Show #157 - Fall Lawn & Garden Q&A: Get Your Lawn and Plants Ready for Success

September is the perfect time to put fall lawn care into action, and Show #157 of Great Gardens Radio tackles some of the most common questions homeowners have about lawn renovation, grass seed, fertilizer, weeds, grubs, plants, and soil.

The episode’s central message is consistent throughout: the environment matters more than simply adding more products or more seed.

Whether you’re repairing a few bare spots or renovating an entire lawn, the right soil, water, fertilizer, seed selection, and timing can make all the difference.

Can You Mix Grass Seed, Fertilizer and Lime?

Yes.

The episode explains that a hydroseeder essentially combines these components, although homeowners can also apply them individually.

After core aerating, the show compares the lawn to a patient on an operating-room table: once you’ve opened the soil, move quickly through the renovation process.

The recommended sequence is to:

• Core aerate
• Topdress with soil
• Apply fertilizer
• Apply lime
• Apply grass seed

After seeding, the episode recommends watering from 5–8 p.m. rather than in the morning.

How Soon Can You Seed After Spraying Weed Killer?

The episode emphasizes that traditional spraying may leave inconsistent coverage.

According to the show, adding 1 ounce of Wilt-Pruf as a non-ionic spreader-sticker helps laminate the product over the target surface.

The episode says this allows homeowners to seed immediately because the weed-control product is contained within the Wilt-Pruf application.

The dying weeds can also serve as a temporary, self-removing cover for newly seeded areas as the seed begins to germinate.

What About Difficult Weeds?

The same principle is applied to dense weed growth such as:

• Japanese stilt grass in shade
• Bermuda grass in sun

The episode explains that once these dense plants are sprayed, the dying vegetation can provide a temporary cover over the seed.

Can You Apply 24-Hour Grub Killer Over New Grass Seed?

According to the episode, yes.

Dylox 24 Hour Grub Killer is described as safe to apply over newly seeded grass, and watering the product in can also help provide moisture to the seed.

The episode recommends treating sunny lawns and sunny mulch beds where grub populations may be higher.

Grubs Aren’t Just a Lawn Problem

Japanese beetle grubs are only one of the seven grub types discussed in the episode.

Plants that attract adult beetles can also be areas where grubs develop.

The episode specifically calls attention to:

• Roses
• Japanese Maples
• Japanese Flowering Cherries
• Sunny lawns

The recommendation is to apply Dylox around the soil of these susceptible plants because grubs can overwinter there.

Should You Trim Plants in Fall?

The episode’s answer is no—particularly after August 1 for plants setting their spring flower buds.

At this point in the year, many spring-flowering plants are establishing the buds that will become next year’s flowers.

Trimming now can remove those developing flower buds and reduce spring bloom.

The episode’s broader message is to understand whether a plant is growing foliage or setting flower buds before reaching for the pruners.

Why Does Hydrangea and Viburnum Foliage Look Damaged?

Late-season foliage damage isn’t necessarily a fungal disease.

The episode explains that some spotted or damaged foliage on plants such as Hydrangea and Viburnum is normal at this time of year, with fresh foliage developing the following spring.

It also points out that significant foliage damage can often be related to insufficient fertilizer, water, and mulch, rather than automatically being a fungus problem.

Are Small Brown Lawn Spots Caused by Grubs?

Not necessarily.

The episode explains that grubs return to the lawn in early August and begin as very small, first-stage larvae.

However, the brown dormant areas discussed in the episode are associated with the extreme heat and drought conditions that occurred in late June.

The show notes that this damage occurred during approximately 100-degree weather with no rainfall.

When Is the Best Time to Treat Grubs?

The episode identifies this period as the ideal time to treat for grubs and specifically recommends 24 Hour Grub Killer by BioAdvanced, rather than a grub preventer.

The larger lesson is that plant and lawn health problems can appear long after the original stress occurred.

A lawn isn’t one plant—it is thousands of individual grass plants, each requiring adequate water and nutrition.

Why Did Two of My Six Azaleas Die?

If several plants are treated similarly but only one or two fail, that doesn’t necessarily mean those plants were defective.

The episode says short-term plant death is most often associated with lack of water, while poor blooming performance over the medium term is commonly associated with lack of fertilizer.

