Waikato Lawn Care Calendar: What To Do Month By Month

In the Waikato the lawn year runs like this: sort moss and compaction in August, feed and start weekly mowing from late September, coast through a dry January, sow seed and feed again in March, then keep cutting through winter at a higher setting. Everything else is detail.

Most lawn advice online is written for the northern hemisphere, so the months are six out of six wrong. Follow it here and you feed in the cold, sow seed into a dry January and scalp the lawn just as winter starts.

We’ve mown Hamilton lawns since 2007. This is the calendar we actually run our own year by, timed to Waikato weather, Waikato clay and the grass that grows here.

The Quick Version

Spring: September, October, November

September — wake it up

The soil is warming but it’s still wet. The first cut of the season should be a tidy-up, not a scalping. Take the top off, then bring the height down over the next two or three cuts rather than all at once.

This is the month to deal with anything winter left behind: moss, bare patches, and the squelchy areas that never dried out. If the ground still holds a footprint after rain, that’s compaction, and aeration is the fix.

The first feed goes on once the grass is clearly moving, usually the last week of September. Not before. Cold grass can’t use fertiliser.

October — the flat out month

October is the fastest growth of the whole year in Hamilton. Warm soil, long days and reliable rain. Lawns that looked dead in July go mad.

Mow every seven to ten days. Stretch it to three weeks and you’ll be cutting off more than a third of the leaf, which yellows the lawn and stresses it right when it should be thickening up.

Broadleaf weeds are growing hard too, which makes October the best month to spray them. They take the chemical up fast while they’re growing.

November — hold the pace

Still weekly, or thereabouts. Start lifting the mower height a notch towards the end of the month. Longer leaf shades the soil, holds moisture and gets the lawn ready for a dry January.

Kikuyu lawns hit their straps now and start running across paths and into garden beds. Edges need doing every cut, or the lawn creeps a hand’s width into the border by Christmas.

Summer: December, January, February

December — height up, clippings down

Mower up another notch. A longer lawn survives dry spells far better than a short one, and it’s the cheapest drought protection there is.

Leave the clippings on when you can. They break down, feed the lawn and hold moisture. The one exception is a cut that has got away on you — heavy clumps sitting on the surface smother the grass underneath.

January — do less

Hamilton usually gets a dry run through January and February. Growth slows right down and a fortnightly cut is normally plenty.

Don’t fertilise a lawn that is going brown from dryness. You will burn it. Don’t sow seed either — it will germinate and die in the same week.

Brown does not mean dead. Ryegrass goes dormant and comes back with the rain. Kikuyu barely notices the dry at all.

February — watch for the turn

Still slow, still fortnightly. Once real rain arrives at the end of the month the lawn takes off again, and that is your cue for the autumn jobs. Any bare patch you can see now is a patch to seed in March.

Autumn: March, April, May

March — the most underrated month of the year

If you only do one big job on your lawn all year, do it in March. Warm soil, cooler air, reliable rain and fewer weeds competing. Seed sown now has a full autumn to establish before winter.

The second feed of the year goes on this month. It builds root reserves that carry the lawn through winter and hand you a better spring.

March is also fine for aeration if you missed the spring window.

April — slow it down

Growth eases off. Every two to three weeks is usually right. Start lifting the mowing height again for winter, and don’t drop it back down until September.

Leaves start dropping. Get them off the lawn before they mat down — a wet layer of leaves blocks the light and leaves a yellow dead patch that lasts until spring.

May — last real tidy-up

One good cut before the ground gets properly soft, plus a full edge and a leaf clear. Do that and the lawn looks presentable right through to August with very little work.

Winter: June, July, August

June and July — keep ticking over

Hamilton lawns don’t stop growing over winter, they just slow to a crawl. A cut every four to six weeks keeps things in shape.

Cut high. Winter is the worst possible time to scalp a lawn: short grass lets light onto the soil, which is exactly what moss and weeds want.

Stay off saturated ground. Waikato clay compacts under a mower, or under kids and dogs, when it is waterlogged. Wheel ruts made in July are still there in November.

August — the month that sets up the year

August decides what your lawn looks like in October. Spray moss now, rake it out, and the bare ground fills in with spring growth instead of sitting empty for months.

It is also when to book a mowing service if you want one. Every lawn contractor in Hamilton fills up in the first fortnight of September. Getting it sorted before the rush is the difference between starting the season on schedule and waiting three weeks.

A Few Things That Are Specific To Hamilton

• Clay under everything. A lot of Hamilton sits on heavy clay. It holds water in winter and sets hard in summer, so aeration does more here than it would on light sandy soil.
• New subdivisions behave differently. Rototuna, Flagstaff and Huntington are cut and fill sections — thin topsoil over compacted subsoil. They dry out faster in January and stay wetter in July than the older streets.
• Older west side lawns hold more kikuyu. Around Nawton and Dinsdale, deeper soil and bigger sections mean kikuyu is common, so those lawns brown off in winter and grow hardest in February.
• Damp mornings near the river. Sections close to the Waikato River sit wet longer on winter mornings, and that is where we see moss turn up first.

Frequently Asked Questions

When should I start mowing my lawn in the Waikato?

You never really stop. Hamilton lawns keep growing slowly through winter, so a cut every four to six weeks from June to August keeps them tidy. Real growth starts once the soil warms in late September, and from October to December most Hamilton lawns need mowing every seven to ten days.

When is the best time to fertilise a lawn in Hamilton?

Two feeds a year covers most Hamilton lawns: one in late September or early October when the soil has warmed and growth is starting, and one in March as the heat comes off. Feeding in the middle of winter is wasted money, because cold grass can’t use it.

When should I sow lawn seed in the Waikato?

Autumn is the best window, roughly March to April. The soil is still warm, the rain is reliable and there are fewer weeds competing. Spring sowing in October also works, but the seedlings have to survive the first dry spell, so they need watering.

When should I aerate a Waikato lawn?

Early spring, around September and October, or autumn in March. The ground is soft enough for the tines to get in and the grass is growing fast enough to recover. Waikato clay compacts badly, so once a year is plenty for most lawns and well worth doing on any area that squelches after rain.

How often does a Hamilton lawn need mowing in summer?

Every seven to ten days through October and November while growth is at its peak. In January and February growth slows in dry weather and a fortnightly cut is usually enough. Kikuyu lawns keep pushing through the heat and often still need mowing weekly.

Should I mow my lawn in winter in Hamilton?

Yes, just less often and a notch higher. A lawn left completely alone from June to September comes into spring long, matted and patchy, which is exactly the opening moss and weeds need. One cut every four to six weeks over winter keeps it in shape. We mow all year round for that reason.

Happy mowing!