Gardening in Waitaki September 17th 2025

Magnolia Starwars

As I write these garden notes, we are still waiting for a good drenching spring Rain to give lawns and gardens a real boost, but blossom and magnolias are lighting up North Otago. Bees are humming again, and spring planting is in full swing. Blossoms & Trees: If you’re planning new gardens, now is the time to choose blossom trees. Prunus come in many forms, from tall grafts with clear trunks (great for driveways and walkways) to low, spreading forms for lawns. Always consider eventual height, spread, and root system before planting close to houses or paths – falling blossom, sticky underfoot, and autumn leaves can be a nuisance on paved areas. There’s a tree for every spot, so seek advice to match your choice to your garden. Weeds & Beds: deal with weeds early by hoeing or hand-pulling before they set seed. If you prefer not to use sprays, try natural alternatives that dehydrate weeds on hot sunny days. Annual weeds are easily managed, but perennials like convolvulus or couch will need persistence. Salt dissolved in hot water is an inexpensive, effective control for many annual weeds, but it is not systemic, so if washed off, it will need to be reapplied. Planting & Pots: This is the perfect time to sow seeds for summer colour, directly in the ground or in trays with a layer of seed-raising mix on top of potting mix. Transplant once seedlings have developed strong roots and hardened before planting outside. For baskets, choose shallow-rooted plants such as pansies, lobelia, small petunias, nemesia, or dwarf sweet peas, with slow-release fertiliser and water crystals added. Established potted shrubs may be rootbound – remove from pot, trim back roots, and re-pot with fresh mix and fertiliser. Roses and hydrangeas need deep pots to keep roots cool; lining pots with tin foil (shiny side out) helps prevent overheating. Ensure all potted plants have excellent drainage and consistent water. Shrubs & Flowers: Trim back winter and early-spring-flowering shrubs before new growth gets away. Layer azaleas, rhododendrons, magnolias, and other low growers by pegging a branch into the soil to root. Stake tall perennials such as delphiniums, peonies, asters, and phlox now, before they shoot up. Lavenders are making new growth; give them a dressing of lime, and trim lightly. Replace very woody, tired plants with fresh ones. Bougainvillea should be cut back once new buds appear, then fed and watered to encourage strong flowering. Tubular begonias can be set into damp sawdust or compost until sprouting, then potted on, but once in growth, never let them dry out until flowering finishes. Roses are leafing up, and aphids will appear soon. Rub them off by hand or leave for birds and predators; if spraying, wait until foliage hardens. Lawns: Feed established lawns just before or during rain to keep them lush. New lawns should be sown thickly to outpace weeds. Avoid feeding very new lawns; they need to push roots deep for strength. Keep mower blades high in spring to thicken grass. Vegetables: In the vegetable garden, plant lettuces in fortnightly intervals, get peas and climbing beans into sunny, manured ground with supports, and sow corn and pumpkins, protecting seedlings from frost. Keep mounding potatoes as shoots appear, and cover if frosts threaten. A quick potato guide: Waxy (boiling, salads, soups): Draga, Frisia, Nadine. All-purpose: Desiree, Rua, Vivaldi. Floury (mash, roast, chips, baking): Agria, Ilam Hardy, Red Rascal. Herbs are putting on fresh growth, prune back old stems, enrich the soil with compost and lime, and pick often to keep them producing. Fruit: Strawberries and rhubarb are stirring, mulch with manure-enriched compost, then straw, pine needles, or untreated lawn clippings. Blackcurrants can still be pruned; mulch with compost and potash afterward. September is full of promise: blossom, bees, new growth, and the thrill of planting for the season ahead. Take time to enjoy spring and all it offers, even between the showers, frosts, and the inevitable winds! Cheers, Linda

Root prunning potted plant.