Turf and Ground Cover Management

Chapter Introduction

This chapter covers the full range of competencies required for the Red Seal exam in Landscape Horticulturist regarding the establishment, maintenance, and management of turf and ground covers. You must master agronomic principles, application calculations, safety standards, and diagnostic techniques. Exam questions cover both theory and practice — every concept presented here may appear as a multiple-choice question or a scenario-based problem.

1. Botanical and Physiological Characteristics of Turfgrasses

1.1 Anatomy of a Grass Plant

The grass plant (family Poaceae) is distinguished by its growth in tillers. Each plant produces tillers from the crown, located at the collar, just below the soil surface. The essential parts to know:

Leaf: blade, sheath, ligule, auricle — identification criteria.

Stem: culm, with nodes and internodes.

Root system: fibrous, fasciculated, with a typical depth of 10 to 20 cm for cool-season species, up to 30 cm for warm-season species.

Stolons: horizontal stems above ground (e.g., creeping bentgrass).

Rhizomes: underground stems (e.g., Kentucky bluegrass).

Exam point: The growth zone (intercalary meristem) is located at the base of the leaf, which explains why mowing does not damage the growing point as long as the cutting height remains above the crown. Mowing too low (scalping) damages the crown and causes plant death.

1.2 Cool-Season Species (C3)

Species	Growth Type	Shade Tolerance	Drought Tolerance	Typical Use
Kentucky bluegrass (Poa pratensis)	Rhizomes	Low	Moderate	Ornamental lawns, sports fields
Creeping red fescue (Festuca rubra rubra)	Rhizomes + stolons	High	Moderate	Shade mixtures
Tall fescue (Festuca arundinacea)	Bunch-type (cespitose)	Moderate	High	Transition zones, low-maintenance areas
Creeping bentgrass (Agrostis stolonifera)	Stolons	Low	Low	Golf courses (greens)
Perennial ryegrass (Lolium perenne)	Bunch-type	Low	Low	Rapid establishment, overseeding

1.3 Warm-Season Species (C4)

Zoysia (Zoysia japonica): heat-tolerant, slow growth, winter browning.

Bermudagrass (Cynodon dactylon): very wear-tolerant, requires full sun.

Seashore paspalum (Paspalum vaginatum): tolerant of saline soils.

Important for the exam: In Canada, C4 species are used only in the warmest regions (southern Ontario, Okanagan Valley) and are often treated as annuals or installed as pre-cultivated sod.

1.4 Mixtures and Seed

A mixture contains several cultivars of the same species; an interspecific mixture contains multiple species. CFIA (Canadian Food Inspection Agency) standards govern seed purity and germination rates. The label must indicate:

Purity percentage (minimum 95% for quality seed).

Germination rate (minimum 80% for primary species).

Weed seed percentage (maximum 0.5%).

Date of analysis (valid for 9 months).

Exam calculation: Actual seeding rate = (recommended seeding rate) ÷ (purity × germination). Example: recommended rate 5 kg/100 m², purity 95%, germination 85% → 5 ÷ (0.95 × 0.85) = 5 ÷ 0.8075 = 6.19 kg/100 m².

2. Turf Establishment

2.1 Seedbed Preparation

Soil preparation is the most critical step. The mandatory steps:

33.Soil test: optimal pH between 6.0 and 7.0. Sample at 10–15 cm depth, in a zigzag pattern, minimum 10 cores per uniform area.

34.Drainage: If the soil is clayey, incorporate organic matter (compost) at a rate of 5 to 10 cm over the surface, then incorporate to 15–20 cm depth.

35.Leveling: Minimum slope of 1 to 2% (1 to 2 cm per metre) for surface water drainage. Never create depressions.

36.Tillage: Plough or rototill to 15 cm, then refine the surface layer (0–5 cm) to obtain clods smaller than 1 cm.

37.Base fertilization: Apply a starter fertilizer (high in phosphorus, e.g., 10-20-10) at the rate recommended by the soil test, generally 1 to 2 kg/100 m².

