We have some family in Minnesota and they asked me how they should be fertilizing their apple trees. While I had a few ideas, I wanted to do more research to give them the best answer I could. Here’s what I found.
When fertilizing apple trees, aim for a fertilizer with a balanced NPK (nitrogen, phosphorus, and potassium—the three main nutrients for plants) such as a 10-10-10. Most fertilizers also contain sufficient secondary nutrients including iron, magnesium, and copper. Ideally, apply fertilizer once a year in the spring.
So, while using a balanced fertilizer is ideal for apple trees, what are some examples of the best fertilizers, and what are some other tips to get more fruit? Let’s take a closer look.
My Top 3 Fertilizers for Apple Trees
1. Down to Earth Fruit Tree Mix
I use Down to Earth for all of our fruit trees and I’m always happy with the results. I feed them at the start of spring, about once a year. I also provide compost and mulch as extra nutrients to help build the soil.
Down to Earth started in Oregon in the late 70s as a result of American gardeners demanding organic options to the countless synthetic fertilizers filling the shelves. They caught the market right on time to be a part of the booming organic movement in the 80s.
This fertilizer from Down to Earth has an NPK of 6-2-4, which is great for most fruit trees (especially apple trees). While the phosphorus is a bit lower at 2%, I suggest supplementing this with bone meal or wood ash if needed.
Nitrogen (N) is the primary nutrient for trees to grow foliage while phosphorus (P) and potassium (K) are used to grow flowers and fruits. Too much nitrogen discourages flowering and fruiting.
I recommend young apple trees receive more nitrogen, and mature apple trees receive a more balanced NPK fertilizer.
Down to Earth’s fertilizers are OMRI Listed (Organic Materials Review Institute), so it meets most organic standards. If growing organically is important to you, Down to Earth is a great choice.
However, I recommend double-checking the product description and their website to make sure it meets your standards, especially if you’re growing apple trees commercially.
2. Dr. Earth Organic Fruit Tree Fertilizer
When I first started caring for our fruit trees, I used Dr. Earth and I was happy with the results. Today, I prefer Down to Earth, but Dr. Earth is still a close second.
Dr. Earth first started in the gardening scene with organic fertilizers and probiotic soils in 1991. They largely source their fertilizers from food scraps from grocery stores and farms and repurpose them into fertilizer and soil.
Like Down to Earth, Dr. Earth’s fruit tree fertilizer is OMRI listed, so it’s been inspected for growing organically.
Dr. Earth’s organic fruit tree fertilizer has an NPK of 5-5-2, so it has double the nitrogen and phosphorus to potassium. Generally, this makes it slighter better for young apple trees, but mature trees can still benefit from it.
If you choose Dr. Earth, I recommend supplementing the potassium via kelp or banana peels.
3. Jobe’s Organic Fruit and Nut Tree Fertilizer
I haven’t used Jobe’s fruit tree fertilizer yet, but I hear others have had success with it, so I bought some to try it out. However, I’m a bit skeptical as Jobe’s doesn’t have the same organic listing as other fertilizers (OMRI).
I wasn’t able to locate how Jobe’s is labeled organic. However, Down to Earth and Dr. Earth are both OMRI listed for organic use.
Jobe’s fruit and nut tree fertilizer has a flipped NPK compared to other brands, with an NPK of 3-5-5. As a result, it’s ideal for mature apple trees.
In the spring, you can provide extra nitrogen to help your apple tree regrow its leaves, or if you have young apple trees.
For example, blood meal is incredibly high in nitrogen (an NPK of 12-1.5-0.5) and is great to mix with this fertilizer.
They recommend using 3 cups of fertilizer for every 1″ of the trunk’s diameter. If the tree’s trunk is larger than 3″, they suggest 9 cups per inch.
They also recommend fertilizing your apple tree every 4-8 weeks.
Compare this to Down to Earth’s recommendation of only 1-2 cups per 1″ inch of the trunk, and no more than 5 lbs a year, and Jobe’s instructions seem a bit excessive.
