[HISTORY: Adopted by the Board of Commissioners of the Township of Lower Merion 5-17-1989 as Sec. 5 of Ord. No. 3155. Amendments noted where applicable.]
The following plantings are recommended:
Planting materials for wet or dry conditions (recommended for use in and around stormwater management basins and related facilities).
Footnote: For plant sources and availability, applicants are encouraged to consult the following publications:
Specifications for trees.
All trees planted within the road rights-of-way shall be approved species and varieties and shall conform to the full requirements of the Shade Tree Commission in size and form.
All trees shall be true to name, nursery grown, unless otherwise approved by the Township Arborist, and free of all injurious insect pests, plant diseases or unhealed trunk or basal scars.
All trees or, at a minimum, representative samples of all trees shall be subject to inspection at the planting site prior to planting (it is recommended that representative samples of all trees be inspected, rather than all trees, in the event that any or all trees are rejected). Plantings will be approved or rejected for cause. All plantings shall conform to the standards of the publication American Standard for Nursery Stock, ANSI Z60.1 - 1980 of the American Association of Nurserymen, as amended.
All plants must be dug with ball and burlap and shall conform with the ball diameter to depth ratio standards of the publication American Standard for Nursery Stock, ANSI Z60.1 - 1980, of the American Association of Nurserymen, as amended, i.e., one foot of ball for each inch of trunk caliper measured one foot above ground and shall be not less in depth than 2/3 of the ball diameter. Wire baskets which may be used to transport trees shall be removed prior to planting.
Trees should be planted in elliptical planting holes rather than the traditional straight-sided holes (see Figure 1). Holes should be dug at least two feet wider than the greatest width of the tree ball for trees of less than five inches' caliper and four feet wider for trees of greater than five inches' caliper. All trees shall be planted at the same depth as the ball. The tree shall be set on firm soil that has not been loosened or to which soil amendments have been added (this is to prevent future settling of the tree to below the point that the tree was originally grown naturally or in the nursery row). Check each tree for the start of the flair or the root system and plant at that depth. Untie the burlap on the ball and pull it down to the bottom of the ball. Plastic burlap, if used, shall be removed. Use good quality topsoil in planting. Firm up soil to ensure soil contact to root mass. Water the tree until the entire root ball is wet. Thereafter, keep the root system moist but not wet. Injured, diseased trees and trees with broken branches or double leaders should be pruned. With trees with double leaders, remove either one of the double leaders totally. Do not top the central leader. Stake the tree using flat strapping or webbing instead of wire, making sure the tree can move at least one inch in either direction. Double bracketing is best with a support on each side of the tree. Examine ties during growing season since trees can be girdled if they grow too quickly. Mulch saucer of tree but do not pile mulch on tree trunk. Leave three inches of bare soil adjacent to trunk. Maintaining a permanently mulched area around the tree promotes growth and helps prevent mowing injuries.
Editor's Note: Figure 1 is available for inspection in the township offices.
Take customary precautions according to the standards of the American Association of Nurserymen in preparing plants for digging, moving, transplanting and planting.
Specifications for shrubs. Plant material should be balled and burlapped or container grown.
Spacing. Unless a hedge is desired, give shrubs room to grow by providing proper spacing; place planting holes on centers that approximate the height of the shrub at maturity. If set against a building, shrubs should not touch walls or be planted in the building's dripline, where plants can be damaged by excessive runoff and falling ice and snow. Do not plant in areas that will have large piles of snow from plowing of parking lots or roadways.
Dig a separate hole for each shrub. Add organic materials such as peat moss, leaf mold or compost to soil. Holes should be dug at least eight inches wider than the shrub and the same depth as the ball (see Figure 2). Plants must be taken out of containers and plastic burlap must be removed. Natural fiber burlap may be left, but loosen the top and remove from shrub's stem.
Editor's Note: Figure 2 is available for inspection in the Township offices.
Set the shrub at the same level as grown at the nursery; fill with mixture of soil and organic material until the hold is 2/3 full; water. Build saucer around shrub and finish filling, tamping to ensure good soil to root contact. Water and cover with mulch; do not pile mulch deeper than three or four inches. Prune out any broken branches. Maintain a watering schedule whenever rainfall is insufficient to keep the soil moist. A slow release fertilizer should be added early in the spring of the second year.
Azaleas and rhododendrons and other ericaceous plants must be planted in soil with a pH value of between 4.5 and 6.5. These plants are fibrous rooted and grow within the upper 12 inches of soil. A mulch will keep the topsoil cool and aid in their growth.
Mulch on all shrubs should be renewed yearly to keep down weeds, conserve water and increase soil humus.
Specifications for planting under wet and dry conditions (recommended for use in and around stormwater management basins and related facilities). In areas prone to flooding, a plan can be designed to create an ecosystem capable of withstanding occasional flooding, be aesthetically pleasing, biologically diverse and need limited maintenance. As each site is unique, each site needs an original plan based on site conditions.
Wet meadows or basin floors.
Clump-forming grass species should be selected rather than mat-forming grasses to allow space for wildflowers. Species used should be native or naturalized species, where possible, with a mix of annual, biennial and perennial and with a succession of blooming time.
Soil tests of basin floors in stormwater facilities, including tests for organic content, should be undertaken and fertilizer added only if necessary. Where fertilizer is used, a slow-release variety should be used as seedlings are unable to absorb large amounts of nutrients and the possibility of nutrient-rich runoff may occur.
In stormwater management facility construction, simply saving the topsoil of a biologically rich site, rather than burying it during construction, would preserve many of the rhizomes and seeds of native grasses and wildflowers.
Seeds pressed into the soil by drills or roller seeders have better access to soil moisture. Drop or cyclone spreaders are effective, as is hand sowing. Lightly rake over the area or use tine harrow to ensure proper soil-seed contact.
Seed can also be hydroseeded onto slopes, hard to reach or wet areas. For best results, do not mix the mulch in with the seed; spray the mulch over the seed in a separate application.
Meadow species are mostly perennials and require several years for good establishment.
Because most soil contains dormant seeds, it is not unusual to see weeds the first year. These can be mowed if they are in such quantities to cause a problem. Using a rotary mower is recommended as they mulch as they cut.
The practice of allowing native species to mature before they are moved allows many to reproduce and survive. After the second year, one annual mowing either in late fall or early spring before April 1 will maintain the meadow. Woody invaders must be eliminated from the site, either by mowing or removal.