2.2 Seeding

Optimal period: Late August to mid-September (warm soil, autumn moisture, less competition from annual weeds). Spring seeding (mid-April to mid-June) is possible but riskier.

Methods:

Broadcast seeding: by hand or with a rotary spreader. Cross passes at 90° for uniform distribution.

Drill seeding: with a disc seeder, for large areas.

Hydroseeding: a mixture of seed, water, wood fibre mulch, and tackifier, applied under pressure. Used for slopes and hard-to-reach areas.

Seeding depth: 0.5 to 1 cm maximum. Seed buried too deeply will not germinate.

Rolling: After seeding, a light roller (100–150 kg) ensures seed-to-soil contact.

2.3 Sod Installation

Lay sod in a staggered pattern (like bricks), with tight joints.

Do not stretch the sod pieces.

Water immediately after installation, then daily for 2 weeks.

Installation can be done from May to October, but ideally in September to allow rooting before winter.

2.4 Initial Irrigation

First week: light, frequent watering (2 to 3 times per day, 5–10 minutes) to keep the surface moist.

Weeks 2 to 4: reduce frequency, increase duration (1 time per day, 15–20 minutes).

After the first mowing: deep, infrequent watering (2 times per week, 30–45 minutes) to promote deep rooting.

Exam rule: Field capacity is the amount of water retained by the soil after gravitational drainage. Water beyond field capacity is lost through percolation. Sandy soil has a low field capacity (~10%), clay soil a high one (~35%).

3. Maintenance of Established Turf

3.1 Mowing

Parameter	Ornamental Lawn	Sports Field	Low-Maintenance Lawn
Cutting height	5–7.5 cm	2.5–5 cm	7.5–10 cm
Frequency	1×/week	2–3×/week	1×/2 weeks
One-third rule	Never remove more than 1/3 of the height at once	Same	Same

One-third rule: If the lawn reaches 9 cm and the cutting height is 6 cm, the cut is acceptable (3 cm = 1/3). If it reaches 12 cm, you must mow at 8 cm, then again a few days later.

Direction alternation: Alternate mowing direction (north-south, east-west, diagonals) to prevent grain lodging and compaction.

Blades: Sharpened — a dull blade tears the leaf, creating a whitish surface and increasing disease risk.

Seeded turf: First mowing when the height reaches 8–10 cm, cut to 5–6 cm.

3.2 Fertilization

Typical program for cool-season climates (Ontario, Quebec, Maritimes):

Period	Fertilizer Type	Rate (kg N/100 m²)	Comment
April–May	Slow-release (30–50% N)	0.5	Spring green-up
June	Slow-release	0.5	Maintenance
August–September	Fast- or slow-release	0.5–0.7	Fall recovery
October–November	High K, low N	0.3–0.5	Winter hardening

Annual total: 2 to 3 kg of nitrogen per 100 m² for an ornamental lawn; 3 to 5 kg for an intensive sports field.

Application calculation: A 20 kg bag of 20-5-10 fertilizer contains 20% nitrogen = 4 kg of N. To apply 0.5 kg N/100 m², you need 0.5 ÷ 0.20 = 2.5 kg of fertilizer per 100 m².

Precautions:

Never apply fertilizer on frozen or snow-covered ground (risk of leaching and pollution).

Water after applying fast-release fertilizer to avoid burn.

Sweep hard surfaces (sidewalks, driveways) after spreading.

3.3 Irrigation of Established Turf

Water requirements: 2.5 to 3.8 cm of water per week during active growth. During drought, turf enters dormancy (browning) and can survive 4 to 6 weeks without water.

Irrigation duration calculation: If a sprinkler delivers 1.2 cm/h, to apply 2.5 cm, you need 2.5 ÷ 1.2 = 2.08 hours per week.

Container test: Place containers (cups) at different locations in the watered area; measure the volume after 30 minutes to verify distribution uniformity.

