Mole Station Native NurseryGardening with native plants1. Drainage Many native plants require well drained soil. If your soil stays wet sometimes for weeks, it may be sensible to check out those plants which can withstand waterlogged conditions. These include melaleucas and callistemons and many eucalypts. A good guide is to note plants which grow happily along creek banks e.g. Eucalyptus camaldulensis (River Gum), Casuarina cunninghamiana (River Oak) or Callistemon viminalis (Weeping Bottlebrush). For those plants requiring good drainage such as grevilleas or correas, it may be necessary to build raised beds or a mound on which to grow the plants. As a general rule many native plants growing near the coast can withstand poorly drained soils and humidity, while plants native to the dryer interior prefer sandier well drained soils and a dry atmosphere. 2. Pruning Usually native plants should be pruned after flowering though pruning a little and often is very beneficial. While small, tip prune each month or so to encourage a compact centre. Later, pruning once or twice a year may be all that is required. Most importantly, prune early to avoid bare ugly branches at the base of the plant. Most eucalypts do not require pruning and naturally drop their lower branches as they grow. Pruning off these lower limbs may cause the tree to fall over. 3. Mulch and Weed Control Many natives dislike having their roots disturbed, resulting in sudden death. The safest way to deal with weeds is to avoid them altogether, particularly around the base of the plant. Weed mat with a cross cut where the plant is to be planted is a good way to achieve this. Placing newspapers ten sheets thick around the plant and close to the trunk is also effective as a weed barrier. The next step is to cover with whatever mulch is to be used such as wood chips, hay or lawn clippings making sure the material is not actually in contact with the trunk. In frosty situations, a thick mulch can actually increase the risk of frost damage. Ideally a good thick mulch should be applied in spring after the frosts have finished. The mulch then helps keep the roots cool and conserves moisture during the summer months but by winter will be thinner and more likely to allow the sun to warm up the ground. For low maintenance it is advisable to mulch an entire area of the garden rather than around each plant. Mowing is simpler and it is easier to deter the grass from one large bed than many smaller ones. Many natives do not compete well with grass growing close to the trunk.They become stressed and may succumb to diseases such as scale. 4. Fertilising It is probably more important to feed the soil rather than the plant. Adding organic matter to the soil will supply natives with the nutrients they require without overfeeding. Over fertilising may result in root burn or over vigorous growth leading to plants which blow over easily. Blood and bone is usually beneficial when placed in the hole prior to planting. Beware of mushroom compost as it may be too alkaline, many natives preferring an acidic soil with a pH between 5 and 6.5. Most natives resent high levels of phosphorus resulting in a yellowing of the leaves. To correct this it is necessary to apply an acidifying fertiliser, such as iron sulphate or iron chelate. The following is a useful recipe for natives which have yellow growth tips and/or dying leaf edges and will also give them a boost: 2 teaspoons iron sulphate 2 teaspoons magnesium sulphate (epsom salts) 2 teaspoons ammonium sulphate (Granam) mixed together in a large watering can (10 lt.) Iron induced chlorosis (as this condition is called) may also be the result of too much water, so avoid extra watering. 5. Water Requirements Some idea of the natural environment of the plant will indicate whether supplementary watering is required or not. Here are a few tips:
6. Pests It is important to plant a range of different native species to attain a balance of bird species. A lower storey will provide shelter for smaller birds such as honeyeaters, finches and silver eyes. Prickly grevilleas, while providing shelter for small birds, also provide food and nesting areas. They are very efficient at keeping insect pests under control. A plant which is stressed will often become a target for disease including scale and associated sooty mould. A spray of white oil and malathion will provide temporary control but improved growing conditions such as increased drainage or mulching to prevent weed competition may be a more enduring option. In areas where scarab beetles (e.g. Christmas beetles) attack eucalypts it may be simplest to plant those eucalypts which are not so palatable such as Eucalyptus acaciiformis or E. parvifolia. Some compact melaleucas and leptospermums are susceptible to the webbing caterpillar which lives in a web inside the shrub and may ultimately defoliate the plant. Check these plants frequently and pull out the webs or use a systemic insecticide. 7. Frost Protection Many of the smaller native shrubs and creepers including boronias, hardenbergias and kennedias naturally grow in situations sheltered by taller trees. Though in full sun they often thrive, winter frosts may kill them. If planting in an exposed situation, the following suggestions may help:
8. Garden Design Though garden design is of course only limited by your imagination, the following suggestions may help with the practicalities of deciding which plant to put where:
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