Despite trying all the usual rose sprays, nothing seems to stop rust - can you suggest something?
- Chrissy Barrett

Rust is a fungal infection which is easily spread around your garden and is exacerbated by humid, still weather. It is best treated during winter. If you leave it this late in the year things can really get away on you. Here are some things you can try now, as well as a programme to follow next season. Number one, be a tidy Kiwi. Keep old plant material away from your plants. Remove any signs of the infection from the plants. This means in winter giving your roses a good old hiding with loppers. Make sure you burn all infected material. Shape your roses to encourage good airflow and water at the base only, not on the foliage. Feed your plants with Kings rose food this spring and potash next autumn. Try spraying prophylacticly with 1 teaspoon baking soda, three cloves crushed garlic and 1 tablespoon olive oil per litre of water once a fortnight in spring.

Our peach tree is suffering from leaf curl. Are there any cures that don't involve spraying toxic chemicals?
- Isobel

There are two types of leaf curl - fungal and viral. Both need to be managed rather than being treated. Firstly, it's important to be proactive when dealing with these infections. You need to spray the tree just as the weather warms before the infections start to take hold of new growth. For the fungal infection you could try a baking soda and oil spray or you could try a copper-based spray. For the viral side of things you need to keep the white fly off the tree. I recommend regular treatments of garlic spray. To do this, soak a garlic bulb in a litre of water for 48 hours then mix with half a teaspoon of garden-friendly soap and a tablespoon of oil. Next year grow some Kings beneficial insect blend under your tree to attract white fly predators.

My 5-year-old Mexican blood flower climber grows vigorously on a north-facing deck railing but fails to produce more than one single flower each year. It should have hundreds! Any idea why? I have typical Waitakere clay soil.
- Jade

This a tropical native and sounds like a beautiful specimen except for the lack of flowers which can come down to a few things. Firstly, soil conditions can have a bearing. Make sure you improve that clay soil with a good friable compost and mulch. Over-watering is another reason your blood flower won't do the business. It comes from the same area as the bougainvillea and likes a light moist soil. Lastly, temperature may also be an issue. Any cold snap at the wrong time may stress the plant. You could invest in some frost cloth for winter and try and keep those delicate buds protected. In a tropical climate it will flower all year.

Weekend checklist

* Water tomatoes regularly, but remember not to water the foliage.

* Make sure your tomatoes are staked properly before they get too big, when they can be damaged easily.

* Mulch around your plants now before the dry, weather starts. If your garden is already dry, wet the mulch.

* Keep your garden tidy - dead head flowers and remove spent foliage, as this can harbour fungus spores.

* Plant cropping vegetables now. If you haven't germinated any seeds visit Kings and get your hands on some punnets.

* Slow down on watering your garlic but keep watering your onions.

* Get your kumara shoots in the ground - dig a pit about 100mm down, line with wood ash or charcoal (untreated only), form the shoot into a J shape then plant and water. Grow the vines up tepees to ensure the biggest tubers.

* Spray the garden with a mix of 1/2 a teaspoon of garden-friendly soap, three cloves crushed garlic, 1 tablespoon of oil and 1 teaspoon of baking soda for every litre of water.

* Treat yellowing foliage with Epsom salts (follow the instructions on the packet closely).

* Chop up prunings and hedge clippings finely, this will give your compost a good head start when it comes to digesting the huge amount of waste your garden can produce.

* Mix your lawn clippings into your compost thoroughly when, you guessed it, it's time to turn it over.

* To ask Justin a question, click on the email link below.