While Down to Earth and Dr. Earth might cost a bit more than Jobe’s, their OMRI listing and lower fertilizer instruction likely indicate their quality is higher.
You can learn more about Jobe’s Organic Fruit Fertilizer on their website.
Keep in mind, Jobe’s has a different fertilizer for potted apple trees (in a yellow pouch).
Other Options (What to Look For in Fertilizers)
If you’re not a fan of the above fertilizers, here are some tips to find a good fertilizer for your apple tree.
Look for:
- Organic – Organic fertilizers typically have higher quality ingredients, which means a healthier apple tree and more fruit. While organic fertilizers can cost slightly more, an easy way to get plenty of it is with animal manure.
- Balanced NPK – Apple trees prefer fertilizer with a balanced NPK, such as a 10-10-10. On the other hand, some fruit trees such as citrus and avocado prefer double the nitrogen to phosphorus and potassium (such as a 6-3-3).
- Slow Release – Avoid using fast-release fertilizers as they’re often too potent for apple trees and can burn their roots. This is especially true in the winter when apple trees are dormant and the nutrients sit in the soil.
- Reputable and Transparent – Today, most companies outsource their manufacturing and production to other companies, which means standards are never as good, and facilities are shared with countless other products and brands. A good example of a company that owns its process and has high standards is Down to Earth.
As with all fertilizer and soil amendments, apply them along the tree’s drip line (canopy edge) and no closer than 3 inches from the tree’s trunk.
When To Fertilize Apple Trees
The best time to fertilize apple trees is in the spring, right after your last frost. This way the apple tree gets an abundance of nutrients as it wakes from dormancy. Fertilizing too early or late typically won’t cause harm, but you’ll miss the apple tree’s prime growing time.
Generally, apple trees need fertilizer 1-2 times per year or compost every 1-2 months.
Using a quality fertilizer also means fertilizing less often.
These nutrients [from inorganic fertilizers] are in a form readily available to plants. However, since they are lost from the soil quickly, you may have to fertilize plants several times during the growing season unless you use a specially formulated, slow-release type.
Ross Penhallegon, Horticulture Extension Specialist, OSU Cooperative Extension
In other words, using organic fertilizer or a slow-release chemical fertilizer means more nutrients are used by your apple tree and not washed away or leached deeper into the soil.
Compost vs Chemical Fertilizer
| Compost | Chemical Fertilizers |
|---|---|
| Sufficient, slow-release nutrients | Potent, usually fast-release nutrients |
| Increases water retention | Creates a crusty, dry layer of soil |
| Promotes pest and disease resistance | Can harm soil life |
Plants are experts at using the sun to capture energy (sugars) and store it in the soil as humus and mulch from fallen branches and leaves. They also use sugar to exchange nutrients with beneficial soil life (such as mycorrhizal fungi) via their roots.
Mycorrhizal fungi promote many aspects of plant life, in particular improved nutrition, better growth, stress tolerance, and disease resistance.
Department of Biology, University of Fribourg, Switzerland
The problem with chemical fertilizers is that it stops this exchange as the plant has all of the nutrients it requires and no longer needs to trade the soil life. This causes the soil life to die off, along with all of its benefits such as water retention and pest and disease resistance.
So, while chemical fertilizers are often good in the short-term, they often have long-term effects.
Alternatively, compost provides sufficient nutrients, improves the soil’s water retention by 20,000 gallons per acre with every 1% increase, and promotes healthy soil life such as earthworms and mycorrhizal fungi.
Fertilizers have their place, but they should be viewed as a short-term solution, instead of the end goal.
The true end goal is to grow enough nutrients to feed your garden. After all, chemical fertilizers have only been around since 1903. Plants have been around for much, much longer and know how to make their own nutrients.
So, how do we help our plants do what they do best?
I recommend applying 2 inches of compost every 1-2 months under your apple tree’s canopy.