Other variables can include:

• Sun exposure
• Poor mulching
• Root balls that aren’t completely covered
• High-salt fertilizer
• Box-store fertilizer
• Irrigation system design

The episode emphasizes that individual plants can be surviving on the edge of their available resources even when neighboring plants appear healthy.

Modern Irrigation Systems Can Miss the Root Zone

One of the episode’s more important observations concerns irrigation.

Many modern watering systems are designed primarily around lawns, where much of the lawn’s chemistry occurs in the top inch of soil.

Trees and larger plants, however, have root balls that can extend much deeper into the soil before they are established.

That means simply having an automatic irrigation system doesn’t necessarily mean your plants are receiving the water they need.

Are 10-10-10 and Specialty Fertilizers Outdated?

The episode calls simple fertilizer formulas such as 6-10-10, 10-10-10, and 10-6-4 products from another era.

The show argues that gardeners don’t need a different fertilizer marketed specifically for every type of plant.

Instead, it recommends focusing on a quality fertilizer containing slow-release nitrogen and trace elements.

Examples discussed include:

• PlantTone 21-5-12 + minors
• Fertilome Start and Grow 19-6-12 + minors
• Anderson’s 18-6-12 + minors

The common feature is substantial slow-release nitrogen designed to feed plants gradually over many weeks.

The First Number Is the “Money Number”

The episode places particular emphasis on the first number in a fertilizer analysis because it represents nitrogen.

Its philosophy is that plants need a continuous source of slow-release nitrogen along with smaller amounts of trace elements.

Rather than buying separate products such as HollyTone, PlantTone, TomatoTone, GardenTone, and RoseTone, the episode recommends focusing on the fundamental nutritional needs shared by plants.

Do Native Plants Need Fertilizer?

The answer in the episode is yes.

The show argues that every plant needs an energy source and that modern environmental conditions are different from those of a century ago.

Its basic formula is:

Food + water + mulch = better plant survival and performance.

Native status doesn’t eliminate a plant’s need for the resources required to grow and thrive.

Should You Add Sand to Clay Soil?

No.

The episode specifically warns against mixing sand into clay soil to improve aeration.

It explains that clay soil has very little air space and lacks organic material. Adding sand to that small pore structure can fill the existing spaces rather than creating the desired aeration.

The memorable comparison is that sand plus clay can produce an adobe-brick-like material.

The preferred solution is to build better soil with organic material rather than simply adding sand.

Can Vinegar Solve Every Gardening Problem?

Absolutely not, according to the episode.

High-acidity vinegar products can kill weeds, but the episode warns that they can also damage soil chemistry.

The recommendation is not to use vinegar as a universal weed or pest solution, particularly in lawns.

Will Neem Oil Cure Serious Scale Infestations?

The episode’s answer is deliberately blunt: don’t rely on Neem Oil for serious infestations.

The show cautions listeners about internet gardening advice, noting that something that is generally true isn’t necessarily the right solution for a specific problem.

Great Gardens’ philosophy is to use the most efficient, timely solution for the specific problem.

How Do You Know If Grass Seed Is Good?

This is one of the episode’s most important lawn-care questions.

The National Turfgrass Evaluation Program (NTEP) has evaluated turfgrass varieties since 1973.

Grass seed is evaluated according to factors including:

• Color
• Blade gloss
• Density
• Disease resistance
• Drought resistance
• Root-spreading ability
• Endophyte presence
• Maintenance requirements

The episode explains that professional growers and lawn-care experts place significant value on these evaluations because the performance can be demonstrated in the field.

Read the Back of the Grass Seed Bag

The episode strongly recommends reading the “Box of Truth” on the back of the bag rather than judging seed by the marketing on the front.

The goal is to see a very high percentage of actual grass seed rather than large percentages of inert material.

At Betty’s, the episode highlights blue seed labels as an indication of certification.

It also identifies Daybreak as a highly rated tall fescue with 99.78% pure seed, while Betty’s Super Bar combines three highly rated tall fescue varieties and Greenview’s Winning Colors contains four.

The message is simple:

Read the seed tag—not the front of the bag.

The Environment Is More Important Than the Seed

The episode makes a critical distinction between seed quality and growing conditions.

A quality seed planted in poor soil, fed with poor fertilizer, and managed poorly won’t produce a great lawn.

