Gardening in Waitaki August 20th 2025

As August nears drawing to a close, winter loosens its grip—though recent frosts remind us to stay cautious. Seedlings are quivering in the cold but, with frost cloth protection, are hanging on and soon ready to pot on. Growth has been slow, but weeds such as chickweed and bidibid are thriving—pull them now before they set seed. Elsewhere, violets are filling gardens with fragrance. Camellias, rhododendrons, and shallow-rooted shrubs may show yellowing from nitrogen deficiency after winter—correct with slow-release fertiliser and compost. Keep frost cloth handy for tender plants, mulch after spring rains to lock in moisture, and feed generously. Plants are pouring energy into new growth. The work you put in now with feeding, mulching, and tidying will carry your garden strongly into the season ahead. Magnolias take centre stage, their sculptural bare branches covered in stunning blooms. They thrive in acid soils alongside azaleas, rhododendrons, and camellias. Garden centres are full of choices: compact Magnolia Billowing Cloud (3m × 2.5m) for small gardens, or the taller Charles Raffill (7m × 5m) for larger spaces. Lavenders can be cut back as new growth appears. Old, woody bushes can be trimmed hard to encourage fresh shoots—if they don’t respond, replace them. New plants just need a light haircut, compost, and lime. Climbers are in bud now, so trim carefully. Delay pruning jasmines until frosts are over. Roses are moving fast—feed now to set them up strongly and reduce the need for spraying later. Many other perennials and shrubs benefit from feeding too, but avoid heavy fertiliser on South African and Australian natives. Hostas can still be divided before leaves emerge, while dahlias can be planted in sunny, free-draining spots. Ornamental grasses should be cut back now, and shrubs tidied, though take care with climbers and spring-flowering plants already in bud. Lawns are greening up and need attention after winter. Moss thrives in shaded, compacted, or acidic soils—apply sulphate of iron, rake out once blackened, then aerate and feed. A good spring start will help lawns withstand the predicted dry summer. Vegetable beds are waking up too. Plant seedlings later in the day when sun is softer, but water in the morning so soil warms before night. Sow green crops (mustard, lupine, barley, wheat) in unused areas, and dig them in while still lush and soft. Early seed potatoes can be planted now—protect against late frosts. Continue sowing seeds under cover, using soil, compost, and seed-raising mix. Cover trays with glass or plastic, allowing airflow, and feed seedlings weekly with diluted worm tea. Fruit trees and shrubs need a boost—apply potash-rich fertiliser to encourage strong crops. Plant deciduous trees and berry canes by early September. Thin raspberries by removing old and weak canes. Citrus, especially lemons, will appreciate a feed of citrus fertiliser and a good soak. Keep trunks free of grass and weeds, mulch well, and time spraying for dull days when bees aren’t active.

Cheers, Linda