Top 10 Garden Maintenance Mistakes (and How to Avoid Them)

Keeping your garden healthy in the Illawarra’s coastal climate takes more than watering and mowing. Here are the most common garden maintenance mistakes homeowners make — and how to avoid them for a greener, more resilient landscape.

Why Proper Garden Maintenance Matters

A beautiful garden is more than just good luck: it’s the result of consistent care and knowing what not to do. In the Illawarra region, where warm summers, salty air, and periodic rainfall create unique growing conditions, even the smallest maintenance mistake can affect your garden’s long-term health.

A few adjustments in watering, pruning, mowing, and soil care can transform tired lawns and gardens into lush, thriving spaces. Below, we’ve outlined the top 10 garden maintenance mistakes we see most often — and how you can avoid them to keep your landscape in peak condition year-round.

1. Overwatering or Underwatering

Finding the right balance is key. Many Illawarra homeowners overwater their lawns and plants, thinking more water means better growth. In reality, overwatering can suffocate roots and encourage fungal problems, while underwatering leads to dry, brittle grass and wilting plants.

Avoid it by:

• Watering deeply two to three times per week instead of shallow daily watering.
  
• Adjusting watering based on weather — less after rain, more during dry spells.
  
• Installing smart irrigation systems to automate efficient watering.
  

Learn more in our post on Irrigation and Watering Tips for a Healthy Lawn.

2. Cutting Grass Too Short

Many people mow their lawns too low in an attempt to reduce mowing frequency. Unfortunately, this weakens your lawn by removing too much of the leaf blade, reducing its ability to photosynthesise and protect roots from heat.

Avoid it by:

• Following the one-third rule: never cut more than one-third of the blade’s height.
  
• Keeping warm-season grasses (like Buffalo and Kikuyu) between 30–50mm high for best results.
  
• Sharpening mower blades regularly for a clean, even cut.

Learn more in our post on The Best Mowing Schedule for NSW Lawns: Seasons & Frequency.

3. Ignoring Soil Health

Healthy soil is the foundation of a healthy garden. Over time, compacted or nutrient-poor soil can prevent roots from accessing water and oxygen, leading to patchy lawns and stunted growth.

Avoid it by:

• Aerating your lawn at least once a year.
  
• Adding compost or organic fertiliser to boost microbial activity.
  
• Testing pH levels and adjusting with lime or gypsum if needed.
  

4. Forgetting to Fertilise (or Overdoing It)

Fertilising is essential, but timing and quantity matter. Too much can burn your grass and plants, while too little limits growth and colour.

Avoid it by:

• Applying fertiliser at the start of spring and again in early autumn.
  
• Using a slow-release, lawn-specific fertiliser.
  
• Following the manufacturer’s instructions to prevent nutrient overload.
  

5. Poor Pruning Technique

Pruning helps plants stay healthy, but cutting incorrectly or at the wrong time can stress them and reduce flowering.

Avoid it by:

• Using clean, sharp tools to prevent disease spread.
  
• Pruning just after flowering for most shrubs.
  
• Removing no more than one-third of a plant’s mass at a time.
  

If your garden’s feeling overgrown, get in touch with us for expert pruning and hedge trimming to keep everything looking neat and healthy.

6. Neglecting Lawn Edges

Edges are often overlooked, but they make the difference between a tidy yard and a neglected one. Over time, grass and weeds can creep into garden beds, making your lawn appear messy.

Avoid it by:

• Using a half-moon edger or string trimmer after each mow.
  
• Installing metal or stone edging for long-term control.
  
• Scheduling regular edging as part of your maintenance routine.

Read our post on How Regular Garden Maintenance Protects Your Investment.

7. Planting Without Considering Sunlight and Drainage

Not all plants thrive in the same conditions. Many garden issues start with placing the wrong plants in the wrong spot.

Avoid it by:

• Observing how much sunlight different areas of your garden receive.
  
• Grouping plants by their water and light needs.
  
• Choosing native or drought-tolerant species that suit Illawarra’s coastal environment.
  

For instance, Grevillea, Kangaroo Paw, and Lomandra perform beautifully in sunny, well-drained areas, while ferns and shade-loving palms suit sheltered corners.

8. Failing to Control Weeds Early

Once weeds take hold, they compete with your grass and plants for nutrients and water. Leaving them too long makes removal harder and allows them to spread.

Avoid it by:

• Hand-pulling or spot-treating weeds as soon as they appear.
  
• Applying pre-emergent weed control before spring.
  
• Keeping your lawn dense and healthy to naturally suppress weed growth.

Read our post on Mulching for Moisture Retention and Weed Control.

9. Overlooking Seasonal Adjustments

Gardens aren’t static: they change with the seasons. What works in summer won’t necessarily suit winter.

Avoid it by:

• Adjusting your mowing height in cooler months to protect root systems.
  
• Fertilising and aerating before the growing season.
  
• Pruning in winter to encourage new growth in spring.
  

Learn more in our posts:

‍Seasonal Lawn & Garden Planner for NSW: What to Do Each Quarter

‍The Best Mowing Schedule for NSW Lawns: Seasons & Frequency.

10. Doing Everything Yourself (Without the Right Expertise)

While DIY garden care can be rewarding, many property owners underestimate how much expertise is needed for professional results. Incorrect mowing, irrigation setup, or soil treatment can cause more harm than good.

Avoid it by:

• Seeking expert help for complex tasks like irrigation, lawn restoration, or large-scale pruning.
  
• Partnering with professionals who understand local soils, grasses, and weather patterns.
  

At Brooksie’s, we combine experience, local knowledge, and high-quality equipment to deliver reliable garden maintenance across Wollongong and the surrounding areas. Get in touch with us today for a free quote.