• If you see white butterflies hanging around your vegetable patch, odds on they are laying eggs on your baby brassica plants. Early intervention means you can usually rely on digital control (don’t be squeamish – squash the caterpillars) but if you let them get away on you they will either ruin your crop or you may have to resort to chemical control. Covering the plants with fine netting can keep the white butterflies away but you really need to build a temporary frame to hold the netting away from the plants and to get rid of any eggs and caterpillars already present. There is nothing more likely to discourage children from eating broccoli than coming across boiled green caterpillars in it (the voice of experience here) so it is worth trying to keep the plants clean. You can still be planting brassicas and other leafy greens for winter harvest.
• Celery and leeks are two vegetables which are better with pale stems (the greener they are, the tougher they get) so if you have them in the garden you can earth up around the stems to blanch them.
• If you are digging carrots with holes in them, the culprit may be weevil or carrot fly. Sometimes slugs will also have a go at getting in on the act. It is too late to solve the problem now and we just cut the bad bits out. You can’t do anything about weevils and dealing to carrot fly is hit and miss where recommended treatments tend to be heavy duty insecticides like Diazinon. Late plantings tend to escape carrot fly and look for varieties which are marked as resistant. Well cultivated soil discourages weevils in the longer term.
• Readers who have nice tidy hedges bordering garden beds may pale at the prospect, but rootpruning close to the hedge is advisable. This is just making a deep cut with a sharp spade to stop the hedge roots making inroads to the garden beds. It is even more important if you have a cutsie potager with small beds, because all that hedging robs the goodness from the soil. Really organised or experienced gardeners know to lay a barrier of non rusting iron or similar just below soil level when they first plant the hedge, so containing the roots. But most of rely on the occasional root prune.
• While the dry weather continues and there is some heat in the sun, get out with the push hoe for weeding and to till the top layer of soil. If you rely on spraying weeds with glyphosate long term, you end up with soil which becomes compacted and often develops a top skin of moss or liverwort. Breaking this up with a push hoe aerates the soil as well as giving a more cared-for appearance. Once the autumn and winter really set in, the push hoe is not as useful because you also have to rake up the debris (the sun isn’t hot enough then to dry it for you). Mark, who is on crutches this week and therefore developed cabin fever by the second day, is pondering whether he can attach the push hoe to a crutch and remain active that way.
• Random information from the Curious Gardener’s Almanac: the honeybee kills more people around the world each year than all the poisonous snakes combined, but the creature responsible for the most human deaths worldwide is the mosquito, by a considerable margin.

• We are getting back into the ornamental garden here, after the summer hiatus. No planting of woody trees and shrubs yet (wait for the second lot of good rain in succession) but replanting bulbs, lifting and dividing grasses, trimming the formal hedges and repotting some of the container plants. We are even starting the major autumn clean-up round.
• Continue preparing ground for new lawns by levelling the area and push hoeing off the waves of germinating weeds that will attempt to colonise the bare earth. Don’t be tempted to sow grass seed until we get some consistent rain that penetrates more than a centimetre or two.
• Avoid feeding existing lawns in dry weather because fertiliser will kill the grass in sunny, dry conditions. Watch the weather forecast and wait until it is certain that we are in for a wet spell before heading out with the fertiliser. As always, remember that more is not better. If you are using a proprietary product, follow the instructions and err on the mean side, not the generous one. An overdose of fertiliser can cause all sorts of problems, including burning and death.
• Delay no longer on getting the winter vegetable garden in because you are running out of time and good intentions will not fortify you against high winter fresh veg prices or the somewhat dreary alternative of frozen vegetables from the supermarket. You can still get in plants or seeds of cabbages, cauli, broccoli, peas, winter spinach, silver beet, Florence fennel and winter lettuce. Most of the root crops (carrots, parsnips, swedes etc) take longer to mature and you will only get baby specimens if you put them in this late.
• Leafy green vegetables tend to be gross feeders so if you didn’t add plenty of compost, fertiliser or manure to the garden before you planted them, feed them now to encourage plenty of growth.
• If you are using manure, sheep, cattle and horse manure can be added directly to the soil but be a great deal more cautious with chicken manure (or mushroom compost for that matter). If you want to err on the safe side, put them through the compost heap to dilute them before you use them. Chicken manure is very high in ammonia and can burn plants in its fresh state. Seaweed is another natural resource which can be used directly onto the soil or composted as you wish. It does not need to be washed in fresh water first.
• Should you have a patch of common nasturtiums, if you can be bothered gathering the seed pods, when pickled they are almost indistinguishable from expensive capers. If you are desperate to be self sufficient, you can apparently dry the seeds and grind them up as a pepper substitute.
• The quote of the week is sure to appeal to middle aged gardeners and comes from Samuel Butler: “Youth is like spring, an over-praised season more remarkable for biting winds than genial breezes. Autumn is the mellower season, and what we lose in flowers, we more than gain in fruits.”
A reassuring thought to one who had an unwelcome birthday last week!

