Now, the average home won't generate THAT much compost. So chances are you'll need to buy some additional organic material (OM) to add to your garden bed, especially after a hot summer where most of the prior season's OM has disintegrated - quite literally.
Like POOF! I KNOW I put 2 inches of composted mulch in there, but it's all sand again!
It happens. Gardening and farming are an on-going process, not a once and done. So get used to that. Each season you're going to need to add OM. Do a little soil experiment. All you really need is a large jar, a little dish soap, a ruler and a sharpie.
And whether you decide, (and are able to), simply add to the top of the bed, or need to turn the soil over to bury newly emerging unwanted growth (i.e. weeds), you need to add OM to the soil before you plant. Check with your local municipality for low cost fresh compost. If push comes to shove and you need to buy it bagged, add as much of the home made compost as you can. Otherwise, get something alive in there. Be it worm castings (which I highly recommend), which we'll discuss later, or some freshly made compost tea. (More on that elsewhere). But just remember, something that's been bagged or bottled and sitting on a shelf for weeks, months or longer, is probably not still alive.
On top of OM, if you've planted and harvested from that plot, you've removed nutrients that need to be replenished.
That's why we grow food, to eat it, and get the nutrients from the soil into our bodies. So if you're eating the harvest, you're going to need to replace the nutrients - for them to be there again. That's just common sense. There's not an infinite supply of all things in the soil, especially if you're harvesting.
Yes, soil organisms help replenish, too. But we're gardening in N. Texas, not generally under ideal growing conditions, and we want results. This season. You need to feed your soil, or your plants won't feed you well. It's pretty simple.
So to best determine which nutrients you need, and which ones you may not, I recommend doing a simple soil test, at the very least. I pushed back on this for years, because I thought I didn't need a test so long as I added compost. My very seasoned farmer friend Beverly finally got it through my thick skull that in order to be a better farmer, a soil test was a no-brainer.
For one thing, sometimes your soil is missing key nutrients you just didn't think you needed. Other times you could be adding things you don't need to add. Too much of a good thing, isn't always good. It can throw things out of whack. Too much of one nutrient, can lock up the intake of another.
Additionally, you may be spending extra money on amendments you don't need. So why guess? Use that extra money on more seeds or plants, or on the amendments you do need so you have a better harvest. And sell or give away the bounty!
There are various sizes of soil test kits. Here is the one I used and was pleased with. You can get this kit to test 40x, 80x or even 200x. Whereas 200 might be overkill for the average home gardener, I do suggest a unique test for each different area of your garden, and here is why.
My main planting area is about 2 acres, including the high tunnel.
On paper, I have it separated into sections and I plant different crops in each section, each season. I wouldn't expect each section, each having grown different crops, to all need the same thing, each season.
So, if you have 6 raised beds and a spot over by the driveway and another in the front yard, and you plant various things in each, that's multiple tests - each season. You'll go through the 40x test faster than you think.
Now, if you only have a little area, a few pots, etc., then maybe you do only need a small kit, like this. Both have you adding reagents to the soil, which provides a more accurate test than just a simple soil probe.
With these tests, you are actually adding specific amounts of the various test solutions, or reagents, into tubes of some kind, mixed with soil. Then, you use the included color chart to compare the color the mixture comes out looking like to determine levels of N, P and K.
If you have ever measured the chemistry in a swimming pool, you can do this, too. It's science, but it's not rocket science. I promise. (OK, so if you are color blind, it might be a bit of a challenge. Get a friend to read the results for you.)
On a side note, for a first time soil test on newly turned ground that's never been fertilzed, you might consider packing up and sending some soil off to your favorite university (in Texas, most folks use TX A&M), or a private lab, like Texas Plant and Soil Labs, both of which can give you a much more detailed breakdown of both macro and micro nutrients. They'll provide a detailed list of suggested additions. Commercial growers generally do this - at least once a year.
I'll go into how to do a soil test a bit more in another post. For now, just know to avoid sampling areas such as small gullies, slight field depressions, terrace waterways, or unusual areas like where your dog does its business on a regular basis. (Hey my mom had the BIGGEST tomatoes on the block from the area the dog poop went into over the winter)
From TX A&M's directions here is how to collect a soil sample;
- Using a trowel or similar tool, scrape away any non-decomposed plant tissue and materials.
- Next, cut a core or divot 6 inches deep into the soil and place soil in a clean plastic container. (Do not use your bare hands to break up soil)
- Repeat this step 8 to 10 times in the lawn or garden which is being considered for testing.
- Air-dry soil if sample feels wet to the touch.
- When sampling fertilized areas, avoid sampling directly in fertilized band.
Then you follow the directions of the soil test kit. Easy peasy.
WHAT's NEXT?
Now, once armed with your soil test results, you should have a better idea of which soil amendments you're going to need to focus on.
If you need Nitrogen (N) you can add it from a lot of different sources including various types of manures, "meals", or blends of fertilizer already mixed, derived of those things.
A few choices could be
Feather meal
Blood meal
Cottonseed meal
Fish Meal
Chicken Manure (Composted) (we use in-house aged/composted chicken manure from our flocks)
Cow Manure (Composted)
Rabbit manure (Composted)
Goat or Sheep manure (Composted)
or my personal favorite - Horse Manure - again, fully composted - from a local stable
We need to age/compost the manures for various reasons, none the least of which is to kill all of the weed seeds that are consumed in the daily diet of these these animals. Putting down fresh manure can be "hot" in some cases, burning the roots of the plants. And, in some cases, it can be unsanitary and potentially dangerous due to the potential for pathogens in some manures.
The adding of fresh manures to soil should only be done well ahead of planting (90-120 days before harvest depending on the crop) so it can be broken down into the soil by the organisms.
If you need Phosphorus (P), there are fewer sources and usually they are bone or rock based.
Phosphorous soil amendments generally come in the form of a bone meal, or soft rock phosphate. NOT super, or triple super. Just regular rock phosphate. Again, these are products I'm suggesting. Most are the exact brands, but if you choose a different brand, just make sure the ingredient is the same and/or it's OMRI approved if you're striving to grow using clean products.
Potassium (K), is also a macro-nutrient because plants can take up
large quantities of K each season. Some freebie places you can find it
is wood ash and compost that is heavy on the banana peels. More likely
you'll add crushed products like sul-po-mag.
Let's say your soil is low on
everything. The tests came back pretty much devoid of nutrients.
Might it make more sense for you to just get a nicely
blended multi-purpose fertilizer? Sure. I've used and sold Maestro Gro's Texas Tee fertilizer for over a decade! (And I still special order this for pick up here at the farm. It's a little expensive to ship a 40lb bag)
But
I gotta tell you, it's going to be heavy on the N, because it's
primarily sold as a lawn fertilizer.
So for fall, lettuces, greens,
cabbage - go for it. I'll put in an order for fall pretty soon, so let
me know. It runs about $40 a bag or so.
But for things you're
trying to get to bloom, like broccoli, cauliflower, late crop of squash
or fall tomatoes, I do not suggest it, unless you're really low on N.
Too much N, and you're likely to get a lot of leafy foliage, and not a
lot of fruit. It's a good start, but if you're soil needs P and K, too,
there are better options.