Transfered from my Google Knols to be stored on this blog.
Raised beds are outstanding for many reasons. In this case, you can concentrate all of your resources to a bed. The peat moss and composted materials will go exactly where you want them to go and they will only be used by the planted vegetables. This fact, is one way raised bed gardening saves you money.
Amending Your Raised Bed Vegetable Garden Soil (Yearly!)
By Gary Pilarchik LCSW-C
Amending Your Garden Plot with Peat Moss and Humus (Moisten!)
Every year I add to my garden's soil. I use raised beds and can concentrate resources right to the beds. Last year I re-dug the beds to 2 feet deep. You don't have to do that yearly. Because I am using a raised bed and don't walk in it, the soil stays loose. However, I do have clay soil. Great for micro nutrients but it is heavy. I want to improve the soil of my beds and I work on that yearly.
Every year I amend it with peat moss and composted materials and grass clippings. This freshens up my planting beds and it reworks the top 12 to 24 inches of earth, depending on what I am planting. This is how I do it. There is no exact science or measurements to this. Don't stress out over pefection.
Below are pictures of the beds and supplies. These are 4 x 6 raised beds. They have to be cleaned out. I have a bag of 3 cubic feet of dried compressed peat moss. The cost is about $10 a bag. The other 2 bags are composted humus and manure. The cost is about $2.75 a bag. The blue container is used to mix the peat moss with water. I can't stress this enough... moisten your peat moss before you use it.
Step One: Clean out the beds
What can I say... clean them out. I would bag all debris and put it curb side. This reduces the risk of over wintering disease and bugs, coming to life. Skip composting for the first spring clean out. Unless you know your material will be thoroughly decomposed by the time you use it.
Step Two: Prepare the peat moss (moisten!)
Peat moss is baked dry I believe. It is dry dry dry. Dusty and dry. You want to add water to it so it goes into the garden moist. If you put dry peat moss in your garden, you get a dust storm and it actually initially struggles to absorb water. When you plant seeds in dry peat moss and then water it, the peat moss actually floats up on the water and it can mess up your seeds. So moisten it. You could substitute peat moss with other materials if you wish. It should be in a form of very fine particles like peat moss.
This is a large container that is probably 25 gallons. Peat moss is hard to moisten because it floats. Fill your container halfway so you can reach your arms into it and turn it easily. Put in a good amount of water and then mix by hand. The trick is to sort of pet the peat moss in big circles. This rolls the water and peat moss together. Just mixing it under doesn't work. You have to rub the particles into the water. It is THAT DRY! The peat moss should be moist not soggy. When you squeeze it, water should not run out of it.
Step Three: Dump in the moistened peat moss
The darker pile is the moistened peat moss. It expands when wet. That is how you want your peat moss to be when amended into your soil. Notice the lighter brown pile, that is the dry peat moss. In a 4 x 6 plot you want to put in about 1/2 a bag of peat moss in to start. I have clay soil. If your soil is in better shape... use less. Worse shape... use more.
Step Four: Spread the moisten peat moss out
If you don't have enough to cover the plot by about a 1/2 inch, you can add more. There is no science to this. Keep in mind peat moss is acidic. It is a good idea to sprinkle a few handfuls of pulverized lime on top of the spread before you mix it under. I put lime down and the end of the season. Lime is alkaline. Peat moss is acidic. You typically want you garden soil neutral but that is another blog and Knol entry.
Step Five: Turn it under to at least 12 inches deep
Grab a shovel and turn it under to 12 inches or more. This is for the roots and worms.
Step Six: Add some more moisten peat moss to the turned bed
I used nearly the rest of my peat moss bag. I saved some (like 4 shovels full) for the composted humus and manure. You will have to remember to moisten the peat moss. Cover the space of your bed and work it in to the top 4-6 inches. You can see where the shovel is, that it has been worked in to the garden. I do it with my hands. I like the process of breaking the clay and mixing the soil by hand. It also lets me find rocks to remove.
Step Seven: Smooth and admire the finished bed
This bed is ready for planting. The composted humus and manure will be used at planting time. Notice the difference between the amended front bed and the untouched bed in the back. Remember... moisten your peat moss.
The composted humus and manure could be mixed in with the peat moss if you want too. There is no science to this. I use the composted manure when I plant the seeds and plants. This is your choice. If you want use the composted materials during this stage... add a bag to Step 4 and add a bag to Step 6. I prefer to use mine at the time of planting and will demonstrate that method in another Knol.
*Fertilizing can also be done at both Steps 4 and 6. You can add what every type of fertiziler you want as per the directions.