Garden Fertilizer Tips - How And When To Fertilize (2024)

Today I continue with the garden fertilizer tips.

Last week, I outlined a basic fertilizer schedule and received a couple of comments from people who disagreed with my suggestions, so I thought I’d address their concerns here in more detail.

I always appreciate any feedback people have to give, even when it runs counter to my advice. Some great learning opportunities come when we have these discussions.

Garden Fertilizer Tips – My Answers

Various comments are in italics below.

Comment: Lime is not a good idea! Many of us have alkaline soil to begin with! My dad once took the recommendation of his buddies and applied lime to my mother’s vegetable garden (it was the only thing he did in the garden since turning up the sod). That great little veggie patch turned into an unproductive wasteland. A rule that is generally used for pruning should be used for fertilizers, too: if you don’t know why you are doing it… DON’T.

Phil: That is an excellent rule. The soil is a fragile environment and we can cause real damage by using the wrong materials. One of the important garden fertilizer tips I often repeat is to avoid using mineral fertilizers without a soil test – except calcitic lime, which is calcium carbonate. I absolutely do not recommend dolomite lime – that’s where the problems come in. And I don’t recommend a big application of calcitic lime without doing a soil test first – only 10 pounds per 1000 square feet, not 50-200 pounds as the labels recommend. Actually, even one of my favorite organic soil labs – Crop Services International – has recommended 50 pounds without a soil test. But I stick with 10 pounds, which is just a light dusting that you’ll barely be able to see after doing it. Probably at least 95% of soils will benefit from this. Also, calcium does not necessarily increase alkalinity.

No, Calcium does increase alkalinity.

You’re right that calcium does usually increase pH, but on high pH soils, it sometimes lowers pH, when the high pH is due to nutrients other than calcium, such as magnesium or potassium – it just goes to show that soil is a mysterious environment.

Spraying the leaves is another NO NO. Plants transpire 24 hours a day. When you spray crap on the leaves you are force feeding the plants. Not a good idea!

I’ve never come across any negatives to foliar feeding other than the fact that occasionally the benefits are negligible. All of my favorite ecological farming consultants are recommending it as one of the most important garden fertilizer tips for improving crop nutrition.

Plants are a little like us – we eat some foods even if we don’t need them. Plants are the same – they will uptake good and bad.

Actually, they can choose what they need for some nutrients, but it’s true, for others they will take all they can get. That’s why our goal is to spray just tiny amounts of a broad spectrum of beneficial nutrients in their natural form (e.g. sea minerals and kelp), and we stay away from toxins.

Plants never uptake nutrients at night. At night they only uptake water. If you must feed plants – and I do say if you must – ONLY feed plants in the morning.

Plants do take up nutrients at night – foliar fertilizing in the evening can be very useful. But yes, I like morning fertilizing, too, and that’s when I often tend to do it.

As they say in all bird sanctuaries, don’t feed the birds, because it is not good for them. The same applies to ALL plant life.

I don’t like seeing people feeding foods like bread to birds, either, but that’s because we know this causes problems. It’s true that even bird feeders have some downsides. But with a garden, especially a vegetable garden, we’re trying to grow food plants that probably wouldn’t grow there otherwise, and we’re often doing it on very degraded soils. If we want those plants to be pest free, and if our goal is growing nutrient dense food, we often need to help out a little bit by supplementing nutrients, organic matter, microorganisms and water.

If you set up your garden properly you don’t need all the other bits of rubbish from the shops. We only started using all this rubbish in the last 60 odd years or so. The soil food web has been on the decline ever since.

I agree. Chemical use has drastically increased in the last 60 years, threatening the entire planet. But using materials like fish, kelp and rock dust as organic fertilizers has been done for centuries, even millennia. Now we’re lucky that we can get them in a bottle (although there are potential sustainability issues with some of this, too). I agree that we want to use external inputs as little as possible, and I agree that it can be possible to grow a successful organic garden without them. But using a few of them, especially early on in a garden’s life, is often very helpful to speed up the process of soil balancing that nature would otherwise take hundreds of years to accomplish. It helps us to quickly get the nutrient-density back into our vegetables that we so desperately need.

Do you have a sources page where this “good research” is. I am using your website as a starting point for my thesis research into soil amendments and sustainable agriculture (this was in response to my statement, “there is good research showing that using organic fertilizers more often, in lower doses (often extremely low doses), promotes the best results.”

One of my favorites is Roland Bunch’s summary of some of the work by Brazilian soil scientist Ana Primavesi: Nutrient Quantity vs. Nutrient Access. Everyone should download this for reading on a rainy day.

Any questions about these garden fertilizer tips or other fertilizing methods? Feel free to ask below.

And here’s my main fertilizing page.