Subtropical orchards
If you enjoy fruit like citrus and tamarillos and live on a low-frost property, then you can create a subtropical orchard in your own backyard. Here’s how:
1. Pick a warm, semi-sunny, sheltered spot for the orchard. Other trees may have to be cut down to provide more light. Low-lying spots may get more frosts, so aren’t ideal. Ridges may be too windy and dry out too much.
2. Shelter is important. Your subtropical fruits could be integrated into a patch of regrown bush. If you don’t have shelter, then plant lots of tagasaste (tree lucerne), as it can also be used as mulch, to attract bees and add nitrogen to the soil. Otherwise make shadecloth frames around each tree.
3. Varieties and spacing: Plant the largest fruits first. Avocados, cherimoya (custard apple), casimiroa (white sapote) and macadamia form the canopy and need six metres between trees. Next come subcanopy fruits such as loquat and citrus (grapefruit, orange), spaced five metres apart. Also plant tamarillos, tropical guava, mountain pawpaw (papaya), banana (lady finger variety—bag fruits to aid ripening), citrus (mandarin, tangelo, lemon, lemonade, lime) at three to five-metre spacings. Then follows a low shrub layer of strawberry guava, naranjilla, cape gooseberry, and Chilean guava (strawberry myrtle), needing one to two metres between them. Pepino and comfrey form the ground cover. Passionfruit (black) grow up the taller tree species.
4. Subtropical fruits are forest plants and like heaps of organic matter (and no grass/weeds). Mulch out the weeds first with lots of cardboard, and cover with woody material like bark, shreddings, or even better bark-based compost. If the area is too large to mulch, then mulch at least 1.5 metres out from where the fruits are planted, and expand the area as they grow.
5. Plan the orchard based on the spacings above. Interplanting larger trees with smaller species resembles a forest ecosystem. Plant subtropicals in spring and incorporate generous amounts of organic matter. Boron and other rock minerals (try NZ Fert compound fertiliser) can be mixed into the hole. Mound up the plants if drainage is poor and add gypsum and coarse sand to the mix. If planting on a slope, then make swales below the trees with soil, wood or rocks. Mulch around the plants with woody material.
6. Ensure water is adequate during dry periods. You could run grey/black water into the orchard via seepage lines, or set up drip irrigation. Add generous quantities of compost and decomposed animal manures to each plant annually. Prune out tagasaste or natives as your fruit trees get bigger and need more light. Regularly prune branches, shred and mulch. Also use seagrass/seaweed mulch for trace minerals. If grass still appears between plantings, mow it and use it as mulch. Watch for deficiencies. A soil or plant test will let you know what nutrients are missing. Adjust annual fertility applications.
7. Over the next few years you’ll be provided with an abundance of subtropical bounty. Enjoy!
Fruit care
Complete planting of deciduous fruit trees/shrubs. Stake and tie (bicycle innertubes are great!). Protect from wind and animals.
Sow understorey plants under fruit trees or in borders to encourage beneficial insects and improve soil health (see Kings Seeds for mixes).
Mulch fruits with woody compost and manures (especially citrus and peaches).
Prepare new strawberry beds. Add compost, leaf mould and mulch with pine needles.
Prune citrus when harvesting. Frost protect young plants. Spray citrus with all-purpose oil for scale insect. Mulch with manure and woody compost.
Divide rhubarb.
Spray everything with diluted seaweed solution. Copper spray stone fruit vs brown rot, or pipfruit vs black spot. Spray lime sulphur vs peach leaf curl, black spot, powdery mildew, scale, mites and borers.
Herb care
Transplant rooted cuttings from last year.
Weed herb beds in preparation for sowing annual herbs like parsley.
Sow herb seed indoors.
Vegetable Care
Make loads of compost as you complete bed preparations.
Begin main spring sowings indoors, especially tomatoes, peppers and eggplants.
Dig in green manures or cut and cover with black plastic for mid-spring plantings.
Plant early potatoes into organic-matter-rich soil. Protect from frost.
Prepare beds for hot crops (tomatoes, cucumbers, etc). Add lots of compost, blood and bone and organic compound NZ fertiliser.
Continue preparing seed beds for upcoming sowings of root crops, etc.
Plant asparagus.
Sow/plant beneficial flowers, eg phacelia.
Hothouse: Main sowings into punnets/trays. Watch for snails. Make indoor compost to raise temperature. Plant early tomatoes and cucumbers into rich beds.
For transplanting: All seeds 21st September. Leafy greens (spinach, spinach beet, silverbeet/chard, lettuce, endive, kohlrabi, cabbages)(best 5th-6th September). Tomatoes, peppers, eggplants (bottom heat), cucumbers, zucchini and pumpkins (also 7th September). Broccoli, cauliflower (also 12th Sept). Flowers, eg scabiosa.
Sow direct: All seeds 21st September. Mesclun salad and spring onions. Peas and French beans (cover). Radish, carrots, beetroot (cover), kohlrabi, turnips, swede (also 9th – 11th September). Flowers, eg sweet peas.
Plant: Best 1st Septmber. Salad greens, spinach, broccoli, cauliflower and cabbages. Early potatoes in frost-free areas. Onions. Flowers, eg tip cuttings of chrysanthemums into sand under cover.
General garden care
Mulch perennial gardens with bark.
Mulch-mow lawn.
Soil test garden and orchard areas (try www.hillslaboratories) and organise minerals to offset deficiencies.
Collect seaweed/seagrass.
Sol Morgan, GroWise Consultancy