Watering times: Early morning (4 a.m. to 8 a.m.) to reduce evaporation and minimize leaf wetness duration (risk of fungal diseases).

3.4 Aeration and Decompaction

Core aeration: extraction of soil cores (5–8 cm deep). To be done in fall or spring, when the turf is actively growing.

Spiking: perforation without core removal — less effective, used for slightly compacted soils.

Frequency: 1 time per year for ornamental lawns, 2 to 3 times for sports fields.

Signs of compaction: thatch accumulation > 1.5 cm, persistent puddles, shallow root growth, broadleaf weeds (dandelion, plantain).

3.5 Dethatching (Scarification)

Thatch is a layer of dead plant tissue (stolons, rhizomes, sheaths) between the soil and the green vegetation. A layer of 0.5 to 1 cm is beneficial (insulation, cushioning). Beyond 1.5 cm, it retains water, promotes disease, and prevents root penetration.

Methods:

Scarification (vertical cutting): vertical blades that cut through the thatch. To be done in fall, in two crossed passes.

Aeration + topdressing: for golf courses, sand application to dilute the thatch.

3.6 Overseeding

When: when turf density decreases (< 50% cover), after stress, or to introduce more resistant cultivars.

Method: low mowing (3–4 cm), light scarification, seeding at 50% of the normal rate, rolling, watering.

Period: late August to mid-September.

4. Weed, Pest, and Disease Management

4.1 Turf Weeds

Type	Examples	Control Strategy
Annual broadleaf	Chickweed, lamb's quarters	Pre-emergent (dinitroanilines) or early post-emergent
Perennial broadleaf	Dandelion, plantain, white clover	Post-emergent (2,4-D, MCPP, dicamba) — fall application
Annual grasses	Crabgrass	Pre-emergent in spring (when soil temperature reaches 10–12 °C)
Perennial grasses	Quackgrass, annual bluegrass	Difficult to control — often requires spot treatment with glyphosate

Exam rule: Pre-emergent herbicides must be watered in (5–10 mm) within 24 hours of application to be active. Post-emergent herbicides must be applied in calm weather, with no rain expected within 24 hours, and at temperatures between 15 and 25 °C.

4.2 Major Pests

White grubs (beetle larvae): feed on roots. Detection: turf that lifts like a carpet. Intervention threshold: 10 larvae per 0.1 m². Control: insecticides (imidacloprid, chlorantraniliprole) applied in July–August, or entomopathogenic nematodes.

Sod webworms: larvae that sever leaves at the base. Detection: small mounds of silk and debris.

Cutworms: sever young plants at the crown.

4.3 Fungal Diseases

Disease	Favorable Conditions	Symptoms	Control
Brown patch (Rhizoctonia)	Heat + humidity	Brown rings of 15–60 cm	Reduce nitrogen, water in the morning
Red thread (Laetisaria)	Low nitrogen, cool humid weather	Red filaments on leaves	Nitrogen fertilization
Powdery mildew	Shade, humidity	White powder on leaves	Improve light, fungicides
Snow mold	Prolonged snow cover	Grey or pink patches at thaw	Avoid late nitrogen, mow short in fall

Key principle: Prevention (proper fertilization, adapted mowing, morning irrigation) is more effective than any fungicide.

5. Ground Cover Management

5.1 Definition and Roles

A ground cover is a low-growing plant (under 60 cm) that forms a dense mat, used to replace turf in areas where it is difficult to maintain: steep slopes, shaded areas, poor soils, under trees.

Roles: erosion control, weed suppression, aesthetics, reduced maintenance.

