The Permacultivator - Journal of Cool Climate Permaculture
A guide to marriage and a berry productive harvest by Sharon Lamont
Raspberries prefer the cooler areas such as the higher regions of NSW, Tasmania and Victoria, so are suitable for the Southern Highlands which has an altitude of 600-700 metres ASL. They generally produce for up to fifteen years. Of course they like the best conditions: a good friable soil with loads of humus, compost and manure. They must be provided with some protection against strong winds which can break the fruit bearing laterals. They also need protection from hot afternoon sun and relief from poor drainage. You could try underground plastic piping at a depth of 40-50cm to drain excess water.
Erect a trellis prior to planting. Think of it as a deciduous future fence. The type of trellis depends on the length of the row. For four people a few bushes will suffice therefore a post at either end of the row with three evenly-spaced strands of wire (the first starting at 100cm above the ground) will provide enough support.
Think about raspberries at the end of summer so that you have time to prepare the soil. Choose a good site and erect your trellis. Planting time is late autumn or winter. Plant one metre apart and 20cms deep. Try to plant three canes per hole so that a mature bush can be established quicker. You may not get fruit the first year but this will help create stronger canes producing more fruit in the second season. If manuring, be careful not to place on new canes to avoid burning them. In late summer, even when picking is finished, water deeply once a week to keep canes strong and healthy.
Every Winter cut out the old canes with long handled secateurs as low to the ground as possible and tie up new canes onto the wire. Theoretically, if you leave old canes on, they take up the room for new canes and the young ones supposedly don't fare as well. (Same as our society!)
To avoid fungal problems tie up canes using heavy string. Wrap it around the canes then twist it around the wire to prevent canes slipping when bushes are well established. Ten canes to a bush is usually sufficient, checking for spindly canes and removing them. After the third year canes may have reached 2 metres long and can be looped over the top-most wire as it may be looking like a fence at this stage. This can look effective and makes picking easier, especially if you have wired it at convenient picking heights.
In late Winter when the sap starts rising, prune off ends about 20cm from tips of canes. They will start to shoot early Spring. Black and red raspberries may be propagated by tip-layering. The tip of the current season's shoot is inserted vertically in the soil, say 10cm deep. Remember, suckers can become new plants too. Flowers on the main plant appear mid-Spring, while the fruit is ready for picking early Summer, usually for up to six weeks. New canes will be growing quickly now so be gentle in your picking. The bushes keep growing until the end of Summer or until Autumn cold creeps in.
They are susceptible to virus diseases such as Canespot. Again it is important to pick a good location - not too much wind but with some airflow. It helps to plant garlic, chives, nasturtiums, leeks, onions etc nearby. Chervil and chamomile help all plants and may be planted as companions. Blackberries and potatoes however, are not good companions. Raspberry flowers can also be attacked by thrips and light brown apple moths. White Root Disease causes plants to die out over a period of time, so dig out and burn and relocate new plants. Soils in which tomatoes, peppers, eggplants and potatoes have been grown recently should be avoided as these plants may infect the soil with verticillium wilt, a serious soil-borne disease of black and purple raspberries.
In full production, a raspberry plant can produce a kilogram of berries. To provide sufficient quantities for freezing or preserving, you may need twenty plants. Red raspberry plants produce many suckers which may soon become a thicket - much too wide for good fruit production and convenient management. Preferably, the fruiting row should not exceed a foot wide.
If raspberries fail, try loganberries -same family but they tolerate more heat. (Marry the sister so to speak.)