Do you really need to use chemical fertilizers on your lawn and garden?

I pointed out last week that all area lawns are now green whether or not they have been laced with chemical fertilizers. How many times do you have to prove to yourself that lawns don’t need fertilizer? Even applying organic ones may be overkill.

The reason this is so has everything to do with the soil food web which I write about all the time in my other life. Simply put, all plants attract microbes and when present, these feed the plant. They solubilize soil nutrients and feed the plant. And, as we are just now learning, some of these microbes even enter plant roots and provide nutrients from the inside.

The truth of the matter is artificial fertilizers are constructs created by a once well-intentioned industry that was created before we actually understood how plants operate. After World War II, use of these “artificial manures” expanded to lawns which had terrible soil conditions and low microbial populations. People didn’t keep compost piles and didn’t have have access to horses’ manure. There seemed to be a need for fertilizers.

We had no idea these fertilizers operate to the detriment of Mother Nature’s natural system, the soil food web. In the end, application of fertilizers reduces the impact of soil microbes and your lawn can’t green up without more fertilizers. It’s the trap Scotts and others want you to enter.

Ah, but the presence of microbes results in great, green lawns without applying fertilizers. If you are still applying fertilizers to your lawn, do yourself (and the environment) a favor and read up on the soil food web. It is time for a new Sourdough Gardening rule: Leave the clippings when you mow and mulch over leaves in the fall and lawns will only ever need water.

Why water? Those microbes travel in it. And nutrients they release are moved to roots dissolved in water. The trick is to emulate August weather and start watering very early in the season.

Of course, if you are still using chemical fertilizers, stop. Now is a good time as undoubtedly rain will keep your lawn green for the rest of the season. Meanwhile, leave the clippings after every mowing and mulch the leaves when they fall. Ample microbial life will return and you will never need fertilizers again.


So how about flower and vegetable beds? Why are you fertilizing them? Good question. You don’t need to do so. I don’t. The only things that go into our perennial beds are new plants and leaf mulch. Eight-foot ligularia, 10-foot tall Angelica, stunning peonies and so much more and all without one bit of fertilizer ever applied.

Vegetable gardens, too, are easily grown using the soil food web and not fertilizers, but you have to remember the Law of Return. Normally nutrients taken up by plants from the soil are put back when the plants dies and decay. Harvesting, however, stops parts of the plant from being returned to the soil. This is why it might make sense to use organic fertilizers when growing vegetables.

Of course, in the old days compost and manures were applied to vegetable gardens. Magazines like Rodale’s didn’t discuss it because people didn’t understand what it was, but compost supports a healthy microbial population and a good soil food web. No wonder nothing else was needed. And the same is true today.

The time to apply organic fertilizers is after the harvest. Soil microbes will have time before the hard frosts to break down lots of it and will actually continue to work all winter. By spring, your soil should be replenished.

Let me note (and why wouldn’t you!?) that more and more studies point out using chemical fertilizers changes the soil microbial populations in a negative way. These also point out the nutrient value of plants is reduced when using them. Isn’t the point of growing your own vegetables to produce healthy and nutritious fare?

My point is that it is time for all of us to reexamine the use of fertilizers. Let the soil food web rule like it used to and we won’t need them.

Jeff’s Alaska Garden Calendar:

Alaska Botanical Garden: Last Picnic in the Garden and lots more at New swag to display your pride in The Garden available at the gift shop.

Alaska Apple Tasting: Sample the many apple varieties grown locally and discover the ones that you want to grow. The Alaska Pioneer Fruit Growers Association’s (APFGA) free apple and fruit tasting, Sunday, Sept. 11, from 1–2:30 p.m., Begich Middle School All-Purpose Room.

Mushrooms: Belong in yards. Don’t despair; rejoice! They are a sign of healthy trees and shrubs. In new lawns, they help tie up the soil.

Jeff Lowenfels

Jeff Lowenfels has written a weekly gardening column for the ADN for more than 45 years. His columns won the 2022 gold medal at the Garden Communicators International conference. He is the author of a series of books on organic gardening available at Amazon and elsewhere. He co-hosts the "Teaming With Microbes" podcast.