Gardening in Waitaki November 18th 2025.

The weather may still be unpredictable, but the warmer spells are nudging us fully into summer. Growth is racing ahead now, and that first flush of weeds is appearing just as quickly—deal with them before they set seed and spread further. Dahlias are surging into new growth. Make sure they’re in full sun with at least 10 cm of soil covering the tubers. When dahlias overwinter in the ground, the tubers often lift toward the surface, so top up with soil if needed before the plants get too tall. Daisy bushes and other spring-flowering shrubs can be pruned back now, especially if they’re taking up too much space. Trim them to the previous growth before seeds set and new wood hardens, which will keep them neat and encourage better summer displays. Summer bedding annuals are thriving in the warm soil—petunias, nemesia, lobelia, nasturtiums, salvias, marigolds, and the full array now in shops. These are ideal for brightening garden beds. For pots and baskets, choose varieties that stay relatively shallow-rooted. Geraniums are now readily available; plant them in a sunny, dry position and deadhead regularly to keep them flowering. Fuchsias and hydrangeas can go in now too—both prefer semi-shade and will pick up where your spring flowering shrubs, and peonies have finished. Those growing tuberous begonias will see tubers waking up. If you’re planting them for the first time, choose a sheltered, semi-shaded spot with good drainage. A little morning and late-afternoon sun is ideal. Plant tubers just beneath the surface, 20–30 cm apart, with the hollow (indented) side facing up. Keep the soil just slightly damp—never soggy—and avoid watering over the foliage, as mildew can set in easily. At the first sign of a white powdery patch, treat promptly with a fungicide. Feed with a balanced, fish-based fertiliser every two to three weeks. Buxus hedging may still be too soft to trim. When new growth snaps cleanly rather than bending, it’s ready for a tidy cut. Trimming too early results in a fuzzy edge rather than a sharp line. Lawns will benefit from a dose of fertiliser just before rain—there’s usually some on the horizon at this time of year. This helps build strong roots heading into the hotter months. To encouage deep roots on a new lawn a good soaking once a week is benificial rather than light sprinklings often. Veg Garden: The changeable temperatures will be showing up in the tomatoes' new growth. Cool nights can cause leaf curl or a bluish tint, but they typically recover with warmer weather. Try to avoid watering late in the day while temperatures are fluctuating. Leafy vegetables appreciate the odd chill as it delays bolting, so there’s a silver lining. Fruit should be progressing well. Consistent moisture and nutrients are essential while the fruit is forming. Berries and early plums will be the first to ripen—and the birds know it! Cover berry bushes and strawberry beds now, or you’ll find the birds have beaten you to them. Cheers, Linda