Landscape gardener and Life columnist Justin answers your questions.

In a previous issue you mentioned a tip for preventing blight in tomatoes. Can you advise what that was? Also, is there a spray to treat canker on old apple trees? If so, when is best to apply?

- Thanks, Mark

(Plus Robyn asked for a recipe for my fruit tree spray, containing garlic, water and while Joan and Diane wanted my baking soda and garlic spray for roses. )

The method for blight prevention is three-pronged. Firstly, make sure you don't plant anything from the nightshade or Solanum family in the same place in any three-year period. Secondly, keep the soil as free from un-composted carbon material as possible, as this promotes fungal growth. Finally line the hole with milk powder and Epsom salts before you plant your tomatoes. Follow this up with a spray programme using milk spray, approximately 40 per cent milk and 60 per cent water.

Canker is a fungal infection infecting second-year wood. The tree will often fruit well because the infection puts the tree under stress, so that as the sap rises in spring the tree will over-compensate for its poor condition. Unfortunately canker reduces the quality of the fruit and can affect its storage qualities. The first thing is to remove, and burn or dump the infected material. Protect the wound by either bleaching it with a 10 per cent bleach-90 per cent water mixture, or by wiping soil over it. Make sure the cuts slope down so any water will run off. Secondly, apply lime to the soil. This encourages hard new growth which is more likely to remain healthy. As soon as fruiting has finished, prune the tree out ready for the next season's growth and remove all of the litter during leaf fall in autumn.

My aphid spray is made up of one teaspoon of each of neem oil or olive or vegetable oil and a garden-friendly dish soap ( I use Eco brand) mixed in one litre of water. My garlic rose spray is simply made by soaking three or four cloves of garlic in one cup of water for 48 hours, then mix it all together and apply with a garden sprayer.


For mealy bugs mix 10mm of pyrethrum and 1 teaspoon of dish soap in one litre of water, while one tablespoon of baking soda per litre of water takes care of mildew.

I want to locate the tiny cherry tomatoes called red currant or similar. I believe the common cherry started from these and they're smaller than typical cherry ones at about a 1cm radius. I have Googled but no one seems to stock them.

- Alison Brown

The red currant cherry tomato is an heirloom variety so you might want to try the Koanga Institute, who, even if they don't stock the seeds commercially, may have a contact who has saved them for their own use. Have a look at Kings Seeds who have an amazing variety of cherry tomatoes. Even though you may not get the exact one you want, you may find a substitute which is satisfactory for this season at least. My last port of call is Trade Me. There are a few seed collectors there who may have just what you're looking for.

In the vege garden
* Direct sow root crops such as carrots and beetroot.

* Everything else can be either direct sown or started off in trays. If you can't be bothered growing from seed, buy punnets and get planting.

* Keep the young seedlings well watered and cover with shade cloth for a couple of weeks after they emerge.

* Be wary of late frost in inland areas. Keep an eye on young vulnerable seedlings such as peppers and tomatoes which may require frost protection.

* Plant French tarragon ( my favourite herb) in a big pot instead of in the ground where it will rot when it is dormant over winter. Feed with liquid fertiliser and mulch with pea straw. Re-pot and replace the soil every two years.

* Strike kumara shoots and prepare the beds. Simply bury a kumara in the garden or in a pot of pumice, and when the shoots reach about 20cm, plant out. To prepare the beds and add some potash to the soil. To save room, train the vines up a tall stake. This also encourages the vine to grow larger tubers rather than lots of little ones.

* Combat slugs and snails by ringfencing vulnerable crops with bird netting. Make sure this is bunched up so even the most determined invertebrate will get tangled.

* So they will be ready to harvest in autumn, plant celery and parsnip now.

* Watch out for aphids on new spring growth. Make sure your plants are watered regularly and spray if necessary. To make your own spray, see my recipe in the questions to the left.

Flower garden
* Remove leaf litter from the garden to avoid fungal infections.

* Apply calcium to new beds. New Zealand soils are generally deficient in calcium which acts as a holding agent in the soil for more important trace elements. Calcium also improves the viscosity of heavy soils.

* Move self-sown seedlings like poppies or marigolds around your garden. Don't forget to plant some sun flowers. These are a real winner for adding a bit of impact, colour and structure.

* Plant out summer favourites. I'm going orange with marigolds, California poppies and celosia.

Lawn care
* Get started on lawn regeneration. Begin by applying gypsum to get rid of moss and rake out thatch using a plastic leaf rake. Rake in fresh seed mixed with sand and good quality soil, and keep well. Feed with low nitrogen fertiliser of your own urine watered five parts water, one part wee. It's totally safe, I promise.

Trees shrubs and hedges
* Feed citrus now especially if they're looking a bit worn out with yellow leaves and poor flower bloom. Use plenty of rich organic material and dilute a cup of Epsom salts (Magnesium sulphate) in a bucket of water.

* Trim and feed young hedges but wait a month or two to trim the more established ones. Be careful not to take too much off, as this can lead to holes which won't repair themselves until next year.

* Feed your hedge using organic material such as sheep pellets or wool dags if you can get them.

* Mulch landscape gardens to keep the ground moist. Tree mulch on top of cardboard also makes an excellent garden path.

* Plant big trees on the south or western side of your property so you don't shade the sunniest parts of your garden.

* If you are planting for privacy on your northern boundary, use deciduous trees so in winter when the light is at its most precious the trees will be casting minimal shade.

Do you have a gardening, DIY or landscaping question for Justin? Email with your question and we will be happy to answer it in our pages.