Down to earth: Multi-purpose shelter belts
Shelter trees
Autumn signals the end of the main growing season and offers us a good chance to tidy up, compost lots and appreciate the harvest. What stands out for me are the colours of autumn leaves as they lose their green chlorophyll before falling off to nourish the soil beneath.
It’s a good time to take stock of your shelter as most shrubs and trees can be planted or trimmed now. First consider the following principles:
1. POROSITY - Ideally 50%, to slow the wind, not stop it altogether.
2. HEIGHT - Preferably as tall as the situation allows. Deciduous trees can provide excellent shade and shelter, with little shading in winter. Protection from wind is calculated as approximately 20 times the height of the shelterbelt.
3. SPECIES - A mix of deciduous trees and native evergreens has the ideal 50% porosity.
4. SPACING - Single row shelter: 1.2 to 1.5m apart. Multiple rows and timber belts: 1.8 to 2.5m.
A shelter belt can also be multipurpose if you select a variety of species. Here are some other uses and examples:
Timber and Firewood: Tasmanian blackwood, European ash, Eucalyptus spp, Cupressus, Douglas fir and oaks are all good timber trees. Tagasaste and kanuka are great for firewood. Many trees (eg alders, willows) can be coppiced for ongoing firewood.
Human food production: Chestnuts, hazelnuts, stone pine, elderberry, feijoa, olive, etc. Perennial herbaceous crops such as globe artichoke could be grown at the base of shelterbelts.
Bee foraging: Eucalyptus, tagasaste, kowhai and lacebark.
Bird attractant: Crab apple, plum, rowan and many natives like pittosporum.
Animal fodder: Alders, tagasaste, linden and willows.
Nitrogen fixing: Alders, tagasaste and wattles contribute nitrogen to the soil.
Erosion control: Placed on unstable land trees will prevent soil subsidence and loss (eg by the coastline).
Mulching and composting materials: Regular trimmings can be shredded to provide carbon for composting, especially for intensive fruits.
Aesthetics: Choose trees for form, flower and colour, especially in autumn.
Fruit care
Complete pruning, especially stonefruit.
Harvest fruit. Remove diseased or insect-infested fruit and leaves from around trees.
Sow orchard understorey plants and plant spring bulbs.
Feed orchard with dolomite lime, rock phosphate, manure, woody compost, mulch.
Prepare new strawberry beds. Let runners replace old plants.
Spray fruits with liquid seaweed as a tonic.
Also spray citrus with all-purpose oil for scale insect, thrips or aphid (or use garlic and pyrethrum).
Prune citrus when harvesting.
Herb care:
Harvest herb seed.
Sow seed of rosemary, thyme and chives.
Plant parsley.
Transplant rooted cuttings from last year. Take cuttings of rosemary, sage, lavender etc.
Water, weed and mulch.
Vegetable care
Prepare garlic beds. Plant rocambole (serpent garlic).
Last chance to sow green manure crops like vetch, oats and mustard into beds unused for winter plantings.
Harvest pumpkins when tendrils and stalks brown off. Collect dry beans for seed. Shell out and dry in airing cupboard before storing with some rice.
Save seed from best salads, silverbeet, leeks etc. (Process, clean, dry, freeze, store).
Prepare ground (add lime and compost) for broad beans and peas and sow.
Plant winter brassicas into fertile bed. Spray Bt vs caterpillars.
Sow/plant salads and winter greens for ongoing supply, eg corn salad.
Sow and plant lots of flowers to attract beneficial insects.
Hothouse: Clean for better light. Liquid fertilise weekly. Keep well ventilated. Spray diluted milk solution vs powdery mildew.
For transplanting: All seeds 27 April. Leafy greens (summer spinach, spinach beet, lettuce, endive, cabbages), red onions, broccoli, cauliflower. Flowers, eg pansy.
Sow direct: All seeds 27 April. Mesclun salad. Peas. Radish, spring onions, spring carrots, swede, turnip (also 25th – 28th April). Flowers, eg poppies.
Plant: Salad greens, silverbeet/chard, spinach, cabbages. Flowers, eg everlasting daisy.
General garden care
Lime the lawn.
Take a soil test for garden and orchard areas (try www.hillslaboratories) and organise minerals to offset deficiencies.
Make lots of compost. Turn heaps.
Prune trees and shrubs after flowering, including roses.
Collect leaves for composting.
Collect seaweed/seagrass.
Sol Morgan, GroWise Consultancy
