In the garden: May 21, 2010

• I read in Monday’s paper that the average Brit spends six months of his or life discussing the weather. I wonder if that could be doubled for gardeners everywhere? Last weekend’s rain and fresh coating of snow on our mountain is a timely reminder that the chill of winter is just around the corner. Make the most of the milder autumn weather still lingering on.
• If your dahlia plants were too big, fell apart from the middle and flopped over this year, it is probably a sign that there are too many tubers. In cold climates, dahlias are lifted every year and over-wintered under cover. Here, where most of us just leave them to their own devices, often as roadside plantings, that lifting and thinning process does not happen. Be ruthless. As they die off for winter, lift and thin. You will get a much better display next summer and autumn.
• It is a good time to lift and divide day lilies (hemerocallis) which respond well to a bit of attention occasionally. If the clump is very congested, it is often the outer part which contains the greatest vigour and strength so discard the middle.
• Plant brassicas for spring eating and broad beans too. Continue sowing leafy greens to ensure regular harvests. Most of the quick maturing Asian greens can be grown over winter as well as silver beet and winter spinach. Peas can also be planted.
• Get an autumn copper spray onto citrus trees to prevent leaf drop, fruit rotting on the tree and a range of nasties. This is a critical spray to carry out if you want to protect your harvest. Mandarins are particularly vulnerable.
• Don’t let the autumn leaves build up in your fish ponds. Rotting leaves can reduce the oxygen levels in the water and even kill the fish in extreme cases.
• Keep a sharp eye on weeds. With the shortening day length, pesky cress does not bother about growing large. It just goes straight to seed, as do other weeds.
• Green crops must be sown now if they are to make some sort of growth before winter and to justify their role in nourishing the vegetable garden. Don’t put it off. Green crops develop a root system which makes the soil much easier to break up and till in the spring, particularly with heavier soils.