• This week’s cold snap is a reminder that summer really has gone for this season and you mustn’t delay on getting the winter vegetables into the ground. You have missed the boat on brussels and main crop carrots, parsnips and leeks but you can still plant all the brassica family, Florence fennel, spinach, peas and winter salad vegies.
• Make sure you get around to collecting your harvest of onions, pumpkins and anything else that is ready. It doesn’t do them any good left lying in the open, especially with the rains.
• If you have spare ground in the vegetable garden, sow down a green crop for winter – lupins, oats or rye. Continually cropping the same ground strips out the goodness from the soil and digging in a green crop later is a much better approach to replenishing the fertility and improving the soil texture than relying on artificial fertilisers.
• Sow annuals for winter and early spring flowering into trays now, if you want an early start. It is much cheaper to buy seed than plants. Annuals such as pansies, poppies and cornflowers are easy to grow from seed but you need to get them started in trays and then transplant them into the garden when they have a bit of size and a good root system.
• It is very close to your last chance to prune cherry trees and plum trees this season. Don’t leave it any longer because winter pruning makes them vulnerable to disease, particularly silver blight.
• It is a good time for taking cuttings of easy to root plants such as fuchsias, vireya rhododendrons, many perennials (ones like pinks and carnations which don’t clump) and even hydrangeas. All these can be rooted without special facilities. Select new growth which is firm and doesn’t snap when flexed, make a clean cut at the base, take a sliver off the bottom 2cm of the cutting (two slivers either side for a vireya) and put into potting mix, preferably one without fertiliser added. Not all plants are easy to root. In fact some are extremely difficult and without a home propagation unit (a hotbed) you are unlikely to succeed with most trees, rhododendrons, camellias and the like. Sadly, most fruit trees are budded or grafted and those that are done from cutting are not likely to root easily for the home gardener.
• Readers who recall the story last year on the local importers of Italian heirloom vegetable seed may be interested to know that their website is now up and running at http://www.italianseedspronto.co.nz. It is the wrong season for all those delectable tomatoes, basil, aubergines and the like (these are crops to sow in spring) but they do have some interesting brassicas, radicchio and finocchio (the latter being fennel bulbs).

The quote for the week comes from the late, great American architect, Frank Lloyd Wright:

A doctor can bury his mistakes but an architect can only advise his client to plant vines.

·         If you have outdoor grapevines which you have not yet covered, get the bird netting on as a top priority if you want any crop at all. The birds will eat them at an earlier stage than you and will completely strip the crop or open up the fruit for wasp attack.

·         A reminder to prune the fruited canes off your raspberries, if you have not yet done so (and we haven’t). If they have borne fruit this year, they are now redundant and merely clutter the place up because next summer’s fruit will be set on this season’s fresh growth.

·         Do a feeding round now on fruit trees, both deciduous and citrus. Feeding deciduous trees such as apples and plums now gives them time to take up the sustenance before they go dormant. If you are avoiding ready mix fertilisers, rich compost can be used but don’t build the layer up around the trunk.

·         March heralds the start of autumn. While we can expect a very long and mild autumn in our climate, getting the winter vegetables in should be a priority so they can do all their growing done and then most will just sit and hold in the ground when the cold weather comes. Winter vegetables take in the brassicas, winter spinach, peas and root crops such as carrots, swedes and parsnips. Sow the root crops first because they need longer to grow and it is getting late for them. It is the late winter and early spring vegetables which are the most expensive to buy so successional sowings now will save money later.

·         Gardeners in colder, inland areas should be starting to think about a pruning round on hedges because the plants are happier if they can make a small amount of fresh growth before colder temperatures stop them from growing until spring. The trick is to get the timing right so that growth is just a neat fresh flush and not a full on growth which will look untidy in winter.

·         A buxus expert we spoke to this week tells us that buxus blight (which turns the plants brown in big, spreading patches) is made a great deal worse by feeding and watering. Plants which are grown in drier, harder conditions will stay healthier. She also thins her plants to keep air movement. If you want to try and hold buxus blight at bay, don’t let your plants get too dense. She confirmed the advice we gave readers earlier: if you have a bad infestation, burn the plants and replace them with something different. Long term, there is little chance of beating buxus blight so the sooner you bite the bullet, the sooner you get other plants established.

·         Henry Mitchell, the deceased garden columnist for the Washington Post, wrote as recently as 1998: “There is a dangerous doctrine – dangerous because it precludes endless gardening pleasures – that every plant in the garden should be disease-free, bug-free, hardy to cold, resistant to heat and drought, cheap to buy and available at any garden centre.” Nothing has changed in the past decade, except that the plant is now expected to be low maintenance as well as all of the above.