Fall is Time for a Garden Soil Test

How's Your Soil? Get It Tested for a Better Garden.

October 17, 2019
Soil Test Earthworm

Happiness is a positive soil test, one that lets you know that you have been doing something right! Fall is the perfect time to take a sample of your soil. Just like humans, plants need nutrients to be healthy and productive.

We have worked for years to get the levels of pH, potassium, calcium, magnesium, and phosphorus in our garden soil up to the optimum levels. See more about NPK Ratios And What This Means.


This year we got the best test results ever! Everything is in the optimal to high range meaning we can ease off on applying amendments. I’m glad to have this report from the extension service to go by since too much of a good thing can do more harm than good.

The pH is high enough that I won’t feel guilty spreading ashes on the paths and driveway when it is icy instead of saving them for the garden. Since we burn wood we usually use them instead of lime to sweeten the soil.

The only recommendations were to spread 2 pounds of nitrogen per 1,000 square feet using either 33 pounds of soybean meal or 15 pounds of dried blood. I’ll stick to the soybean meal since the idea of dried blood makes me squeamish!

To maintain the perfect potassium level they recommend using 14 pounds of Sul-Po-Mag to supply 3 pounds of potassium per 1,000 square feet.

Absolutely no extra phosphorus is needed so any commercial fertilizer mix should have 0 for its middle number.


Manure and compost are excellent sources of nutrients but I might skip the free goat manure this spring and just use our home-made compost since the amount of organic matter in our soil also tested in the high range.

I’m very excited to be on track for another fruitful year in the garden come spring!


If you have been putting off getting your soil tested, now is the time as you put your garden to bed for the winter.


Soil testing services are offered by most state university extension services. It only takes a few minutes to take a representative sample and send it off. Maybe you will be as pleasantly surprised as I was. If not, you will have a game plan for the necessary action to take to bring your garden up to snuff. Good gardens start with good soil!

See my post on how to take a soil test.

About This Blog

Get inspired by Robin Sweetser’s backyard gardening tips and tricks. Robin has been a contributor to The Old Farmer’s Almanac and the All-Seasons Garden Guide for many years. She and her partner Tom have a small greenhouse business and also sell plants, cut flowers, and vegetables at their local Farmer’s Market.