Gardening in Waitaki May 13th May 2026

The chill of late autumn is noticeable now in early mornings and nights here in North Otago, but there is still enough warmth in the ground for plants to continue growing steadily. There is still plenty to do in the garden, and these crisp sunny days make it a rewarding time to be outside preparing for the seasons ahead.Compost season is well underway, and my ready compost is disappearing quickly as it is shovelled generously over cleared garden beds in preparation for winter. Pea straw was used to follow in my past large garden, but where I am now, the wind would not allow it to stay put.  Some gardeners will still be waiting for the last of the leaves to fall before finishing the mulching. Autumn leaves are far too valuable to waste, and there are many ways to make use of them. Some are being added to compost heaps while others are being turned into leaf mould, which is wonderful for improving soil texture and adding humus back into the garden. To make leaf mould, shred leaves first with the lawn mower, as whole leaves break down far too slowly. Layer them into bins or large bags with a sprinkling of nitrogen-rich material, such as grass clippings or a handful of urea, between layers, and water lightly as you build. Left over winter, this will break down beautifully and be ready for spring use. My well-grown seedlings have been potted up before colder nights arrive. They have come directly from seed trays, frost cloth will soon cover them and will likely remain in place until spring. Winter colour for the garden: Calendulas, primulas, pansies, polianthus, ornamental kale, Leptospermum, azaleas, daphnes, Chimonanthus praecox (winter sweet)  and those special leucodendrons.Dahlias: Reminding you once again, cut back, dig, and divide for late spring planting. Label clumps by colour and store in cardboard boxes in a dry place. Fill gaps with winter annuals, such as wallflowers and poppies.  Ericas: Trim spent summer flowers to maintain compact growth. Avoid lime and fertiliser; they thrive in dry, sunny soil. Ground cover varieties are low-maintenance and will now be budding for winter colour. Bearded Iris and Freesia: Keep compost and mulch away from exposed rhizomes and bulbs to prevent baking in the sun.  Perennials: Divide overgrown clumps to fill gaps or pot up for later planting. Cover beds with compost to encourage root growth and insulate through winter.  Peony Roses: Plant or shift this month, taking care not to damage tuber shoots. Cuttings: Move trays to a light, warm spot for winter growth and water less frequently, at the start of the day.Pot Plants: Reduce watering and move away from cold glass as night temperatures drop.  Lawns are finally slowing down, and bare patches are best left now until spring sowing. Lime and gypsum can still be applied to help soften compacted clay soils and improve lawn condition over time. Grass grubs will be slowing down the eating of grass roots now, as larvae, they eat to fuel their transition into the brown night beetle. This process takes about 12 months. The most damage done to lawns is from February to May. Rake out patches of dead lawn ready for re-sowing now on the coast while the ground is still warm, or wait until spring. An earth-friendly way to eradicate grass grub is nematodes. Beneficial Cseek out and kill grubs and other soil-inhabiting insects. They come on a sponge (invisible to the naked eye) that you soak in water, put in a sprayer and spray your dirt or lawn. They will multiply over time and continue to kill grubs. A retail outlet for nematodes for sale is: https://www.bioforce.co.nz/products/nematop.html Vegetable garden: Plant snow peas, pak choi, kale, broccoli, cauliflower, and beetroot. Seeds: Sow baby spinach in kitchen window containers for winter greens. This is the last month to sow carrot seeds; use onion sets rather than seeds now for better results. Clear finished summer vegetables or dig in leafy crops. Add manure-enriched compost and lime to heavily cropped soil, and leave the soil exposed to winter frost. Fruit: Apples and late peaches will still be ripening on trees to enjoy. Leave winter fruit tree pruning for July through August, or before buds begin to swell. Not all fruiting plants require an annual prune, and some new dwarf cultivars of apples, peaches, apricots and nectarines have been bred to eliminate the need for annual pruning and maintenance. I will go further into this closer to the time. Cheers, Linda