General Planting Specifications for El Dorado County California
Plants shall be planted 3/4" higher than finished grade.Holes for plants shall be at least 3 times as wide as the plant container and a few inches deeper than the rootball. Backfill shall be free of an excess of rock or other non-soil debris. When planting in amended areas, the planting hole backfill shall be the existing amended soil. With all other plantings, the backfill shall be 2 parts loosened existing soil blended with 1 part amendment or compost. Native shrubs and trees shall have only unamended existing soil in their backfills .You may choose to use mycorrhizae when planting natives, its use may increase the
viability of the natives. All plants that prefer acidic based soil should have peat moss or 'acid based soil' as the amendment/compost for their backfill. (Plants that prefer acidic soil include rhododendrons, camellias, hydrangeas, Pieris, etc.)
All plants (except natives) installed shall have appropriate amounts of 6-20-20 fertilizer (or starter fertilizer) mixed into the top half of their backfill. For extended fertilization, place slow release teabag fertilizers in each hole per manufacturers rate. Do not use any fertilizer which includes nitrogen if planting June through August. Organic fertilizers are most often a better choice over synthetic fertilizers; they contribute to the health of the soil. Organic starter fertilizer is the recommended fertilizer at planting time.
All plants shall be watered as needed until installation. On day of installation plants shall be watered thoroughly prior to, and during or after planting.
All new trees shall be staked with two rigid stakes far enough away from tree and short enough so they don’t hamper growth or damage the tree's bark, but high enough to support the tree through the winter and winds. They will be tied with strong, flexible tie materials to allow a small amount of movement while still supporting the tree; figure eight patterns for tree ties work well. Stakes shall be as close to vertically level as possible, and shall be perpendicular to prevailing winds. Trees shall be released from stakes during non-windy seasons; stakes shall be removed as soon as tree is strong enough on it's own.
Before planting, all live weeds in area should be killed. This can be done manually, or in the presence of perennial weeds (such as bermuda grass) herbicides, such as glyphosate, can be used (use caution around other live plants you want to keep).
Mulch to a depth of 3"-4" can be applied to reduce weed problems; this won't be 100% effective, but it will prevent the majority of the weeds. The depth of the mulch will have to be maintained as the years go by (see mulch specs). The goal here is to block all light from reaching soil, reducing seed germination. DO NOT USE WEED CLOTH in planting areas, it prohibits the growth of healthy soil and healthy roots, and will eventually turn into its own source of litter.
All irrigation valves shall be separated to suit cultural needs of plants. This means med. and high water needs plants shall be on separate valves from low water needs plants. When possible, trees should be on their own valve; if this is not practical, they should be grouped on the same valve with low water needs plants (less frequency, longer run times). All lawn irrigation shall be on separate valves from all other plants; all drip valves should be separate from valves with standard forms of irrigation.
Drip Irrigation: IMPORTANT: All drip system valves must have a pressure regulator and a drip filter! All new plants irrigated with drip irrigation will typically use the following format: One gallon :At least 1 gallon total (can use one - one gallon or two- 1/2 gallon emitters) or emitterline
Five gallon:At least 5 gallons total (using a minimum of three emitters) or emitterline Fifteen gallon:At least 15 gallons total (using at least 7 emitters or 2 - half pattern shrubblers or emitterline) Emitters should be distributed around rootball so the maximum area of surface above roots receives water. All emitters shall be diaphragm type / pressure compensating, or 1/4" emitterline. When microspray / shrubblers are installed on a drip line with pressure compensating emitters, the emitters may lose their pressure compensating qualities; this can have a negative effect on irrigation systems in landscapes with slopes.In the case of more than one emitter per plant, all emitters shall be distributed evenly over the rootball, preferably
on the uphill side. All emitters on 1/4"-1/8" lines leading to plants to or from emitters shall be staked to the ground; no loose tubing! All polyethylene tubing shall be staked to ground at least every four feet. All polyethylene tubing shall be covered by mulch; in cases where this is not practical, cover it by no more than 1.5" of soil.
Using mulch is always recommended, a shredded bark product works well . Mulch should be applied at least 3"-4"thick for effective weed suppression. Any mulch should be 3"-6" away from the stem/trunk of any plant - in the case of very small plants (6-pack or smaller) this distance can decrease to 1"-2". Mulch shall be installed over drip systems, with any microspray or shrubblers extending over the top of the mulch. Mulch is usually reapplied every 2-4 years. Its presence helps suppress weed growth, it helps conserve water by limiting evaporation, modu-
lates the temperature of the soil, and when applied directly over soil can eventually improve the structure of a soil.