How Much Compost to Add to Garden Depends on Soil

Q. I am starting a new garden spot. How much compost should I add to the soil?

A. If this is a new spot of raw desert soil or fill, the first year incorporate about 12 cubic yards of compost into 1000 square feet of growing area to a depth of 12 inches. The second year of growing incorporate half of that; the third year, half of what you applied the second year.

If desert soil has never had compost added to it or it was never in any kind of agricultural production then the first application will be very heavy. The second year not as much is needed and the third year the amount added is even less.

            Each year afterwards add 2 yards per 1000 square feet to maintain soil organic matter and production levels. Why so much? You can visit my blog and learn why.

            I would recommend growing in beds clearly identified for your garden. The areas between the beds are designated for foot traffic.

When compost is added at the rate of 12 cubic yards for every 1000 square feet it doesn't seem like much when it is incorporated to a depth of 12 inches.

            Raised beds do not require hard construction sidewalls. Constructing hard sidewalls gives you about six inches of extra growing space around the edge of the beds. Constructed beds should be 12 to 18 inches tall and three to four feet wide. Foot access should be provided on all sides of the bed.

            Raised beds will stay in place without hard sidewalls if constructed properly. You can see beds like these on the UNCE Orchard in North Las Vegas.

             

The second year about half of the compost is added to the raised beds that was added the first year to build soil organic matter. Raised beds do not need constructed hard sidewalls. Mulch is put down the center aisle for walking.

            Drip irrigation is best. Drip emitters should be about 12 inches apart for most crops. Crops that require closer spacing (onions, garlic, beets, and carrots) may require emitters closer than this. All emitters should release water at the same rate and pressure.

            Space tubing one foot apart lengthwise down the beds. A 3 - 4 foot wide bed would have three in each bed. The four foot wide would accommodate three as well but spaced further apart.

            Mulching vegetables during the summer heat helps. Use straw or a light topdressing (3/8 inch minus) of screened compost.

After amending the soil and building the raised beds, the drip irrigation is installed. This is drip tubing with emitters spaced every 12 inches along the tubing.

            If rabbits are a problem, fence the area with 2 ft. wide chicken wire, one inch hex, buried on the bottom edge one inch deep. Fertilize vegetables lightly once a month. Use a high phosphorus fertilizer at planting time. Irrigate daily during the summer months. Remove weeds daily when they are small.