When your plants look wilted, discolored, or otherwise unhealthy, is your first impulse to reach for a traditional fertilizer? For your plants’ health, you might want to rethink that first impulse. Traditional fertilizers can give your plants an immediate boost, but in the long term, these fertilizers can be very harmful. They offer short-term gain, but inflict long-term pain.
What is traditional fertilizer?
Traditional fertilizers consist of mostly nitrogen, phosphorus, and potassium. These are also known as NPK fertilizers.
Why are traditional fertilizers harmful?
Contrary to popular belief, these fertilizers often harm your plants. Phosphorus, for example, damages the essential relationship between a plant and its mycorrhizal fungi. NPK fertilizers compromise trees’ root systems, block the uptake of micronutrients, encourage attack from harmful pests, and cause a host of other issues for plants. They also pollute waterways.
Traditional fertilizers can be harmful even when labeled “organic” or “slow-release.” These often have the same negative impact on plants and the environment as do traditional NPK fertilizers.
If I can’t use fertilizer, how should I feed my plants?
You’ll hear us say time and again that healthy soil is the foundation for healthy plants. Increasing the health of your soil biology (i.e., all of the life that exists in soil) greatly improves the health of your soil. To increase the health of your soil biology, add organic matter. Examples of organic matter include compost, wood chips, leaf mulch, grass clippings, and cow manure.
The change you will see with this approach is gradual (no instantaneous boosts to plant growth as you might see with NPK fertilizers), but if you build a solid foundation then your plants will thrive in the long-term.
There are other key factors to think about when you’re improving the health of your soil. These include avoiding herbicides, mosquito sprays, and soil compaction.
What is the fundamental difference between traditional fertilizer and organic matter?
Put simply, it’s biology versus chemistry. Traditional fertilizer only addresses the chemistry of the soil. Enhancing life in your soil, however, goes far beyond adding chemicals.
Healthy soil has many components. In the urban landscape, the missing component is usually healthy biology. Traditional fertilizers focus on the chemistry of the soil, which is rarely the issue.
Are there alternative types of fertilizer that are good for my trees?
Not all fertilizers are created equal. There are some great products out there, but they focus on enhancing soil biology versus simply inputting chemicals. Look for products that have the following:
- Low to no nitrogen
- No phosphorus
- Mostly organic matter (i.e., cow manure, or plant material like kelp or yucca)
- Beneficial fungi
- Beneficial bacteria
You don’t have to buy a brand name mixture to ensure that you have healthy plants. Think about it this way: organic matter is food for your soil biology. In the same way that you don’t want to eat high-fructose corn syrup, yellow #5, or refined flour, you also don’t want to feed your soil chemicals. Choose organic matter instead. If your soil is healthy, your plants will follow suit.
If you want your plants to be sustainable and thrive long-term, resist the short-term gain of chemicals and focus on increasing the health of soil biology instead. If the biology of the soil is healthy, the soil will provide all of the nutrients your trees and shrubs need. You’ll never need to think about traditional fertilizers again.