Instead, homeowners should evaluate the entire environment:

• Soil
• Sunlight
• Water
• Fertilizer
• Seed selection
• Weed control

The episode’s philosophy is summed up by the idea that you can’t expect great results from combining poor inputs and simply hoping for a great lawn.

Why Aren’t My Azaleas Blooming Heavily?

Azaleas may survive with limited nutrients, but abundant flowering requires considerably more resources.

The episode describes blooming as the point where a plant moves from simply surviving to thriving.

Late summer is particularly important because spring-flowering plants are setting their flower buds now.

If food, water, or mulch is insufficient, the plant may not have enough resources to carry flower buds through winter.

Feed, Water and Mulch Before Winter

Healthy spring bloom starts with the care you provide before winter.

The episode emphasizes that well-fed, well-watered, properly mulched plants are more capable of developing strong flower buds.

This is why late-summer plant care has consequences months later when spring arrives.

Don’t Forget Your Trees

The same nutritional philosophy applies to landscape trees.

The episode points out that trees growing in lawns may receive some leftover fertilizer from lawn applications, while trees planted away from lawns often receive very little fertilizer.

If you have an important tree in your landscape, ask:

When was the last time it was fertilized?

Long-term tree health depends on more than simply surviving from year to year.

What to Do in the Garden This Week

Show #157 closes with several timely late-summer and early-fall reminders.

Work on the Lawn Now

This is the time to:

• Kill weeds
• Core aerate
• Topdress
• Fertilize
• Repair weak lawn areas

Fall lawn renovation shouldn’t be delayed.

Apply Dylox for Grubs

The episode recommends treating sunny lawns and sunny beds with Dylox 24 Hour Grub Killer.

The product should be watered in, and the episode says treating now eliminates the need for a spring treatment.

Plant Mums

Nothing says fall quite like chrysanthemums.

The episode highlights large 8–9-inch potted mums at Betty’s and recommends watering them directly with a hose every other day for the first 2–3 weeks.

A water wand is preferred for directing water beneath the flowers and around the sides of the plant.

Avoid the “Umbrella Effect”

Plant foliage can deflect water away from the root zone.

This is described as the umbrella effect.

Flowering plants have an additional concern because water trapped among flowers can contribute to flower deterioration.

The episode recommends a water wand rather than a standard nozzle for more targeted watering.

Wait on Pansies

Don’t rush to plant pansies.

The episode recommends waiting until mid-September because pansies don’t perform well in the late-summer heat.

Watch for Mosquitoes

Mosquito activity is especially noticeable in the early morning and late afternoon—often when gardeners are outside trying to avoid the heat.

The episode recommends Green Armor on hats, shoes, and clothing to repel mosquitoes, gnats, no-see-ums, and chiggers.

Control Poison Ivy

For poison ivy and woods brush, the episode recommends Fertilome Weed Free Zone.

If you’ve already been exposed to poison ivy, it recommends Zanfel as a curative product.

The show also warns that conventional hornet and wasp sprays aren’t the appropriate solution for yellow jackets.

For yellow-jacket holes, it recommends treating the nest entrance after sunset with cypermethrin.

The Great Gardens Takeaway

Show #157 is ultimately about asking better questions.

Is the problem really the seed—or is it the soil?

Is the plant defective—or is it short on water?

Is the foliage damage fungus—or is the plant lacking food, water, and mulch?

Does the fertilizer need to be specialized—or does the plant simply need quality, slow-release nutrition?

Does a weed need a general treatment—or does it require specific identification?

The answer throughout the episode is to look at the environment first.

Build better soil, provide adequate water, use quality slow-release fertilizer, select the correct seed for the growing conditions, and identify problems accurately before treating them.

That’s the foundation of efficient, modern lawn and garden care.

Key Takeaways From Show #157

• Fall is the time to renovate lawns.
• Core aeration should precede soil improvement.
• Seed, fertilizer, and lime can work together.
• Wilt-Pruf improves spray coverage.
• Treat grubs at the right time.
• Avoid fall pruning of spring bloomers.
• Water is critical to plant survival.
• Quality soil improves everything.
• Read the grass seed tag.
• Choose NTEP-rated seed varieties.
• Native plants still need resources.
• Avoid outdated fertilizer formulas and practices.
• Think environment before blaming the plant.
• Fall care determines spring performance.