5.2 Common Species in Canada

Species	Hardiness Zone	Exposure	Planting Spacing	Characteristics
Vinca minor (periwinkle)	3–8	Shade to partial shade	30–45 cm	Evergreen foliage, blue flowers
Japanese pachysandra	4–8	Shade	25–30 cm	Evergreen foliage, very tolerant
English ivy (Hedera helix)	4–8	Shade to sun	30–45 cm	Vigorous, can become invasive
Creeping cotoneaster	4–7	Sun	60–90 cm	Semi-evergreen foliage, red berries
Creeping thyme	4–8	Sun	20–30 cm	Fragrant, foot-traffic tolerant
Hardy geranium	3–8	Sun to partial shade	30–40 cm	Long flowering, colourful foliage

5.3 Ground Cover Establishment

112.Soil preparation: complete weed removal (mechanical or chemical), organic matter amendment, leveling.

113.Planting: in a staggered pattern, at container depth. Water thoroughly after planting.

114.Mulching: 5–8 cm of organic mulch (shredded bark, wood chips) between plants to reduce weeds and conserve moisture.

115.Irrigation: 2 to 3 times per week the first year, then 1 time per week the second year.

116.Fertilization: slow-release fertilizer (14-14-14) in spring, at a rate of 0.5 kg/100 m².

Exam point: Planting spacing determines coverage time. For coverage in 2 years, plant at the recommended spacing. For coverage in 1 year, reduce spacing by 30%.

5.4 Ground Cover Maintenance

Pruning: once per year, in spring, to control growth and rejuvenate plants.

Manual weeding: necessary for the first 2 years, then the ground cover becomes self-sufficient.

Division: every 3 to 5 years for vigorous species (vinca, geranium).

Rejuvenation: for woody species (cotoneaster), severe pruning (cut back to 10–15 cm) every 5–7 years.

6. Standards and Safety

6.1 Equipment Safety

Mowers: check guards (hood, deflector), never remove safety devices. Wear closed-toe shoes, safety glasses, and hearing protection.

String trimmers: use the harness, keep hands and feet away from the cutting head.

Spreaders: calibrate before use, wear a mask when handling fertilizers and pesticides.

6.2 Pesticides — Federal Regulations

The Pest Control Products Act (PCPA) and the Pest Control Products Regulations (PCPR) of the Government of Canada govern the registration, sale, and use of pesticides. Key requirements:

Application permit: required for commercial pesticide application (except domestic-class products).

Label: legal document — any use not in accordance with the label is prohibited.

Re-entry interval: minimum period before allowing access to the treated area.

Application record: record the product, rate, date, area, and weather conditions.

Exam rule: The application rate is expressed in kg of commercial product per hectare (kg/ha) or in L/ha. Conversion: 1 kg/ha = 0.1 g/m².

6.3 Canadian Electrical Code — Chapter V

For the installation of electrical irrigation systems, the Canadian Electrical Code, Part I (CE Code) applies. Relevant points:

Rule 8-200: Conductors and equipment must be protected against overcurrent.

Rule 10-102: Grounding of control equipment.

Rule 12-100: Burial of conductors — minimum depth of 45 cm for control conductors (24 V) under a slab or sidewalk, 60 cm in other cases.

Rule 68-000: Specific requirements for swimming pools and spas (not directly applicable to irrigation, but must be known for adjacent areas).

Important: 24 V transformers for solenoid valves must be installed at least 3 m from pools and 1.5 m above the ground.

6.4 CSA B149.1 — Natural Gas and Propane

If the site has gas lines (e.g., for greenhouse heating or an ice-melting system), the CSA B149.1 (Natural Gas and Propane Installation Code) applies. Rule 4.2: piping must be identified and protected against mechanical damage. Rule 5.8: minimum distance between gas piping and electrical cables.

7. Practical Calculations for the Exam

7.1 Area Calculations

Rectangle: Length × Width.

Circle: π × r² (π ≈ 3.1416).

Triangle: (Base × Height) ÷ 2.

Trapezoid: ((Base1 + Base2) ÷ 2) × Height.

Example: A lawn of 25 m × 40 m with a circular bed of 3 m radius. Lawn area = (25 × 40) − (π × 3²) = 1000 − 28.27 = 971.73 m².

7.2 Spreader Calibration

Strip method:

155.Fill the spreader with a known quantity (e.g., 5 kg).

156.Open the orifice at the desired setting.