I also recommend adding mulch on top of your compost. Mulch provides essential benefits such as reducing evaporation, regulating soil temperature, and preventing soil erosion. 4 inches of mulch works, but you can go up to 12 inches.
Here are some of the best sources of mulch for your apple trees:
- Chop and drop nitrogen-fixing plants
- Clippings from pruning
- Raked leaves and mowed grass
Keep both compost and mulch at least 3 inches from your apple tree’s trunk to prevent mold buildup.
Homemade Apple Tree Fertilizer
Homemade apple tree fertilizer is made from everyday kitchen and yard scraps and should contain plenty of nitrogen, phosphorus, and potassium. This is often achieved by using enough “green” compostables such as grass clippings, coffee grounds, and bone meal.
While the ingredients will vary in nutrients, you can tailor your mixture to best suit the tree.
Here are some examples of kitchen and yard scraps and their primary nutrients for plants:
| Nutrient | Ingredients |
|---|---|
| Nitrogen | Coffee grounds, feathers, blood meal |
| Phosphorus | Bone meal, gelatin, leaves |
| Potassium | Banana peels, sweet potatoes, mushrooms |
| Iron | Kelp, beans, spinach |
| Calcium | Eggshells, bonemeal, molasses |
To see my complete list of food scrap ingredients and example combinations of homemade apple tree fertilizer, check out my post below.
Apple Tree Soil pH
Apple trees prefer a soil pH of 6.0 to 7.0.
Without a balanced soil pH, apple trees are unable to properly absorb nutrients from the soil. The reason why most plants like a slightly acidic soil pH is because it dissolves the nutrient solids and makes them more accessible to the plant’s finer roots.
Fourteen of the seventeen essential plant nutrients are obtained from the soil. Before a nutrient can be used by plants it must be dissolved in the soil solution. Most minerals and nutrients are more soluble or available in acid soils than in neutral or slightly alkaline soils.
Donald Bickelhaupt, SUNY College of Environmental Science and Forestry
The best ways to check your soil’s pH are with pH strips or a meter. I prefer using a pH meter since they’re easy to use and affordable. To see which pH meter I use and recommend, check out my recommended tools page.
If you find your apple tree’s soil pH is too acidic (below 6.0), apply alkaline amendments such as wood ash, biochar, or lime.
For soil that’s too alkaline (above 7.0), apply acidic amendments such as sand, peat moss, and coffee grounds.
Bonus Tips to Grow More Apples
- Mulch – Apply 4-12 inches of mulch every 3-6 months under your apple tree’s canopy. Keep it at least 3 inches away from the tree’s trunk to avoid mold. Only apply mulch if the soil is well-draining.
- Watering – Only water when the first 2-4 inches of soil is dry. I check this by pushing my finger into the soil, under the tree’s canopy.
- Pollination – Even though most fruit varieties are self-pollinating, they do best when they’re cross-pollinated. This commonly leads to larger fruits, more fruiting, and fewer fruit drop.
- Zones – For best results, grow apple trees in zones 3-8. While some varieties grow outside of these zones, many apple trees have a difficult time growing in hotter or cooler climates. To find your zone, check this map by the USDA.
Final Thoughts
Many of my permaculture clients tell me they’re frustrated that their fruit trees keep dying. They plant fruit tree after fruit tree, only for them to be replaced within a few months.
It took me a while to get it too, but once I did, it clicked.
The secret is that fruit trees are not made to be the first plants in a landscape.
Fruit trees are some of the most sensitive plants as they naturally grow after the pioneer plants have arrived (such as pine, acacia, and mesquite).
These pioneer plants are designed to grow in difficult conditions and establish the soil and canopies—dramatically helping fruit trees and other sensitive plants to grow.
This is why building healthy soil is the best and first thing to do before planting fruit trees.
We often do the opposite and plant fruit trees and then build the soil. It’s no wonder why so many of our fruit trees die on us.
So, build the soil, plant pioneers, and sit back and watch your fruit trees thrive.
To help you get started building soil, check out this super easy composting video by Growit Buildit.
