Gardening: Fixing foliage

Landscape gardener and Life columnist Justin answers your questions.

Further to the earlier question about the puka tree. I have one that is higher than my single-storey townhouse, blocking a lot of sun. I want to cut it completely but was going to wait for January 2012, when cutting of trees will be legal. I want to do the right thing as I understand the puka is a native.
- Susan

If you are worried at all about the legal ramifications of cutting down a tree, contact your local council or phone a qualified arborist to take a look. Your local council website should provide you with some specific guidelines. Councils often allow a small amount of a protected tree to be judiciously pruned, so contact them to find out. It's better to be safe than sorry.

My 3-year-old olive trees are looking very spindly - they've been in Kingsland clay soil and we've trimmed them to make them thicken and form a hedge but they are not looking good. It is the manzanilla variety, I think. What can we do?
- Jacinta

The manzanilla is a Spanish olive. I lived in Kingsland once and can't recall it being much like Spain. The best olive for your area is the imaginatively named J5, which is produced from cuttings of a tree that was planted near Hokianga around 1830. I recommend mulching heavily with straw and compost to try and build up the soil. Remove the limbs from any competing trees as olives like full sun. But unless conditions are absolutely perfect, particularly in the sun department, I think you may be being overly ambitious. Ole.

How can I get rid of creeping oxalis and kikuyu in the lawn? I would like to be able to do this with without losing all the grass, and have the area ready for a touch-up sowing in the spring.
- Maureen

Kikuyu thrives in sandy, dry conditions, so the first thing is to keep your lawn well-watered. Winter is the wettest time of the year, so that will help. Kikuyu has a spreading habit, so when you see the grasses appear try to pull the whole tendril out. This will leave a valley in the grass which you can fill with some lawn mix and grass seed. Keep doing this as the weather warms up to get on top of it and re-establish some finer grasses at the same time.

The pre spring task list

In the vege garden:
Plant garlic, onions, spring onions, lettuce, parsnip, beetroot, carrot, peas, celery, cabbage, coriander and in a warm spot or a cold frame, sow chilli and eggplants.

Finish planting deciduous fruit trees. Staking is important as spring is usually very windy.

Plant herbs and divide rhubarb.

In the flower garden:
Plant hydrangeas now. They are not flowering but they will be soon, especially if this mild weather continues. They make excellent borders and suit most gardening styles.

Split up red hot pokers once they have finished flowering. The miniatures flower a bit later on so let those come to flower first.

All your roses should be put to bed now- defoliated. To protect against future black spot make sure they are mulched and give them a spray with baking soda and olive oil mixed with soapy water. Tidy up any midden around the bottom of plants.

Begin planting spring flowers, although we may have some cold weather ahead and they may still need some protection.

Compost doctor:
Check to see if your compost is too wet or dry. If it's wet add a good amount of brown matter and dry soil. If it is dry, pull the heap apart and reconstruct it watering each 150mm layer well.