Gardening in Waitaki

Gardening in Waitaki
Weekly garden blog

Wednesday, August 13, 2025

Gardening in Waitaki August 13th 2015

Early spring is peeping out from winter, despite the harsh frosts. Snowdrops are always the first to push through the frost, followed by winter roses, early camellias, daffodils, and now plum blossom. If we don’t get a good dollop of rain soon, shallow-rooted shrubs and trees—such as rhododendrons, camellias, azaleas, and maples—will need watering to support their new growth. On mild days, it’s tempting to get planting and sowing. Remember that seeds need warmth to germinate, so protect them until the soil reaches a suitable temperature. Outdoors, sowing is best left until frosts are ending and bees are active. Plants budding up for flowers can be given a gentle liquid feed now to keep root growth strong. Diluted worm or comfrey tea is ideal for soft new growth, but any liquid food at a weak dilution will help. Roses benefit from liquid manure diluted to the colour of weak tea, applied around the roots. Finish all rose pruning by month’s end. Weeds & Invasive Plants: Weeds are on the move. With the ground still soft, hand-pulling or hoeing is easy—remove them before they seed. Now is the time to deal with invasives such as ivy, aluminium plant (Lamium), couch grass, convolvulus, and bindweed. Hydrangeas: New green growth at the base means pruning time. Cut all woody stems that flowered last summer back to the second bud from the bottom. Leave all other stems, as they will carry the new flowers. Pink hydrangeas prefer alkaline soils (pH > 8.5), while blue ones need acidic soil. To maintain strong blue blooms, grow in a large pot with acid potting mix if your garden soil produces pink flowers. Planting & Pruning: Keep planting roses, peony roses, and gladioli until September. Plant lilies immediately; they must not dry out as they make roots year-round. Cut back leggy lavatera and buddleia, they will bounce back quickly. Comfrey – A Garden Powerhouse: Comfrey’s deep roots draw nutrients from well below the soil’s surface, storing them in the leaves. These nutrients, especially potassium, promote flowering and fruiting. To make comfrey tea, harvest leaves (removing flowers and tough stems), chop them, and pack them tightly into a lidded, watertight container. Weigh them down with a brick or stone, then check every few weeks. The breakdown process produces a strong-smelling brown liquid—collect and store it in bottles in a cool, dark place. Refill the bucket with fresh leaves. Plant comfrey where it can spread freely, away from main garden beds, as it can become invasive. Lawns & Moss Control: Moss killers are a short-term fix—address the cause for lasting results. Common issues include: Waterlogging , Poor feeding (light green grass), Acidic soil (test and lime if needed). Shade from trees or shrubs, mowing too close. Sandy soil (improve with compost/humus) , Compaction from heavy use (aerate in autumn), DIY soil test. Pouring white vinegar over soil (fizz = alkaline). If no fizz, mix soil with water, then add baking soda (fizz = acidic). Small patches can be treated with sulphate of iron—moss will blacken, then rake out and re-seed. Apply your first spring lawn feed before rain is due. Vegetables: Harvest winter crops while they’re still at their best. Fold cauliflower leaves over and tie to protect from frost and keep florets tight. Prepare asparagus beds deeply with compost and good drainage; existing beds should be weeded carefully to avoid damaging crowns. Plant sprouted potatoes now for an early crop—try laying them on pine needles or comfrey leaves for extra nutrients as they decompose. Inland gardens may still be frozen, but you can prepare beds by digging in compost or humus. Fruit: Soak and mulch fruit trees and berry bushes—they have a lot of growing ahead. Cheers, Linda.
Asparagus popping through.