157.Travel a distance of 50 m at a constant speed.

158.Measure the spread width (e.g., 2 m).

159.Area covered = 50 m × 2 m = 100 m².

160.Weight remaining in the spreader = 3 kg → 2 kg applied over 100 m² = 2 kg/100 m².

7.3 Pesticide Rate Calculation

Formula: Product quantity (L or kg) = (Area in ha × Recommended rate in L/ha) ÷ 1.

Example: Treat 2,500 m² with a fungicide at 1.5 L/ha.

Area in ha = 2500 ÷ 10000 = 0.25 ha.

Quantity = 0.25 × 1.5 = 0.375 L (375 mL).

7.4 Irrigation Calculation

Sprinkler flow rate: Q (L/min) = Area watered (m²) × Precipitation (mm/h) ÷ 60.

Example: A sprinkler covers 50 m² and delivers 20 mm/h. Flow rate = 50 × 20 ÷ 60 = 16.7 L/min.

8. Common Pitfalls to Avoid

171.Confusing C3 and C4 species: Cool-season species (C3) have optimal growth between 15 and 24 °C; C4 species between 27 and 35 °C. An exam question may ask why a tall fescue lawn turns brown in midsummer — it is summer dormancy, not disease.

172.Forgetting the one-third rule: Mowing that removes more than 1/3 of the leaf height causes physiological shock. The exam often presents a scenario: "The lawn measures 12 cm, the cutting height is 5 cm" — the correct answer is to mow at 8 cm, then again later.

173.Calculating seeding rate without accounting for purity and germination: Always divide by the product of purity × germination.

174.Applying a pre-emergent herbicide too late: Crabgrass germinates when soil temperature reaches 10–12 °C. If application is made after germination, the product is ineffective.

175.Confusing aeration and dethatching: Aeration extracts soil cores; dethatching cuts thatch with vertical blades. Both are often necessary but at different times.

176.Neglecting soil pH: A pH outside the 6.0–7.0 range makes nutrients unavailable, even if fertilization is correct. Soil testing is the first step of any program.

177.Using a nitrogen-rich fertilizer in late fall: This promotes succulent growth that increases the risk of snow mold. Use a potassium-rich fertilizer (e.g., 0-0-30 or 5-10-30).

178.Forgetting electrical safety distances: 24 V transformers must be 3 m from pools. The CE Code requires specific burial depths.

179.Not calibrating the spreader: The exam may present a scenario where the spreader is set blindly — the correct answer is always to calibrate on a test area.

180.Confusing intervention thresholds: For white grubs, the threshold is 10 larvae per 0.1 m². Below this, chemical intervention is not justified economically or ecologically.

9. Summary

Establishment: Soil test, seedbed preparation, seeding at 0.5–1 cm depth, optimal period late August–mid-September. Seeding rate adjusted by purity × germination.

Mowing: One-third rule, height 5–7.5 cm for ornamental lawns, sharp blades, direction alternation.

Fertilization: 2–3 kg N/100 m²/year, divided into 3–4 applications, with priority on fall. Avoid late nitrogen.

Irrigation: 2.5–3.8 cm/week, morning watering, deep and infrequent.

Aeration: 1×/year (ornamental), 2–3×/year (sports). Dethatch if thatch > 1.5 cm.

Ground covers: Choose according to hardiness zone and exposure. Mulch 5–8 cm, planting spacing according to species.

Safety: PCPA/PCPR for pesticides, CE Code for electrical, CSA B149.1 for gas.

Calculations: Areas (πr², base × height ÷ 2), spreader calibration (strip method), pesticide rates (area in ha × rate/ha), irrigation flow (m² × mm/h ÷ 60).

Final exam advice: Read each question twice. Red Seal questions are designed to test understanding of principles, not memorization of isolated facts. If a question presents a scenario, first identify the underlying principle (one-third rule, field capacity, intervention threshold), then apply the corresponding calculation or procedure.

Turf and Ground Cover Management