Basic Vegetation

Question 1

What are four advantages of leaving undisturbed areas?

Answer 1

1. ) minimizing clearing costs
2. ) native vegetation is likely both mature and adapted to the local environment
3. )leaving vegetation can filter runoff
4. ) soils that are undisturbed have a higher infiltration rate

(Module 6/ Pages 12-13)

Question 2

What would the term “growing medium” refer to?

Answer 2

Soil

Question 3

Soils with high bulk density with have low infiltration. What might be a second problem with a soil with high bulk density?

Answer 3

The soil may be impenetrable to plant roots and plants will have a difficult time becoming established.

(Module 6/ Page 16)

Question 4

If the bulk density of soil in forested land would be 1.03 g/cc and the bulk density on concrete is 2.2 g/cc, what would be the average bulk density of a residential neighborhood?

Answer 4

Typically 1.69 to 1.97 g/cc

Module 6/ Page 16

Question 5

The majority of soils in Virginia have what pH reading?

Answer 5

They are acidic the average pH reading is between 5 and 6.5

Module 6 / Page 17

Question 6

What is a good pH range for topsoils used on construction sites?

Answer 6

Between 6 and 7.5

Module 6 / Page 17

Question 7

If a soil has a low pH, what is the best method to raise the pH?

Answer 7

By applying lime

Module 6 / Page 18

Question 8

In general, fertilizers are used to supply plants with what?

Answer 8

Nutrients

Module 6 /Page 18

Question 9

What nutrients are in short supply in soil and can be added with fertilizer?

Answer 9

Nitrogen (N)
Phosphorus (P)
And Potassium (K)

(Module 6 / Page 18)

Question 10

When a fertilizer has three numbers what do the refer to and in what order? An example might look like this: “10-20-10”

Answer 10

The three numbers refer to the amount of nitrogen, phosphorous, and potassium.

(Module 6 / Page 18)

Question 11

If a fertilizer bag says it is 10-5-7 and the bag is 75 lbs, how much potassium is in the bag?

A) 5 lbs
B) 5.25 lbs
C) 7 lbs 
D) 3.75 lbs
E) 10 lbs

Answer 11

5.25 lbs

.07 * 75 lbs = 5.25 lbs

(Module 6 /Page 18)

Question 12

If a site can not be seeded within a required timeframe due to frost or drought, what action should be taken?

Answer 12

The site still must be stabilized. A good option would be using mulch.

(Module 6 / Page 19)

Question 13

What is the difference between annuals and perennials?

Answer 13

Annuals live for one year or season and should be used for temporary seeding.

Perennials, under normal circumstances, live more than one year.

(Module 6 / Page 20)

Question 14

Why is topsoil much darker than subsoil?

Answer 14

Topsoil is darker due to the accumulation of organic matter since it is the soil layer with the most biological activity, water, and nutrients required for plant establishment

(Module 6 / Page 21)

Question 15

In some instances, can subsoil be a good substitute to topsoil?

If so, when?

Answer 15

Yes. Subsoil can be a good substitute if properly limed and fertilized. And used in low maintenance areas.

(Module 6/ Page 21)

Question 16

How much topsoil is needed?

Answer 16

2 to 4 inches

Module 6/ Page 21

Question 17

What should you do to subsoil before placing topsoil?

Answer 17

Scarify the subsoil to a depth of 2 inches before spreading topsoil.

(Module 6/ Page 22)

Question 18

When placing mulch, how much is recommended?

Answer 18

2 tons per acre

Module 6/ Page 22

Question 19

What is a tackifier?

Answer 19

A cellulose-like material that contains a binder used when seeding and mulching with the use of a hydro-seeder.

(Module 6/ Page 22)

Question 20

What type of slopes may be warmer and drier and therefore make it difficult to establish new vegetation?

Answer 20

Slopes oriented facing the south or southwest

Module 6/ Page 23

Question 21

Annuals generally only last one year. What are other characteristics that make them ideal for temporary seeding?

Answer 21

• Germinate quickly
• Survive under more adverse conditions
• inexpensive to purchase

(Module 6/ Page 23-24)

Question 22

Which of the following options for temporary seeding are “potentially non-native invaders” and should be planted with caution?

• Oats
• Rye
• Weeping Lovegrass
• Annual Ryegrass
• German Millet
• Korean Lespedeza

Answer 22

Weeping Lovegrass and Korean Lespedeza are listed by the USDA as potential non-native invaders

(Module 6/ Page 23)

Question 23

What is a problem in using a contractor’s mix while permanent seeding?

Answer 23

Contractor’s mixes are not site specific and done without the recommendations of a landscape architect or planner

(Module 6/ Page 25)

Question 24

What is the most cost effective measure in controlling erosion?

Answer 24

Preserving existing vegetation

Module 6/ Page 12

Question 25

In what areas would sodding be recommended?

Answer 25

High maintenance areas or areas requiring instance cover like ditches or swales. (Module 6/ Page 26)

Question 26

How long can sod be placed after it is harvested?

Answer 26

Sod needs to be placed within 36 hours | Module 6/ Page 26

Question 27

Sodding can be established almost all year long, but what circumstances would prohibit placing sod?

Answer 27

If soils are soggy, excessively dry, hot, or frozen | Module 6/ Page 26

Question 28

What is a native species?

Answer 28

Those that naturally occur in the region in which they evolved. (Module 6/ Page 36)

Question 29

What plant, currently mentioned for use in the Virginia Erosion and Sediment Control Handbook, does DEQ highly discourage the use of (especially in Stormwater channels and stream banks) since it is highly invasive?

Answer 29

Chinese Lespedeza | Module 6/ Page 37

Question 30

What two reasons make using a seed mix highly desirable?

Answer 30

-because some native plants take longer than one year to fully establish and by placing a mix you prevent establishing a monoculture (Module 6/ Page 38)

Question 31

How many different planting seasons are there?

Answer 31

3 summer, spring, and fall/winter | Module 6 / Page 25

Question 32

What species are good for planting in the summer for temporary seeding?

Answer 32

German Millet, Weeping Lovegrass, and Korean Lespedeza | Module 6 / Page 25

Question 33

What species are good for planting in the fall/winter for temporary seeding?

Answer 33

Rye and annual ryegrass | Module 6 / Page 25

Question 34

What species are good for planting in the spring for temporary seeding?

Answer 34

Oats, Korean Lespedeza, and annual ryegrass | Module 6 / page 25

Question 35

How many different native species can you name that are alternatives to using invasive or over-used species in low maintenance areas?

Answer 35

Roundheaded bushclover, Partridge pea, Butterfly weed, Joe-pey weed, Orange coneflower, Big blue stem, Indian grass, side oats grama, Switch grass, Broom sedge, Deertounge, Canadia wildrye, Bottlebrush grass, and Virginia wildrye (Module 6 / Page 26)

Question 36

How many different invasive or over-used species can you name?

Answer 36

Chinese lespedeza, Birdsfoot trefoil, orchard grass, Redtop, weeping lovegrass, crownvetch, tall fescue, Kentucky bluegrass (Module 6 / Page 26)

Question 37

What is sprigging?

Answer 37

The planting of sprigs, or plant sections that includes crowns and roots at spaced intervals in furrows or holes either done by hand or with mechanical row planters. It uses no soil with the plants and is an alternative to seeding, plugging, or sodding. (Module 6 / 21)