The Dirt on Dirt

Let's talk about your garden soil. You can't grow healthy plants unless you've got healthy soil, and there's more to it than haphazardly adding a bag of fertilizer or some half-baked compost. I'm going to walk you through the basics of garden soil management from soil testing to fertilizers to crop rotation to cover crops to composting. It's a lot to talk about, so I'm going to break it down into a few parts.

So let's dive in! First up, soil tests. 

If you're serious about growing anything, you need to get a soil test. If you don't know what's in your soil, you're flying blind. Your local agricultural extension office should be able to provide you with a small box for gathering your soil sample along with written instructions. (If you don't know what an extension office is, Google your county name and "agricultural extension." A wealth of knowledge is available to you there!) You'll probably have to mail your sample box into a lab specified in the test directions, along with a check for the test fee. They usually cost in the ballpark of $10. You'll want to gather your test sample when the soil is dry and before you add any fertilizers to your soil. Fall is the best time to get a test, but any time is better than no time. 

There are definitely soil tests that are better than others, but your basic soil test should show you your pH and nutrient levels. If you can get one that shows you your level of organic matter, that's even better! The soil tests will come with recommendations about what kinds of amendments to apply and at which rates in order to achieve optimum nutrient levels. 

So, let's say you've gotten your soil test back, and it has the recommendations for how much of each nutrient you need to add to your soil. How do you know how much fertilizer to apply? Well, you could get out your pencil and paper and practice your basic arithmetic, but I love a shortcut. This calculator from Texas A&M is great. You can enter the numbers from your soil test that show how many parts per million of each nutrient is present in your soil. You'll also enter the numbers from the fertilizer grade of your preferred fertilizer. (The grade is the numbers that you find on the front of your fertilizer bag. It might say "4-3-4" or "20-20-20." Those numbers indicate how much nitrogen, phosphorus, and potassium is in the mix.) The calculator tells you how much of your specific fertilizer to apply per 1000 square feet.

Your animals will thank you for using animal-safe fertilizers.

Your animals will thank you for using animal-safe fertilizers.

So which fertilizer should you use? Lucky for you, I have a strong preference to share. For generic garden fertilizers, I highly recommend Mighty Grow. It's organic, processed poultry litter that slowly releases over a 90 day period. I've used it for a couple of years now, and it's my favorite. I particularly like it, because it's considered pet safe, and I have a dog that will gladly roll around in and lick the soil when it's extra-fragrant from fertilizing. In my raised beds, I add 13 lbs of Mighty Grow per 1000 square feet. My beds are about 72 square feet, so I need just under one pound of Mighty Grow per bed. (Three cups of Mighty Grow fertilizer equals one pound.) I top dress with the Mighty Grow, meaning that I just use a scoop to scatter the pellets right on top of the soil, then water it in thoroughly. I fertilize with Mighty Grow every three months. 

Alright, you've made it through the tedious part of garden soil management! Stay tuned; we've got cover crops, crop rotations, and composting ahead of us. Do you have a favorite fertilizer that you like to use? Any questions about soil tests? You can drop it in the comments below!

Happy growing, 

Mary Riddle