Roadside Revegetation

IMPLEMENTATION GUIDES
planters standing around, and be surprised to find that the seedlings are not at all what you
were expecting.
10.3 INSTALLING PLANT MATERIALS
Once the project site has been prepared (see Section 10.1, Soil and Site Treatments) and
the plant materials have been obtained (see Section 10.2, Obtaining Plant Materials), the
vegetation can be installed on the project site. The following implementation guides cover
the methods for installing seeds, cuttings, and plants. Section 10.3.1, Seeding, discusses the
different methods of seeding, how to formulate seed mixes, determining seeding rates, and
assuring quality. A specialized form of seeding, hydroseeding, is discussed in Section 10.3.2,
Hydroseeding. Section 10.3.3, Installing Cuttings, outlines cutting installation techniques
most commonly used in biotechnical engineering designs. Section 10.3.4, Installing Plants,
discusses techniques for planting bareroot and container plants. It also discusses seedlings,
plant handling, storage, and quality control measures.
10.3.1 SEEDING
Introduction
Seeding is the distribution of seeds for the purpose of establishing seedlings at a desired
density and species composition. Optimal seeding operations must take into consideration
(1) how seeds are uniformly distributed over an area, (2) where seeds are placed vertically
(that is, in, on, or under the soil surface), (3) species composition in the seed mix, and (4) when
seeding takes place. These factors must be adapted to each revegetation unit to account for
the unique climate, soils, and species requirements of each site.
Seeding is often coupled with other operations, such as fertilization, soil amendment applications,
and soil stabilization treatments. While accomplishing these objectives at the same
time as seeding often makes practical sense from an economic and scheduling standpoint, it
might not always be best for the short-term establishment of native vegetation. It is important
to consider the effects of combining too many operations into the actual sowing operation. It
may be necessary to plan some of these operations at different times. For example, fertilizing,
which is often done during the seeding operation, might best meet objectives if applied
separately from seeding (see Section 10.1.1, Fertilizers).
This section will cover the different steps in developing a seeding plan: (1) identifying seeding
areas, (2) determining seed application methods, (3) developing seed mixes, (4) determining
sowing rates, (5) preparing seed mixes, (6) selecting sowing dates, and (7) applying seed and
assuring quality.
Identify Seeding Areas
It is important to visit the project site as soon after road construction as possible and specifically
identify seeding areas on the ground. If road construction is a multi-year project, finished slopes
should be assessed for seeding while the remaining construction continues. While most of the
seeding areas will conform to the revegetation units developed during planning, sites always
look different after construction. A field review should note where topsoil has been placed,
presence of surface rock, surface roughness, accessibility by equipment, microclimate, soil
compaction and other site factors. These factors will be used to develop (1) seeding methods,
(2) sowing dates, (3) seed mixes, and (4) seeding rates for each of the seeding areas.
Seeding areas are located on a map and by road station. For each seeding area, acreage can
be calculated using methods described in Figure 9.2 in Chapter 9. These calculations must
consider the areas where seeding will actually take place. For instance, seeds should not be
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