetables will grow well in a range from 6.0 to 7.0. In extremely acid or extremely alkaline soils, valuable nutrients are tied up and thus unavailable to the plants. An acid soil can be sweetened by the addition of dolomite lime.
Organic Sources of N, P, and K
N, P, and K refer to the three main nutrients plants need:
NITROGEN for green growth and in compost piles to speed
decomposition; PHOSPHORUS for energy, root growth, disease
resistance, and production of good fruits, vegetables,
flowers and seeds; and POTASH for strong stems, vigorous
roots and increased disease resistance.
| Source | Ni- tro- gen (N) | Phos- pho- rus (P) | Po- tas- sium (K) | How Long does it last? | Comments |
| Alfalfa Meal | 2-3% | 0.7% | 2.25% | 3-4 months |
A quick-acting source of nitrogen and some potash. Use up to 19 lb (163/4 qt) / 100 sq ft. |
| Phosphate Rock | --- | 33% | --- | 3-5 years |
Very slow-releasing Use up to 6 lb (22/3 qt) / 100 sq ft. |
| Soft Phosphate (Colloidal) | --- | 18% | --- | 2-3 years |
Clay base makes this phosphorus more available to plants than the phosphorus in phosphate rock, though the two are used interchangeably. Use up to 6 lb (22/3 qt) / 100 sq ft. |
| Kelp Meal | 1% | --- | 12% | 6-12 months |
Excellent source of potash, iron and other minerals. Kelp meal is also a natural fungicide. Cold-water kelp is preferable; warm-water kelp may contain toxic amounts of mercury and is not recommended. Use sparingly (1 lb [2/3 qt] / 100 sq ft) because it contains growth hormones. |
| Wood Ash | --- | --- | 1-10% | 6 months |
Ashes from wood are high in potash and help repel root maggots. Ashes also have an alkaline effect on the soil, so use them with care if your soil pH is above 6.5. Black wood ash is best. See p. 48 in How To Grow More Vegetables for more information on wood ashes. Use up to 1.5 lb (13/4 qt) / 100 sq ft. |
| Crushed Granite | --- | --- | 3-5% | Up to 10 years |
Slow-releasing source of potash and trace minerals. Use up to 8.5 lb (31/2 qt) / 100 sq ft. |
Organic Sources of Calcium
Calcium helps break up clay and release nutrients tied up in alkaline soils. It is especially good for cabbage family crops (and can help keep your tomatoes from getting blossom end rot).
|
Eggshells |
High in calcium. |
|
High-Calcium Lime (Calcite) |
A good source of calcium when magnesium levels are too high for dolomitic lime. Oyster shell flour is a good substitute. 1 qt = about 1 lb 14 oz. |
|
Dolomitic Lime |
A good source of calcium and magnesium to be used for acid soils. In a clay soil, 8.75 lb of lime per 100 sq ft raises the pH one point. In a light sandy soil, 2.5 lb per 100 sq ft raises the pH one point. Do not use in soil with a sufficient or high magnesium level. Do not use lime to "sweeten" the compost pile as doing so will result in a serious loss of nitrogen. A layer of soil will discourage flies and reduce odors. 1 qt = about 3 lb 8 oz. |
Organic Soil Modifiers
Plants also need HUMUS (with its organic matter and minerals) which is produced by decaying organic matter such as compost, manure, rice hulls and cover crops (compost crops). An alkaline soil can be brought closer to neutral by compost or manure. Compost has a buffering effect on soil, correcting both acid and alkaline conditions.
