Shrub and Ornamental Fertilization Program

Why this matters

Most lawn-care companies focus exclusively on turf and treat the surrounding shrubs and ornamentals as "the customer's problem." The customer who hires a lawn-care service almost universally has shrubs and ornamentals on the same property and almost universally does NOT fertilize them. A simple shrub and ornamental fertilization program - 2 to 3 visits per year, deep-root-feed or surface granular - is one of the easiest add-on services to sell to existing customers and improves the appearance of the entire landscape, not just the turf. This article covers the procedure for a typical residential shrub and ornamental fertilization visit.

When to use this procedure

• Established shrubs, hedges, ornamental trees, foundation plantings
• New plantings after the establishment year (year 2+)
• Customers with visible nutrient deficiencies (yellowing leaves, slow growth, undersized blooms)
• Twice-per-year program: early spring (just before bud break) and late spring (after bloom)
• Optional: light fall fertilization for evergreens before dormancy

Do NOT fertilize during summer drought stress, during the establishment year of new plantings, or when soil temperatures are below 50 °F (roots are not actively uptaking).

Tools and materials

• Soil probe or auger for deep-root fertilization
• Hand-pump or backpack sprayer for liquid feed
• Granular spreader (small hand spreader for spot application)
• Granular fertilizer formulated for woody ornamentals (typical analysis: 10-8-6 or similar with slow-release N)
• Liquid root feed (typical: deep-root soluble feed with humic acid for soil biology)
• Acid-loving plant fertilizer (azaleas, rhododendrons, hollies, blueberries, evergreens - Holly-tone or equivalent)
• Iron supplement for chlorotic plants (chelated iron or iron sulfate)
• pH test kit + soil sample bag
• Hand rake for incorporating granular
• Watering can or hose for watering in
• PPE: nitrile gloves, eye protection, dust mask for granular application

Safety

Slow-release granular fertilizers are generally lower-risk but the dust during application can irritate airways. Wear a mask in dry, dusty conditions. Never apply granular during high wind; runoff into adjacent water bodies is a regulated discharge in many jurisdictions.

Selecting the right fertilizer

The pH of the soil is the variable. Acid-loving plants in alkaline soil show chlorosis (yellow leaves with green veins) and benefit from acid-formulated fertilizer plus periodic soil acidification.

Procedure - granular surface application

Step 1: Identify the plants

1. Walk the property, identify each plant type
2. Note any visible deficiencies (yellowing, leaf scorch, slow growth)
3. Photograph any plant the customer should see treatment notes on

Step 2: Calculate the application rate

Most granular fertilizers spec application rate per square foot of root zone (NOT per linear foot of plant). The root zone extends approximately to the drip line - the outer edge of the canopy.

Typical rate: 0.5-1 pound of granular per 100 square feet of root zone, depending on the bag specification.

For a single mature 6-foot diameter shrub: root zone ≈ 28 square feet, application ≈ 4-8 ounces of granular.

Step 3: Apply

1. Pull mulch back from the base of the plant
2. Distribute granular evenly across the root zone, starting 4-6 inches from the main stem and extending out to the drip line
3. Use a hand rake to lightly incorporate the granular into the top 1 inch of soil
4. Pull mulch back over
5. Water in with a hose to dissolve the fertilizer into the root zone

Step 4: Move to next plant group

Plants of the same type can be addressed as a group (e.g., a row of boxwoods gets a single calculation for total root area and one continuous application).

Procedure - deep-root liquid feed

For larger shrubs and ornamental trees, deep-root liquid feed delivers nutrients past the surface root zone into deeper roots:

Step 1: Mix the solution

1. Per the manufacturer's specification, typically 1-2 ounces of liquid concentrate per gallon of water
2. Higher rates (3+ ounces per gallon) are for deep-root injection by trained applicators with calibrated equipment

Step 2: Probe the soil

1. Insert the soil probe at 18-24 inches deep at the drip line
2. Inject the diluted solution slowly (about 1 gallon per probe hole)
3. Move 18-24 inches around the drip line and repeat
4. For a mature shrub, 4-8 probe holes around the drip line

Step 3: Repeat for each plant

Deep-root is more time-intensive than granular but reaches deeper roots and is the right method for ornamental trees.

Iron deficiency correction

Plants showing chlorosis (yellow leaves with green veins) - especially acid-loving plants in alkaline soil:

1. Test the soil pH (kit or send to extension lab)
2. If pH is above 7.0 and the plant is an acid-lover, treat with iron sulfate or chelated iron per the product label
3. Apply granular sulfur to lower pH over time (results take 3-6 months)
4. Re-test pH the following season
5. Mature trees with chronic chlorosis may need trunk injection (Mauget capsules or similar) - a specialty application beyond standard programs

Fertilization timing

References

• ANSI A300 (Tree Care Standards)
• ISA (International Society of Arboriculture) fertilization guidelines
• Cooperative Extension shrub fertilization bulletins (state-specific)
• EPA WaterSense + state phosphorus restrictions (some states restrict P application near water bodies)
• Manuall internal: Fertilization Program Design, Tree Shrub Pruning, Spring Mulch Refresh