In the Garden: April 30, 2010

• I am reliably informed that the autumn colour in colder inland areas is at its very best. The sudden cooling of temperatures in March followed by a long, dry and calm autumn has resulted in a splendid display. If you are wondering why we never get great autumn colour in coastal areas, it is because we lack the sharp seasonal changes which trigger deciduous trees to colour before dropping.
• Cleaning up fallen leaves and spoiled fruit from under your fruiting trees helps to reduce pests and diseases which can winter over in the debris. This is particularly true with apples and pears. Lay a blanket of compost after the clean-up to suppress weeds and to condition the soils.
• If you are wondering how to prune your raspberry bushes, we will do an Outdoor Classroom on this shortly. While timing is not critical, it is easier to see what you are doing when the leaves have dropped. The rule of thumb is that you remove all fruiting canes from this summer and just keep the new canes.
• Finish the autumn feeding round as soon as possible. While evergreen plants don’t go dormant like deciduous plants, their growth slows right down over winter which slows their ability to take up fertiliser. There is no point in feeding deciduous plants which are dormant or in the process of going dormant.
• Despite being horrified at the price and initially suspicious of an approved organic spray for aphids, Mark was pleasantly surprised to find that Yates’ Nature’s Way did actually work on the swan plants – killed the aphids without affecting the monarch caterpillars at all though it needed repeat applications because it is nowhere near as powerful as the pyrethrum based sprays. On the other hand, the Tui product, Eco-Pest, which is primarily canola oil, had absolutely no effect at all on the aphids when applied at the recommended dosage.
• Most gardeners will be looking at some pretty sad and leafless tomato plants by now. Unblemished tomatoes can be ripened off the vine so harvest these now and keep in an airy, light place to ripen. Gather up all the spent tomato plants and leaves and dispose of them in the rubbish or by hot composting to reduce fungi spores wintering over. I see the advice from Andrew Steens in the Weekend Gardener magazine is to put such diseased foliage on your lawn and then run over it repeatedly with a mulcher mower to chomp it up and leave it to feed the worms in your lawn. This of course assumes that you not one of those ecologically challenged types who kills out the worms in your lawn to preserve a better green sward.
• Some time ago, I wrote a glowing review of The Artful Gardener by Rose Thodey and Gil Hanly. I see it has been reduced from $60 to $25 on special at Touchwood Books (www.touchwoodbooks.co.nz). It was worth its original price, let alone the reduced price.