December growing guide
🔆 High 25° | 🌙 Low 18° | 🌧️ 7 rainy days
Life really starts ramping up at this time of year, and things are certainly starting to bear fruit in your patch. It’s December! Let the festivities and gardening begin!.
Veggies
For some super temperate herbs, try basil (both sweet and purple), parsley, thyme, rosemary and lemongrass. Coriander doesn’t like the heat so will go to seed easily. Plant seeds every couple of weeks or so to maintain a steady supply. Mint can also be planted now but you might want to keep it in a nice sized pot… it’s a grower, and a leafy invasion is just not mint to be!
I love yellow squash roasted whole in the oven or chargrilled on the BBQ and now is the perfect time to get some in the ground. They love an open, sunny spot with really good drainage. Dig in plenty of organic matter and throw in a handful of potash to encourage loads of flowers, and therefore fruit.
Drape shade cloth over salad green if it gets really hot – it'll stop them wilting and turning bitter. Improve pollination of sweet corn by shaking pollen from the tassels at the top of the plant. They’re wind pollinated so get the kids to imagine they’re a storm.
Mulch tomatoes with old compost or manure. Remove bottom leaves to reduce disease problems. Sow basil at the same time as tomatoes. As well as pairing deliciously together, basil is said to keep pests away from the tomatoes.
Top up the mulch in your veggie patches and herb gardens, especially important if you are heading off during the holidays. A hot summer tip is to mulch after watering the patch, to a depth of about 7cm. Keep mulch clear of plant stems, especially young seedlings. Choose sustainable varieties such as sugarcane, pea straw or lucerne that will enrich your soil as it breaks down and keeps our worms cool. Wood chip mulches are too heavy for the patch, so leave those for your trees.
What to plant in the veggie patch
It is already pretty warm, so if you are heading away for a while it’s probably best to avoid planting at this stage. If you are hanging around, why not try some of these favourites: silverbeet, lettuce, leek, beans, corn, squash (summer), leek, eggplants, beetroot, carrots, chilli, cucumber, eggplants, pumpkin and zucchini.
Fruit
Keep. Them. Watered. You can’t get juicy fruit if your tree isn’t drinking! Fruit trees need water to size up their fruit properly. It's best to water deeply and infrequently rather than shallowly and often. Water trees on sandy soils every 1 to 2 weeks providing enough water so it sinks at least 60cm into the soil. On clay soils, water every 2 to 3 weeks. The frequency will vary depending on weather conditions. For young trees, make a moat around the base of the tree so the water stays in the root zone. On older trees, water at the drip line ,which is the line of the furthest leaves.
Feed mangoes with a complete fertiliser to encourage production of healthy fruit and spray with Copper Chelate to protect from fungal diseases.
Harvest strawberries regularly and make sure they’re protected from snails and slugs with coffee or yeast traps.
And remember that your trees need mulching as well. It’s safe to use a heavier bark-based mulch on established trees, which has the added advantage of being a great habitat and food source for lizards.
Natives
Cut back spent flower stems of kangaroo paws ensuring that the old leaves associated with it are also removed at the same time. This old foliage is usually starting to blacken by this time anyway and its removal will hasten the development of lateral buds from the base of the shoot. These buds will grow out to produce the next flush of flowers the following season.
Lilly pillies will benefit from a light trim with hedge shears this month. A handful of slow-release native plant fertiliser watered in around the base of the plant will stimulate the next flush of vegetative growth, which is particularly useful if you are trying to establish a lilly pilly hedge. If your variety of lilly pilly is prone to psyllid damage (which cause leaf pimpling), pruning will also help to remove damaged foliage.
Trimming NSW Christmas bush for cut flowers this month will also serve to prune the plant and initiate the growth which will mature into next year’s flower display. A generous layer of well-rotted chook manure spread around the base of the plant will ensure some good long stems that are ideal for cut flower use.
Feed bottlebrush with a handful of general purpose complete fertiliser to encourage an autumn flush of new growth that usually terminates in a nice burst of flowers before the winter. Bottlebrushes do best when planted in soils that receive plenty of moisture and in such situations, they will often repeat flower through the warmer months.
If you have not already done so prune off the spent flowers on bottlebrushes (Callistemon species) to just behind the old flower heads. This will prevent the seed capsules from forming and give you a good compact shrub.
Flowers
Why not try some lovely flowering plants as well? Nasturtium, verbena, petunias, marigolds, phlox and celosia are great at attracting pollinators and beneficial insects to your patch. They add a touch of pretty to your patch too.
To avoid a dead scrappy look at Christmas, cut dead blooms off agapanthus, roses, hydrangeas, daylilies etc. to encourage them to keep blooming.
Soil and mulch
Consider a green manure crop to add some life and love to an overworked patch. At this time of year, try cow pea, mung bean, soybean and millet. This will improve your soil incredibly and return some nutrients needed for healthy, vigorous growth. With a bit of forward planning you’ll find it well worth the effort!
Dry soil can repel moisture. If your soil is still dry just under the surface after you've watered, use a wetting agent so that the next lot of water can really penetrate down to the roots.
And… Have I mentioned mulching? Mulch, mulch and mulch will help protect your plants from the worst of the heat.
Pest watch
Scale insects breed at this time of year. Inspect plants carefully, especially susceptible varieties such as gardenias, lillypillies and citrus. Spray with a homemade white oil solution. Add about 100ml of vegetable oil to a splash of dishwashing detergent in a container. Shake mixture until it turns white and soapy. Add about 20mls to about 1 litre of water and spray onto scale insects. This will suffocate them, and they will eventually fall off.
Trap earwigs by filling plant pots with crumpled newspaper and laying them on their sides in garden beds. Check each morning and destroy pests.
Two spotted mite (also known as red spider) can be kept in check by regularly mist-watering over leaves. An organic horticultural spray can also help with their control on roses and ornamentals.
Remember to water in the morning to reduce risk of fungal disease.
Everything else
Plants feel the need for a feed at this time of year. A seaweed tea or low environmental impact liquid fertiliser is perfect, especially for seedlings planted in November, which’ll be ready for a bit of a feed by now. Apply to the soil early in the morning, and in the concentrations mentioned on the packet.
On non-gardening days, why not head out to the shed and construct a couple of shade cloth tents. They don’t have to elaborate – just a simple, moveable structure that you can pop over the top of some of the sun-sensitive veggies (like eggplant, capsicum and others) as the heat becomes more intense. Think of it as slip, slop, slap for plants! Pop these around where required, especially on high UV days, windy days, and during your holidays.
Remember pets need cool water at Christmas too! Make sure their water bowls aren't in the sun and change the water often. A rock in large containers helps to stop them being knocked over.
Protect your pot plants while you are away this summer. A small volume of low environmental impact water crystals applied to each pot will help keep the plants watered. Mulch the top of the pots, sit them in a saucer of water (or the bathtub if it gets enough light inside) and you’ll be set!
Give the gift that keeps on giving. A productive pot plant! There are potted plants to suit every back pocket, and some awesome selections include chilli, cherry tomatoes, citrus, olives or a mixed herb pot. Get creative!