Care guides › Brisbane › December
December in the Brisbane garden
Early summer in Brisbane. Subtropical: no frost, a dry spring, then a wet summer. Here is what needs doing this month, with the essentials first.
- What to harvest 30
- Feeding 5
- Pruning and deadheading 34
- Watering 19
- Pests and diseases to watch for 18
- Frost and weather 2
- Tidying up 6
What to harvest in December
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Tomato
Pick as fruit colours; it finishes ripening indoors
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Lettuce
Pick outer leaves or whole heads
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Carrot
Pull from about 12 weeks after sowing
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Cucumber
Pick young and often
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Capsicum
Pick green, or leave to colour fully
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Zucchini
Pick at 15-20 cm, every few days
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Runner Bean
Pick pods young and often
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Onion
Lift once the tops fall over and yellow
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Garlic
Lift when half the leaves have yellowed
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Potato
Dig once the tops die back
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Sweetcorn
Pick when silks brown and kernels squirt milky juice
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Eggplant
Pick while the skin is still glossy
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Plum Tree
Pick when soft at the stalk end
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Blueberry Bush
Pick berries a few days after they turn blue
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Raspberry Cane
Pick every couple of days
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Basil
Pick often; take the lot before winter
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Strawberry
Pick fully red fruit every day or two
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Silverbeet
Pick outer leaves as needed
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Warrigal Greens
Pick the soft tips often; blanch before eating
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Lemon Myrtle
Pick leaves as you need them; they dry well
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Rosemary If you have time
Snip sprigs as needed; it keeps it bushy
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Thyme If you have time
Snip sprigs as needed
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Mint If you have time
Pick often to keep it leafy
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Sage If you have time
Pick leaves as needed; best before it flowers
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Chives If you have time
Snip leaves to 5 cm; the flowers are edible too
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Parsley If you have time
Pick outer stems first
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Dill If you have time
Pick fronds, then seed heads as they brown
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Fennel If you have time
Pick fronds as needed
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Oregano If you have time
Pick sprigs; dry a bunch before it flowers
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Lemon Verbena If you have time
Pick leaves for tea as needed
Feeding
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Rose
Rose fertiliser after the first flush
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Blueberry Bush
Azalea and camellia (acid) fertiliser
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Summer vegetables If you have time
Liquid feed every 2 weeks while cropping
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Herbs If you have time
A little liquid feed in spring and midsummer
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Annual flowers If you have time
Liquid feed every 2-3 weeks while flowering
Pruning and deadheading
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Lavender
Cut off spent flower stems and a little foliage; not into bare wood
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Rosemary
Trim after flowering; never cut into bare wood
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Boston Ivy
Trim back from gutters, windows and the roof
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Hop Goodenia
Cut back by a third after flowering so it stays bushy
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NSW Christmas Bush
Cut stems for Christmas; that is its prune
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Bottlebrush, Weeping Bottlebrush and Bottlebrush Slim If you have time
Cut off spent flowers just behind the brush
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Thyme If you have time
Trim after flowering to keep it compact
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Grevillea If you have time
Tip-prune after the main flush to keep it dense
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Grevillea Moonlight If you have time
Light prune after the main flowering; remove spent heads
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Westringia If you have time
Trim after spring flowering; it takes clipping well
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Grevillea Strawberry Smoothie If you have time
Tip-prune after the main flush to keep it compact
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Star Jasmine If you have time
Trim after spring flowering
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Magnolia If you have time
Light shaping after flowering, if needed
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Feijoa If you have time
Light prune after flowering
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Running Postman If you have time
Trim runners after flowering
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Tea Tree If you have time
Trim after flowering; not into old wood
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Melaleuca If you have time
Trim after flowering
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Flannel Flower If you have time
Tip-prune after flowering to keep it bushy
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Native Frangipani If you have time
Light shaping after flowering
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Blueberry Ash If you have time
Trim lightly after flowering
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Grevillea Royal Mantle If you have time
Trim the runners after flowering
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Kalbarri Carpet If you have time
Trim the edges after flowering
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Dahlia, Marigold and Cosmos If you have time
Deadhead to keep flowers coming
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Rose If you have time
Cut spent blooms back to a leaf to keep flowers coming
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Echinacea If you have time
Deadhead, or leave late heads for the birds
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Foxglove If you have time
