Q: I have cats that use my raised beds instead of their litter box. I planned on using chicken wire to help keep them out in the spring. Is my soil ruined because of their urine and excrement? Does the ammonia from the urine alter the pH?
A. No, it’s not ruined. Just rake out the feces and it will be fine. The urine is much less of a problem than the feces. If your garden is organic at all, it is similar to other animal manures.
The only problem would be for pregnant women. A summary of this problem can be found on the Centers for Disease Control website, www.cdc.gov/healthypets/pregnant.htm.
It is highly advisable that pregnant women not garden in this soil, handle freshly harvested vegetables or fruit coming from this spot without someone else thoroughly cleaning the produce before handling.
I would give the garden spot a thorough soaking before planting to flush excess salts. As with anything else, you should always wash your hands after gardening or handling fresh produce from soils containing any kind of compost. That goes for everyone.
The pH of our soil is very difficult to change for any length of time due to its high calcium carbonate (lime) levels. It just goes back up to wherever it was, usually around 8.2 or higher in unamended soil and about 7.6-7.8 for desert composted soils.
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 1,000 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.
Each year afterwards add 2 yards per 1,000 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.
Raised beds do not require hard construction sidewalls. Constructing hard sidewalls gives you about 6 inches of extra growing space around the edge of the beds. Constructed beds should be 12- to 18-inches tall and 3- to 4-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 at the UNCE Orchard in North Las Vegas or on my blog, xtremehorticulture.blogspot.com.
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 1 foot apart lengthwise down the beds. A 3- to 4-foot-wide bed would have three in each bed. The 4-foot wide would accommodate three as well but spaced further apart.