Get Your Lawn Ready: What to Do the Week Before September

September marks the start of serious lawn growth across New Zealand — but the week before it arrives is your best window to get ahead. A little preparation now means a healthier, thicker lawn all spring and summer. Here's what to do.

Check Your Lawn's Condition First

Before you do anything else, take a walk across your lawn and assess what you're working with after winter:

• Bare or thin patches — note where grass has thinned out or died off; these will need overseeding
• Thatch buildup — a thick, spongy layer of dead material sitting above the soil can block water and nutrients
• Compaction — if the ground feels hard underfoot, especially in high-traffic areas, aeration will help
• Moss or weeds — winter is prime time for moss to establish; deal with it before growth kicks in

Rake and Dethatch

Give the lawn a thorough rake to remove dead grass, leaves, and any thatch that's built up over winter. This opens up the surface, improves airflow, and lets light and moisture reach the soil. A spring-tine rake works well for most lawns; for larger areas, a dethatching attachment on a multi-tool power head makes the job much faster. We have a dethatcher you can hire, just check out our hire page for more information. 

Aerate If Needed

If your lawn is compacted — common in high-traffic areas or clay-heavy soils — now is a good time to aerate. Spiking or coring the lawn allows water, air, and nutrients to penetrate the root zone. Even a basic garden fork pushed in at regular intervals makes a difference on smaller sections.

Apply a Slow-Release Fertiliser

Late August is the ideal time to apply a slow-release lawn fertiliser. As soil temperatures begin to rise through September, the nutrients will be right there waiting for the grass roots. Look for a balanced NPK fertiliser with a higher nitrogen content to encourage that first flush of green growth.

Avoid fast-release fertilisers at this stage — they can push soft, weak growth that's more susceptible to disease.

Overseed Bare Patches

If you've got thin or bare areas, overseed them now before the main growth season begins. Lightly scratch the surface, apply seed, and keep it moist. With warming temperatures through September, germination should be reasonably quick.

Service Your Mower Before You Need It

Don't wait until the grass is long to discover your mower won't start. The week before September is the perfect time to:

• Check and change the oil if it's due
• Sharpen or replace the blade — a blunt blade tears grass rather than cutting it cleanly, leaving it vulnerable to disease
• Clean the air filter
• Check the spark plug
• Fill with fresh fuel — old fuel left sitting over winter can cause starting issues

If your mower needs a service or you're thinking about an upgrade before the season hits, get in touch with our team — we'd rather sort it now than have you waiting in a queue in October.

The First Mow: Always Cut Higher Than You Think

This is the most important rule of spring lawn care, and the one most people get wrong.

Your first mow of the season should always be set higher than your normal cutting height.

Here's why: grass coming out of winter dormancy has shallow root systems and limited energy reserves. Cutting it too short too soon — a common mistake — stresses the plant, removes too much leaf area, and slows recovery. It can also scalp any uneven areas and expose bare soil to weed seeds.

The rule of thumb: never remove more than one-third of the grass blade in a single mow. For most NZ lawns, that means setting your deck to its highest or second-highest setting for the first cut of spring.

As growth strengthens through September and into October, you can gradually lower the cutting height back to your preferred level — but do it in stages, not all at once.

A sharp blade at a higher setting will give you a clean, healthy cut that encourages the grass to thicken up rather than struggle.

A Quick Pre-September Checklist

• Walk the lawn and assess condition
• Rake and dethatch
• Aerate compacted areas
• Apply slow-release fertiliser
• Overseed bare patches
• Service your mower (oil, blade, filter, spark plug, fuel)
• Set your mower deck to a higher cutting height for the first mow

Get these steps done in the week before September and your lawn will be in the best possible shape to take advantage of the growing season. If you need help with equipment — whether it's a service, a new blade, or an upgrade — the team at Franick Outdoor Power Specialists is here to help.