Landscape gardener and Life columnist Justin answers your questions.
We have a bank about 2m high and 27m long at Mangawhai Heads. It is 100 per cent sand (0 soil content) and covered with kikuyu grass at the moment. I would like to plant something nice looking that will grow in sand and hold the bank together. Any suggestions? (Please don't say agapanthus!)
- Mandy Miller
Beauty is of course is in the eye of the beholder but the first cab off the rank for me is muehlenbeckia axillaris - a coastal ground cover that has a spreading, disorderly habit with small green leaves and a pretty but insignificant yellow flower. Another ground cover is metrosideros carminea, the rata vine. Once established, this has a compact habit with a bright show of pohutukawa-like blooms in spring. Astelia nervosa provides a strong accent to most plants as does xeronema callistemon with its radical red proboscis, while strelitzia, or bird of paradise, imparts both drama and colour. Chamaerops humilis is a compressed, dynamic and very hardy branching palm and don't forget the aloe and agave family. I find their chunky nature can put some people off but if you soften this with flowers, (try eschscholtzia californica and calendula) they won't look overly macho. Besides, aloes have a pretty flower of their own.
I'm planting a fernery in the shade corner of my section, using ferns and pongas "rescued" from pine forests about to be felled. Do you have any tips for successful transplanting? I am having mixed results. People say you're supposed to cut all the fronds off and let them regrow - is this a good idea?
- V. Suckling
Try to mimic the situation you have rescued your pongas from in the first place (without growing a pine forest). Take as big a root ball as possible and mulch, initially with dry pine needles. Plant in a good friable soil and water heaps. Make sure they are in full shade. Cutting the fronds off is important as it encourages root growth. Make sure you cut them as far down as possible as any remaining frond stumps can close over the new fronds as they emerge.
My teucrium fruiticans hedge is being eaten by snails (I think) - it's looking woody like lavender. Any suggestions on how to get this under control and back to a full hedge? I've been scattering snail pellets but I'm not sure if it's working. It also has regular trims.
- Maggie
Teucrium fruiticans is a semi-arid plant, native to North Africa, and has a very woody look to it once trimmed. I haven't heard of slugs being a particular problem. It doesn't like wet feet, and new shoots may be susceptible to moth caterpillar damage, similar to that seen in a kowhai tree. Look closely at the new shoots for tiny holes into the stem. The caterpillars can often strip the plant from the inside out. You can spray with a mixture of garden friendly soap and olive oil diluted in water, or try Yates Success from Kings. To make sure it's not slugs, clean away anything that could form a slug habitat like leaves or mulch from under you plants, then go outside at night with a torch. Look carefully - if slugs are the problem they'll be small but you'll be able to nab the blighters in the act.
After trying many other people, we thought we'd ask you about our No Fruit Grape Gripe! Some 15 years ago we planted Albany Beauty bought as excess stock from the local orchard. It turned out to be a green grape (although A B is apparently Black) so no guarantee of variety for a start. The vine has grown well, covering a big open crucifix-type affair (10 meters across) in our breezy, sunny, well-drained orchard of mainly Braeburn apples. It took about eight years for us to get any grapes but at last fruit did appear. The bunches looked quite promising to start with but as the fruit got larger (from maybe January onward) most grapes started to dry up, with some forming large black spots. So last year we made it our mission in life to "save the grapes". We had our arborist friend give a professional prune. We sprayed copper oxide (powder made to manufacturer's instructions) at fruit set, when the tiny green beads appeared, then again toward the summer. We looked at the vine, we talked to the vine, we threatened it with annihilation, but still only a few black speckled green grapes made it to maturity - the birds didn't even bother with them. So what do you think? Shall we call it time and start again?
- Sandra and Martyn Hooper
Your grape is of dubious pedigree and, sorry to say, this can have a huge bearing on things. I recommend growing a variety right next to it you know will do well in your area. The problems you describe could be any number of things but if I had to pick one I'd go for phomopsis, cane and leaf spot. This is a fungal infection that's held on the wood and foliage so spraying after fruit set is a little late to be effective. Although phomopsis is inactive in the foliage during the warmer months it attacks the fruit as the sugars mature.Try spraying Yates Champ DP or Copper Oxychloride from Kings. I spray mine with a mixture of seaweed and baking soda. Over the summer spray once every three or four weeks. Also spray when the new shoots first appear in spring and then again when the temperature cools down. Over winter spray with sulphur.
Weekend checklist
* Seeds to plant include beetroot, broccoli, cabbage, capsicum, carrots, cucumber, lettuce, kumara, onions, parsnip, peas, radish, rhubarb, shallots, silverbeet, spinach, sweet corn, tomatoes and zucchini, potatoes, aubergine, summer flowers, basil, coriander, french tarragon (in pots).
* Plant more of the things that are coming on now like lettuce, parsnip and beetroot. This way you can stagger your harvest.
* Slug control - use beer traps, Quash, or pay your kids per slug. Better to send them out at night with torches.
* Mulch all beds with straw or compost. Put newspaper under your mulch to suppress weeds.
* Plant dahlias and gladioli.
* Start your prophylactic spray programme. I use organic sprays I make with stuff out of the kitchen like garlic, baking soda, olive oil, and garden-friendly soap as well as seaweed from the beach, but for a full range of chemical and organic sprays go to Kings. Common ones include oils, fungicides, insecticides and herbicides - always read the label carefully, wear protective clothing and wash yourself thoroughly after use.
* Organise comfortable seating areas around your garden. To find the best spots, follow your cat.
* Prepare your beds for tomatoes. If you are planting them out now, stake them straight away with a stake that is big enough to hold the tomato of your wildest dreams.
* Spring clean all of your garden beds, feed your lawn, trim hedges, add compost and mulch around fruit trees.
* As always, turn your compost.
* To ask Justin a question, click on the email link below.