Cut the spent spire to the base
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Geranium If you have time
Snap off spent flower heads
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Basil If you have time
Pinch out flower spikes to keep leaves coming
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Butterfly Bush If you have time
Cut off spent flower spikes
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Brachyscome If you have time
Shear off spent flowers for more
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Yellow Buttons If you have time
Snip off spent flower heads
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Salvia If you have time
Cut spent spikes back to the next buds
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Day Lily If you have time
Snap off spent flowers
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Paper Daisy If you have time
Snip spent flowers for more
Watering
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Natives
Established plants: only in a heatwave or after 3 weeks without rain, then a deep soak
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Shrubs and perennials
Deep soak weekly in dry spells
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Azaleas, camellias and other acid-lovers
Shallow roots: deep soak weekly in dry spells
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Citrus
Deep soak weekly, more while fruit is setting
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Fruit
Deep soak weekly in dry spells, more as fruit swells
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Summer vegetables
Deep water 2-3 times a week; uneven watering splits fruit
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Herbs and annual flowers
Water when the top few cm are dry
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Red Flowering Gum and Red Flowering Gum (Dwarf)
Young trees: deep soak weekly in summer for the first two years
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Hydrangea
Thirsty: water deeply in heat, it wilts first
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Japanese Maple
Keep moist and shelter from hot wind: the leaves scorch
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Tree Fern
Water down the top of the trunk into the crown, daily in heat
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Daphne If you have time
Keep just moist: it hates both wet feet and drying out
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Smoke Bush If you have time
Water deeply in dry spells while young
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Kidney Weed If you have time
Water in dry spells or it browns off
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Blue Stars If you have time
Keep it moist in summer; it likes damp spots
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Sturt's Desert Pea If you have time
Water sparingly at the edges, never over the crown
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Rock Orchid If you have time
Water weekly in summer; keep almost dry in winter
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Christmas Bells If you have time
Keep it moist while it flowers
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Native Violet If you have time
Water in dry spells
Pests and diseases to watch for
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Every Brisbane garden If you have time
Humid weather: watch for leaf spot and mildew; thin crowded growth for air
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Bottlebrush, Weeping Bottlebrush, Bottlebrush Slim and Melaleuca If you have time
Sawfly larvae can strip leaves: snip off the clusters
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Tomato, Capsicum and Eggplant If you have time
Fruit fly: check fruit for stings and set traps
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Grevillea, Grevillea Moonlight and Grevillea Strawberry Smoothie If you have time
Check stems for scale; wipe off or use horticultural oil
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Pittosporum, Tea Tree and Bay Laurel If you have time
Scale and sooty mould: wipe scale off, or spray horticultural oil
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Cucumber and Zucchini If you have time
Powdery mildew: water the soil, not the leaves
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Apple Tree and Pear Tree If you have time
Codling moth: set traps, and pick and bin fruit with entry holes
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Rose If you have time
Black spot and aphids: bin spotted leaves; hose or squash aphids
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Box Hedge If you have time
Box blight: cut out brown patches, bin them and clear fallen leaves
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Viburnum If you have time
Thrips silver the leaves in summer; hose the undersides
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Crepe Myrtle If you have time
Powdery mildew: water the soil, not the leaves; prune for airflow
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Ornamental Cherry If you have time
Pear and cherry slug: hose off or dust with wood ash
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Wattle If you have time
Borers: if you see sawdust, cut the branch back below the hole
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Correa If you have time
Scale: wipe off or spray horticultural oil; keep air moving round it
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Clivia If you have time
Lily borer: check for chewed leaves and pick off caterpillars
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Waratah If you have time
Scale: wipe off or spray horticultural oil
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Lilly Pilly If you have time
Psyllids pimple new leaves: cut off affected growth
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Finger Lime If you have time
Citrus leafminer: cut off silvery curled new leaves
Frost and weather
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Plum Tree, Blueberry Bush, Raspberry Cane and Strawberry If you have time
Net against birds as the fruit ripens
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Magnolia If you have time
Mulch over the shallow roots to keep them cool; do not dig near it
Tidying up
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Tulip and Daffodil If you have time
Let leaves die down before cutting: they feed next year's bulb
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Dahlia If you have time
Stake stems as they grow
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Allium If you have time
Let leaves die down before cutting
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Iris If you have time
Cut spent flower stems to the base
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Watsonia If you have time
Cut spent flower spikes to the base
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Pink Everlasting If you have time
Pull out spent plants, or leave them to self-seed
Not listed: Cherry Tree, Blackcurrant Bush, Gooseberry Bush, Rhubarb, Blue Leschenaultia, Boronia and Common Heath, which don't suit Brisbane's climate.