Anything and everything I know about fertilizer (which isn't much), I learned from a class I took a while back. This is my simplified yet detailed description of how to fertilize for your garden; specific to the needs of Utah Valley.
- Nitrogen, Phosphorus, Potassium: each sack of fertilizer (usually written under the label) contains 3 numbers that represent the percentages of these 3 elements. They are always listed in this order. For example: 0-10-10 = 0 Nitrogen, 10 Phosphorus, 10 Potassium
- Iron, Manganese and Zinc are particularly bad in Utah Valley
- Utah county solids range from 7.5 - 10. Getting it below 7 is the goal.
Fertilizing Established Plants (Perennials):
Perennial plants are plants that do not die after each season; things like trees/shrubs/bushes (anything that has an established root system that you would not be able to till).
- You must use a soluble fertilizer; meaning it will absorb into the water and soak into the soil.
The best fertilizer for raspberries, blackberries and fruit trees:
- In a quart sized jar, measure:
1/3 Azaliafood (Miracle Gro 30-10-10) + 1/3 ammonia sulfate + 1/3 ironite
1 qt. jar should fertilize a 180 sq. foot garden
For fruit trees: every 2-3 years, switch from the Azaliafood to the Bloom Booster
(1/3 Bloom Booster (Miracle Gro 15-30-15 plus trace elements) + 1/3 ammonia sulfate + 1/3 ironite
How and when to fertilize perrenials:
- Fertilize through the snow: sprinkle fertilizer on top of the snow in late February, early March. The fertilizer will soak into the snow, and the snow will carry it deep into the soil.
- Sprinkle the fertilizer in a 4' wide "doughnut" shape around the drip line of the tree. If the tree is older, a second 4' wide doughnut shape should be sprinkled outside of the first to enable all parts of the root system to receive the fertilizer.
Fertilizing for the Garden (Annuals):
Annuals are plants that need to be planted annually, meaning they die after each season and do not contain an established root system. This includes the majority of plants in your everyday garden.
Type of fertilizer to use:
- In a quart sized jar, measure:
3 c. 16-16-8 fertilizer + 1 c. Ironite (iron, zinc, manganese and others) fertilizer
- 1 quart jar of fertilizer will be adequate for a 180 sq. foot garden
How and when to fertilize:
- The most important time to fertilize your garden is right before you plant
- Just before planting, incorporate the above mixed fertilizer into the soil by tilling.
This fertilizer isn't soluble (which means it wont dissolve into the water and then be carried into the soil). Sprinkling it on top of the soil without incorporating it will do nothing.
- For most plants this is the only fertilizing you will need
- Continue this fertilizing process each year.
Lowering the pH level:
Because UT soil is so alkaline, you need to try to lower the pH level. This is done best by adding sulfur.
To do so, incorporate the following into your soil along with the above mentioned fertilizer.
- 2 quarts of sulfur
- Sprinkle all 3 quarts (1 qt. fertilizer + 2 qt. sulfur) evenly over entire surface of garden
- (2 quarts of sulfur will accommodate a 180 sq. foot garden)
- Incorporate into the soil by tilling. This is not soluble, so sprinkling it on top of the soil without incorporating it will do nothing.
This much sulfur does not need to be added each year.
- On average, you can 1/2 the amount of sulfur you added the previous year
- Each year the amount of sulfur you add to your garden should decrease, but you will always need to continue to add some each year because the pH of the water we use is around an 8, which increases the alkalinity of the soil.
When testing sulfur pellets
- The best sulfur pellets should break down asap:
- place pellets into a beaker of water
- stir them every 15 minutes or so
- the pellets should turn to 'mush' in water in about 30 minutes
- Micro-go soluble: helps the plants roots absorb necessary nutrients: some plants cannot survive without it.
- This is not necessarily a necessity for plants, but it can be very beneficial for plant production
- Mix with water in a spray bottle: break up dirt and spray on the roots of plants and partly up the stem before planting them, or
- Put some in a bag with plant seeds and shake; coating them.
- When using leaves in the garden: go over them with the lawn mower first; chopping them up makes them easier to decompose
- If you are having a deficiency problem with Iron, Zinc or Manganese: you treat the plant for deficiencies in all 3, rather than the individual element
- Ammonium Sulfate is the best nitrogen fertilizer for our area
- Liquid Iron is the only recommended liquid fertilizer
- Sulfur is the best way to lower the acidic level of your soil
- Phosphorus levels in soil are usually deficient enough to add each year
Fertilizers to Avoid:
- Do not use steer manure. The food content for these cows contains a lot of salt, which is bad for your plants. Dairy cows have a better diet, which results in better manure for your garden.
- Never use Redwood or Cedar compost. It does not break down like other woods and it is toxic.
- Do not use ashes for fertilizer. Ashes will raise the acidic level of the soil, and in our area you want to lower it.
- Weed and Feed fertilizer is good for your grass, but not good for the garden. If you use this on your grass, do not use the clippings in your garden.