May is a key transition month in the New Zealand garden. While growth above ground begins to slow, what’s happening in your soil is just as important—if not more so.

This is the time to shift your focus from feeding plants to building healthy, resilient soil.

With cooler temperatures and increased rainfall, nutrients can leach away and soil structure can start to break down. Preparing your soil now ensures it holds together through winter and is ready to support strong growth when spring arrives.

One of the most effective ways to do this is by adding humates.

Humates are a concentrated source of organic carbon that improve soil structure, increase moisture retention, and help lock in nutrients. They also support beneficial microbial life—something that continues working quietly through the colder months.

Now is the perfect time to mulch garden beds and incorporate humate into the soil, whether around established plants, trees, or empty beds. Think of it as building a reserve of nutrients and structure that your garden can draw on later.

If you’re sowing green manure crops like lupins, oats, or mustard, adding humate at planting will give them a stronger start. When these crops are turned back into the soil, you’ll be adding organic matter that’s already active and improving your soil from within.

Featured Product: Premium Organic Humate

Dave’s Premium Organic Humate is an ultra-concentrated, BioGro certified soil conditioner made from ancient organic material formed over millions of years.

Because of its concentrated nature, it’s up to 20 times more potent than regular compost—so a small amount delivers a big impact.

It works by improving soil structure, increasing water retention, and reducing the leaching of valuable nutrients—particularly important during the wetter winter months. It’s especially effective in poor soils, helping sandy ground hold nutrients and improving drainage and structure in heavy clay.

Apply it directly into garden beds, mix it through compost, or use it when planting vegetables, bulbs, or trees. Over time, it builds a richer, more balanced soil that supports stronger root systems, better flowering, and improved yields.

Suitable for lawns, vegetables, fruit trees, flowers, and pasture, it’s a simple way to lift the performance of your entire garden—naturally and safely.

What to Plant in May in New Zealand

There’s still plenty you can grow through the cooler months:

• • • Onions – Brown, red, and spring onions all establish well now.v
    • Shallots – A reliable long-season crop to plant this month.
    • Broad Beans – Hardy and great for winter growing, while also fixing nitrogen into the soil.
    • Peas – Snow peas and sugar snap peas thrive in cooler conditions.
    • Spinach & Silverbeet – Reliable, nutrient-dense greens that perform well through winter.
    • Lettuce – Choose cold-tolerant varieties like Cos or Buttercrunch.
    • Carrots & Beetroot – Slower growing, but ideal for winter harvest.
    • Cabbage, Broccoli, Cauliflower – Brassicas love the cold and benefit from fewer pests.
    • Garlic – Traditionally planted in May; plant cloves 5–7cm deep, pointy end up.

Preparing Your Garden for Winter

Alongside planting, May is about setting your garden up for the months ahead.

Start by clearing out spent crops and adding organic matter such as compost. This helps improve soil structure and feeds the microorganisms that keep your soil alive.

Adding humate at this stage helps stabilise nutrients, improve moisture retention, and protect your soil from winter conditions. It acts like a buffer—keeping everything balanced while your garden rests.

Mulching is another key step. A good layer of mulch helps regulate soil temperature, reduces moisture loss, and protects against heavy rain.

A Long-Term Approach to Better Soil

Humates aren’t a quick fix—they’re a long-term investment.

By improving cation exchange capacity (C.E.C.) and helping buffer pH fluctuations, they create a more stable and fertile growing environment. That means stronger roots through winter and better nutrient uptake when growth kicks off again in spring.

🌿 Tip of the Month

Add humate whenever you’re planting anything new. Even in cold soils, it helps roots establish faster, improves nutrient uptake, and supports beneficial soil life.

As you prepare your garden for winter, remember—the work you do now beneath the surface will determine what you see above it in spring.

A little effort, and a little humate, goes a long way.

Happy Gardening,
Dave’s Garden Products