With the weather heating up, it's time to get water-wise. It's also time to get your garden looking ship-shape for Christmas and a summer spent outdoors. We've got all the best tips, tricks and expert advice to get your garden looking delightful in December.


Skip to what to plant in the garden in December

Skip to what plants need feeding in December

Skip to which plants to prune in December

Skip to garden pests, diseases and weeds to look out for in December

Skip to December's general lawn and garden care tasks

Skip to your December garden centre shopping list


What's flowering in Sydney gardens in December?

What to plant in the garden in December

  • Fill your garden with aster, marigold, petunia, phlox, salvia, sweet William, verbena and zinnia.
  • December is a great time to plant container-grown bougainvillea, mandevilla, passionfruit and wisteria.
  • Enjoy fresh produce from your garden by planting beans, beetroot, carrot, Chinese cabbage, lettuce, radish, silverbeet and tomato. Don't forget to harvest regularly to encourage more growth!

Which plants to fertilise in the garden in December

  • Boost houseplants with Fair Dinkum Fertilizers Seaweed Gold Liquid Seaweed - but before applying, place plants outside under cover, so the smell doesn’t fill the house. You can leave the plant outside for the day.
  • Feed your ferns and palms a suitable slow-release fertiliser. Check the strength of the fertiliser before applying, as it can be too strong for particular plants.

Which plants to prune in the garden in December

  • Trim any spring-flowering plants which have finished blooming to keep your garden looking tidy.
  • Snip off old blooms from rose plants which have finished flowering and fertilise well.
  • If your hedges are looking a little raggedy around the edges (common after spring growth!), now’s the time for a quick trim.
  • Feeling generous? Cuttings of plants from your garden can make really lovely gifts for neighbours and friends!

Garden pests, weeds and diseases to look out for in December

  • Check azaleas for azalea lace bug. A dull mottling or silvering of azalea leaves are signs of an attack. Yates Baythroid will fix the problem.
  • Apply snail bait such as Multiguard Snail & Slug Killer Pellets liberally to prevent slugs and snails munching on new growth. Always stick to package instructions and keep the bait out of reach of young children and animals. Alternatively, spray the area with copper oxychloride or use a homemade beer snail trap.
  • Spray caterpillars on edibles and ornamentals with Nature's Way Caterpillar Killer Dipel. You can also use Nature's Way Vegetable Dust Derris, but wait at least one day before harvesting edibles.
  • Protect azaleas and fuchsia from two-spotted mite with a systemic insecticide.
  • Rust, mildew, black spot and other fungus on roses, ornamentals and veggies should be sprayed with a fungicide.
  • Love berries? So does the local bird population! Keep your ripening crop out of harm’s way with netting or mesh, and check it regularly in case any critters get stuck.

General garden and lawn care in December

  • Feed your hungry lawn. At this time of year we recommend the Scotts Lawn Builder range, as it doesn’t need to be watered in like other lawn fertilisers. Want super-quick results? The  Extreme Green formula will green up your lawn in 3 days! For more advice on reviving your lawn in summer, click here.
  • As hot, dry weather continues, it’s important to do what you can to help your plants thrive with less water. Keep all beds, pots and containers well-mulched to help retain moisture. Use soil-wetters on hydrophobic soils, try water-saving crystals in new plantings, and train your plants to withstand longer dry periods by watering deeply as needed and avoiding frequent, light watering.
  • Water citrus and feed with specially formulated citrus food. Mulching around the trees will help to retain soil moisture.
  • Pot some annuals for late summer colour and plant annuals in the garden to fill any bare spaces.
  • Harvest your veggies frequently. Regular picking encourages more growth.
  • Place sand in saucers under potted plants to stop mosquitoes breeding there.

Your December Garden Centre shopping list