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Watering schedule

How often to water Macadamia (Macadamia integrifolia) — the schedule

Also called macadamia, smooth-shelled macadamia, Queensland nut.

More about macadamia

About Macadamia

Macadamia integrifolia · also called macadamia, smooth-shelled macadamia · edible

The smooth-shelled macadamia is a handsome subtropical evergreen yielding the world's richest dessert nut. Native to coastal Queensland rainforest, it wants warm, frost-free conditions, deep fertile acidic soil, and steady moisture. Trees are slow to bear (grafted plants in 4-6 years) but long-lived and productive, with glossy foliage and pendulous sprays of cream flowers.

Ideal humidity: 60-80%

Watch for — Phosphorus toxicity: Standard high-P fertilisers damage the proteoid roots, yellowing and scorching leaves. Always use low-phosphorus feeds formulated for Proteaceae or natives.

The watering schedule, season by season

Macadamia crops best on deep, regular soaks rather than light daily sprinkles — steady moisture at the roots is what fills and sizes the harvest. The base rhythm for macadamia is keep evenly moist; deep water weekly in dry spells, more during flowering and nut fill, but the real interval moves with the season, the light and the pot — so treat the figures below as a starting point and always confirm with the plant itself.

Shallow-rooted and intolerant of both drought and waterlogging. Mulch heavily and irrigate consistently through bloom and nut development; never let the root zone dry out completely.

Want this turned into a live reminder that adjusts to your home and the weather? The Growli watering calculator takes your pot size, light and season and returns a starting interval for macadamia in seconds.

How to tell macadamia needs water

A calendar is the worst way to water macadamia. Check the plant and the soil instead — for this species, look for these signals in order:

The most reliable single check is the first one on that list. When two signals agree, water; when they disagree, wait a day and look again — under-watering macadamia for a day is almost always safer than over-watering it.

Overwatering vs underwatering macadamia

The two failure modes can look alike at a glance, so check the soil weight and wetness before you decide. For macadamia specifically:

Signs you are overwatering

Signs you are underwatering

Shallow, frequent watering grows shallow roots and leaves macadamia prone to drought stress — cracked or woody roots, bitterness and premature bolting. Water deep and at the base, not little-and-often over the leaves.

Water quality notes

Tap water is fine for macadamia; consistency and depth matter far more than water type. Water early in the day at soil level to limit fungal disease.

Seasonal and environmental adjusters

Every figure above shifts with the conditions in your home. For macadamia, the levers that matter most are:

Pot choice is part of this too — work out the right size with the pot size calculator, since a pot that is too big stays wet long enough to rot the roots of macadamia.

Macadamia watering — frequently asked questions

How often should I water macadamia?

Water macadamia keep evenly moist; deep water weekly in dry spells, more during flowering and nut fill. Main season: aim for the equivalent of 2-3 cm of water per week as one or two deep soaks at the base, more in heat or during fruiting/sizing. Off-season: most do not overwinter outdoors — store, mulch, or grow undercover; container plants need only occasional water if dormant.

How do I know when macadamia needs water?

Push a finger 3-4 cm into the soil — if it comes back dust-dry, water now. Leaves wilt in the midday heat and do not fully recover by evening. The soil surface is cracked or pulling away from the bed/pot edge. The single most reliable test for macadamia is the first signal on that list — checking the soil or the plant directly always beats watering by the calendar.

What does an overwatered macadamia look like?

Yellowing lower leaves and waterlogged, airless soil. Root rot and wilting despite wet soil; fungal leaf spots from constantly wet foliage. Split or cracked fruit/roots from a sudden glut after drought. Shallow, frequent watering grows shallow roots and leaves macadamia prone to drought stress — cracked or woody roots, bitterness and premature bolting. Water deep and at the base, not little-and-often over the leaves.

What are the signs of an underwatered macadamia?

Persistent wilting, small or bitter produce, premature bolting. Blossom-end rot on tomatoes/peppers/squash from erratic moisture. Tough, woody or cracked roots in root crops.

Can I use tap water on macadamia?

Tap water is fine for macadamia; consistency and depth matter far more than water type. Water early in the day at soil level to limit fungal disease.

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