After you have cleared the slope of the old plant material, the next step is to upgrade the irrigation system. Drip irrigation is a good method for irrigating a slope that will have a relatively few amount of plants (1 per 20 sq ft). The drawback to drip irrigation is that in some rural areas, the local critters (gophers, squirrels, raccoons) love to chew up the lines in search of water. So I actually prefer using rotors for irrigating a slope. MP Rotators by Hunter are an outstanding product for controlling water on a slope. This product can be found at both Ewing Irrigation and Hydroscapes here in San Diego.
Following the irrigation tune-up (or overhaul if needed), you next need to amend the soil. Gro-Power and composted top soil are usually the best materials to use for fixing up the soil (although every slope is different). See the earlier article in March about fixing soils.
After you have put down your soil amendment, you need to lay jute netting up and down the slope (see photo). Jute netting is a bio-degradable material (sometime referred to as erosion cloth) that serves 3 purposes and is critical to the success of slope planting. Jute netting not only holds the soil amendments in place but after planting it holds the mulch in place around the new plants. Finally jute netting helps to keep water from just running wildly down the slope. One large roll usually measures 4’ x 225’ (900 sq ft). Always lay the netting up and down the slope, never side to side and use the pins to secure it in place.
Once the netting is in place, it’s time to plant the plants. On each plant it is important to build a little berm on the downhill side of the plant. This helps to hold the water in place around the new plant’s root ball. Also when you place the plant in the ground don’t forget the Best-Pak (the slow release fertilizer I have mentioned in earlier articles). Place the Best-Pak on the uphill side of the root ball then soak each plant with a hose.
Next add some mulch and a pre-emergent herbicide like Preen to the slope to control the weeds. Spread at least 2 inches of mulch over the entire slope (the depth of your thumb). 1 cubic yard of mulch will cover 150 sq ft feet to the depth of your thumb.
Finally, carefully water the new plants again in order to wash the mulch and Preen off of the foliage. Continue to soak each new plant over the next few weeks to help them get established. The exact watering schedule depends on the plants and the time of year you have planted your slope.