| Compost |
Good compost is the most important part of the garden. It aerates the soil, breaks up clay, improves drainage, prevents erosion, neutralizes toxins, holds precious moisture, releases essential nutrients, and feeds the microbiotic life of the soil, creating healthy conditions for natural antibiotics, worms and beneficial fungi. Use up to one inch of compost which includes 50% soil by volume (8 cu ft [12 five-gallon buckets] / 100 sq ft) per four-month growing season, or up to 1/2 inch of compost (4 cu ft [6 five-gallon buckets] / 100 sq ft) if compost is made without soil. |
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Manure Solids |
Horse |
0.7% N |
0.2% P |
0.7% K |
Age 2-3 months |
|
Rabbit |
2.4% N |
1.4% P |
0.6% K |
Age 2 months |
|
|
Chicken, Fresh |
1.5% N |
1.0% P |
0.5% K |
Age 2 months |
|
|
Chicken, Dry |
4.5% N |
3.5% P |
2.0% K |
Age 2 months |
|
|
Sheep |
1.4% N |
0.5% P |
1.2% K |
||
|
Pig, Fresh |
0.5% N |
0.3% P |
0.5% K |
||
|
Dairy Cow |
0.6% N |
0.2% P |
0.6% K |
||
|
Steer |
0.7% N |
0.5% P |
0.7% K |
Age 2 years |
|
|
Manure is a source of organic matter in the garden. Nutrient levels depend on proper handling and the amount of straw or sawdust present. Large amounts of bedding may add up to 2 years to the decomposition time. Fifty pounds of manure dry weight (approx. 2 cubic feet [3 five-gallon buckets]) applied per 100 sq ft can lower the pH one point. |
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| Gypsum |
Gypsum is not needed by organic gardeners and should be used only with the recommendation of an expert. It is normally used commercially in soils made impermeable by excess exchangeable sodium. 1 qt = about 1 lb 4 oz. |
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General Fertilizer Program Assuming No Soil Test is Performed
| Functions |
Sources Choose one for each function. |
1st & 2nd Yr Assum- ing |
3rd & 4th Yr or 1st & 2nd yr |
5th Yr or 1st yr |
Mainten- ance every year |
|
Nitrogen (2) |
Alfalfa meal (2.5% N) |
16 lb |
10.5 lb |
5 lb |
|
|
Phosphorus |
Phosphate rock |
6 lb |
3 lb |
2 lb |
|
|
Soft phosphate |
6 lb |
3 lb |
2 lb |
|
|
|
Potash & Trace Minerals |
Kelp meal
(3) |
1 lb |
1 lb |
1 lb |
0.25 lb |
|
Wood ash (4) |
2 lb |
1 lb |
1 lb |
1 lb |
|
|
Granite |
8.5 lb |
4 lb |
2.5 lb |
|
|
|
Microbiotic Life, Humus, Multiple Nutrients |
Compost |
up to 8 cu ft |
up to 8 cu ft |
up to 8 cu ft |
up to 8 cu ft |
|
Calcium |
Eggshells
(4) |
2 lb |
1 lb |
up to 1/2 lb |
up to 1/2 lb |
|
Oyster shell |
2 lb |
1 lb |
up to 1/2 lb |
up to 1/2 lb |
Add all amendments after double-digging. For the first double-dig, compost may be added before double-digging; see How To Grow More Vegetables, pp. 10-12, 14).
(1) Beginning with the 6th year, your legumes, compost crops and recycled plant material (in the form of compost) can provide most of your nitrogen, phosphorus and potash. Double-check this periodically with a soil test.
(2) Nitrogen Å (% of protein) / 6.25. The 1st & 2nd Yr amounts will provide 0.4 lb pure N / 100 sq ft.
(3) For trace minerals: kelp meal is up to 33% trace minerals. Be sure to use cold-water kelp.
(4) Save your own.
(5) Top priority in typical adobe soil. Breaks up clay, improves drainage, releases nutrients and lowers pH.
(6) This amount of compost assumes a compost recipe that results in cured compost which contains 50% soil by volume. Eight cubic feet (12 five-gallon buckets) of cured compost will provide one inch of compost for 100 sq ft. Two cubic feet will provide 1/4 inch of compost for 100 sq ft. You can substitute aged manure for compost the first year if you do not have a ready source of compost; use half the amount recommended above.
Top
Special Tips for Lawn and Fruit Trees
To revitalize an old lawn: Use 7 lb alfalfa meal, 4 lb soft phosphate, and 1 lb kelp meal per 100 sq ft. Apply in spring, and water well twice a week for 2 weeks. You should see results in 6 weeks.
Fruit trees: Use 2 heaping tablespoons alfalfa meal per foot of height, up to 4 lb soft phosphate per full-grown tree, and a light sprinkling of kelp meal (up to 1/4 lb per full-grown tree) around the drip line. Apply in spring when leaves first start to appear, and water in well. Growing compost crops around full-grown trees (keeping the crops 2 ft away from the trunk) is beneficial. Make compost without soil for fruit trees and other perennials, and use half the recommendation given in the General Fertilizer Program above.
Citrus trees: Same as fruit trees with the addition of 5 to 8 lb phosphate rock to full-grown trees once every 3 to 5 years. Line the planting hole with crushed red rock for a long-lasting source of iron.
TopSean's Organic Plant Fertilizer is the new and improved Sean's Organic Worm Fertilizer. It is a blend of compost tea, liquid worm castings, worm urine, humus tea, and more. It is perfect for all of the plants in your organic garden. We recommend that you use the fertilizer as soon as possible and apply it to your organic plants every two weeks.