Macadamia
Macadamia integrifolia
Grown under heated glass with no margin for frost, and it resents a hard cut as much as a cold night.
- Type
- Fruit · Perennial
- Botanical family
- Mixed / other
- Foliage color
- Green
- Sunlight
- Full sun; the brightest place a heated greenhouse can offer.
- Watering
- Water regularly but never to waterlogging, easing back in winter.
- Feeding
- A balanced feed every two weeks, with trace elements included.
- Frost tolerant
- Yes
- Flowering
- February
- Pruning
- Shape it lightly in spring; heavy cuts are not welcome.
- Overwintering
- Heated glass above 10°C — there is no frost tolerance to fall back on.
- Feb–Mar Flowering
- Mar–Sep Fruit Set
- Sep–Dec Harvest
- Jan–Feb Harvest
- Plant spacing
- 29 ft 6 in
- In-row spacing
- 29 ft 6 in
- Between rows
- 32 ft 10 in
- Square-foot density
- Not suited to SFG
- Root system
- A fine surface mat, and nothing below it
- Working depth
- 6–20 in
- Spread
- 16–25 ft across, about 1–1.5× the width of the plant
- Shallowest pot
- 16 in of soil
Hair-fine roots in a shallow felt, with no deep anchor to fall back on. It cannot chase water, so it is the first casualty of a drought and the first thing killed by a hoe. Mulch it, never cultivate around it, and never let it go dry in its first two summers.
It makes dense brush-like proteoid roots in the surface litter instead of a deep anchor, which is efficient at finding phosphorus and hopeless in a gale: mature macadamias blow over. Mulch, never dig, and never feed it a high-phosphorus fertilizer.
Figures recorded for Macadamia itself. Roots follow the soil either way: a compacted pan, a high water table or heavy clay stops them well short of any of it, and deep open ground lets them go further.
- Cats
- Not on a list we read
- Dogs
- Recorded toxic
Recorded as toxic to dogs by ASPCA.
The ASPCA names dogs only, so the cat verdict is silence rather than safety. The same species is also filed as Australian Nut and Queensland Nut.
- Mealybugs Mealybug in white cottony masses
- Scale insects Scale insects, brown bumps trailing sticky honeydew
- Spider mites Red spider mite, webbing up when the air runs dry
- Anthracnose Anthracnose, dark spots on leaves and nuts alike
- Phytophthora root and foot rot Phytophthora root rot, which yellows the tree and then collapses it
Beneficial predators that hunt this plant's pests — grow their favourite flowers nearby to recruit them. companion plant
- Ladybird (lady beetle) Coccinellidae
The gardener’s favorite ally: adults and their alligator-shaped larvae each eat thousands of aphids, plus scale, mealybugs, and other soft-bodied sap-suckers. Grow flat, open flowers for the adults and never spray a colony that ladybird larvae are already working.
- Green lacewing Chrysoperla carnea
Its bristly larvae — "aphid lions" — impale aphids, mealybugs, thrips, and mite colonies, eating hundreds a week. Adults feed on nectar and pollen from small open flowers and overwinter in hollow stems left standing.
- Hoverfly Syrphidae
Bee-mimicking flies whose legless larvae graze aphid colonies clean while the adults pollinate. A ribbon of shallow, nectar-rich flowers kept in bloom all season recruits wave after wave of them.
- Big-eyed bug Geocoris spp.Hunts Spider mites
A stubby 3 mm bug with enormous wrap-around eyes, working the soil surface and the low foliage for aphids, mites, thrips and insect eggs. It is the main natural check on chinch bugs in a lawn and it is killed outright by insecticide.
- Minute pirate bug Orius spp.Hunts Spider mites
A pinhead-sized true bug that is the best natural check on thrips, and happily spears aphids, mites, and insect eggs too. It needs pollen when prey is scarce, so keep something flowering nearby.
- Predatory mites Phytoseiulus & AmblyseiusHunts Spider mites
Fast orange mites that hunt spider mites egg-by-egg, and cousins that clear thrips and fungus-gnat larvae. Sold as a biological control for greenhouses; outdoors they follow humidity — mist and mulch, don’t dust with sulfur.
- Rove beetle StaphylinidaeHunts Spider mites
Slim, quick beetles with short wing cases that hunt in soil and litter, taking root-fly eggs and larvae, fungus-gnat larvae, and mites. Mulch and undisturbed ground keep them resident year-round.
Green-leaved fruit, like this one.
The Cottage Garden Companion — the gardener's herbarium at cottagegardencompanion.com