If you want a fertilizer schedule to follow, I have some tips for you.
Fertilizer companies often create a schedule for you that outlines exactly when to fertilize, but that's often done to maximize their revenue, not the health of your garden.
The thing is, there's no such thing as an off-the-shelf fertilizer schedule that is right for every garden. We can, however, follow some well-established guidelines.
I tend to divide fertilizers into 2 categories: "long term soil building" and "short term plant building". Let's look at a fertilization schedule for them. It's the same for the lawn and garden...
Update: 2 years after I wrote this article, I decided to start selling a few organic fertilizers, so I'll put links to them below.
Soil building fertilizers are mostly mineral fertilizers such as calcium carbonate. You generally use them based on a soil test to balance out the ratios and percentages of specific major nutrients in your soil, such as calcium and magnesium.
The timing for your garden fertilizer schedule is that it should be done in spring or fall. Actually, it's nice to divide the application in two and do it in spring AND fall if possible.
If you go to the website of the evil Scotts fertilizer company or indeed most fertilizer companies, you can find their fertilizer schedules. They'll often have the applications divided into four times throughout the year.
This number of applications would actually be okay, IF you were doing these fertilizer applications based on a soil test.
It's not a great idea to apply the common N-P-K brands (nitrogen-phosphorus-potassium) such as 10-10-10 fertilizer 4 times per year just for good measure, but if your soil test told you that you need 40 pounds of calcium carbonate per thousand square feet in order to increase your calcium levels, then it would certainly be good to do that.
In terms of when to fertilize, I tend to split it into two applications because life gets busy, plus it's easier to apply mineral fertilizers to the vegetable garden during early spring and late fall when many of the plants aren't there.
But what to apply for long term soil building? If you haven't done a soil test, I feel okay recommending 10 pounds of calcium carbonate once per year.
Other than that, you don't want to apply concentrated forms of any nutrients without a soil test. The odds are good that you'd make things worse by applying common N-P-K fertilizers indiscriminately.
But the fertilizer companies did get one thing right. If you're using an appropriate organic fertilizer for your soil, then it's true that a fertilizer schedule of small, regular applications are better than one big dump.
These regular applications are especially useful for the more quickly available organic fertilizers you can use throughout the year.
I often call these biostimulants. Many of them are in liquid form. These are products like liquid seaweed and sea minerals that are full of tiny amounts of 70-90 different minerals, which are important for many aspects of plant growth.
They're sprayed directly onto plants and soil where they can be used right away by both plants and microorganisms. They can really improve many aspects of plant growth and nutrition. And they're important for soil life, too.
I use the lowest suggested application rate for these kinds of products, and use them on a monthly basis. You could even cut the rate lower and user them weekly.
There is good research showing that using organic fertilizers more often, in lower doses (often extremely low doses), promotes the best results.
So a solid garden and lawn fertilizing schedule looks like this:
Any questions about when to fertilize? Let me know below .