Gadenin日本語Get the appThe cycle in one view
The tree is evergreen, so there is no bare season to mark the year by. Instead it moves through overlapping stages: a flush of new growth, flowering on the wood grown last season, a long nut fill, and then the drop. Knowing which stage the tree is in tells you immediately whether to prune, feed, water or leave it entirely alone.
The whole run from open flower to fallen nut takes about six to seven months. That is why a cold night at flowering, or a dry fortnight in mid-fill, still shows up in the crop you sweep off the ground half a year later.
| Stage | What the tree is doing | Your job |
|---|---|---|
| Growth flush | Pushing new shoots that will flower next year | Feed lightly, rub off unwanted shoots by hand |
| Flowering | Long racemes open over several weeks | Keep soil evenly moist, no sprays, no pruning |
| Nut set and early drop | Shedding surplus nuts naturally | Watch for bug damage among the fallen nuts |
| Nut fill | Kernels building oil over months | Deep, regular watering; second feed |
| Nut drop | Husks split, nuts fall over 2 to 4 months | Gather weekly, husk within a day, dry |
| After harvest | Resting before the next flush | Prune, clear hanging husks, top up mulch |
Flowering: the weeks you must not interfere
The racemes are long, pale and trailing, and each carries dozens of small flowers of which only a tiny fraction will ever become nuts. That is normal. A raceme that produces five or ten nuts is doing well.
Two things wreck a flowering. One is dry soil, which causes whole racemes to shrivel and fall; keep the root zone evenly moist through this period. The other is spraying, which kills the bees doing the pollination. Whatever the pest, it can wait until petal fall.
Cold is the third risk and the one you cannot manage. A night near 28F (minus 2C) during flowering removes the crop for that year. If it happens, do not attempt to compensate with feed; wait for the next flush and accept a light season.
If you have a second macadamia of a different type nearby, note whether its flowering overlaps with the first. Cross pollination only helps when both trees are in flower at the same time.
Nut fill: water and one more feed
This is the long middle of the year and the stage most often neglected because nothing visible is happening. Inside each shell the kernel is slowly accumulating oil, and that process is driven by steady moisture. A dry fortnight now gives you small, light kernels that will not float in the water test.
Give a deep soak every seven to ten days without rain, wetting the soil to a foot (30 cm) down across the whole canopy area, and keep the mulch topped up so the surface roots stay cool.
- Second feed early in the fill Broadcast a light dressing of a low-phosphorus fertilizer over the mulch out to the canopy edge and water it in. Do not dig it in, and do not double the rate to catch up.
- Check the ties on staked trees The trunk thickens fastest at this time of year. Loosen and refit any strap that has begun to press into the bark, and re-firm stakes loosened by wind.
- Clear the harvest floor Cut the grass short under the canopy, rake out debris and cut back any branch resting on the soil, well before the first nuts fall.
- Watch the early drop Husk a sample of what falls. Clean, unmarked immature nuts are natural thinning; punctured or tunneled ones mean bugs and call for weekly collection from now on.
Drop season: the only stage with a deadline
Once husks start splitting, the tree sets the pace and you follow it. Gather everything on the ground once a week, and after any storm, because a nut left lying on damp soil molds and a nut left overnight feeds rats.
Husk within twenty-four hours, start the nuts air drying in a single layer, and keep each week's collection labeled with its date so batches do not get mixed at different stages of drying. Reduce watering during this period so the ground under the tree stays reasonably dry.
After harvest: the one pruning window
When the last nuts are off the ground, the tree is between crops and this is the moment to cut. Take out dead wood, crossing branches, storm damage and watershoots, lift the skirt if it has dropped, and stop well short of a fifth of the canopy.
At the same time, pick off any husks still clinging to the branches and bin them, since they carry fungal spores into next season. Top up the mulch across the whole root zone, keeping it clear of the trunk, and then leave the tree alone through the cool months. No feed, no pruning, and water only in a prolonged dry spell.
The four notes that make next year easier
Record the start and end of flowering, the date the first nut fell, the weight gathered in shell, and any night below 32F (0C). Those four lines, kept for three years, explain almost every good and bad season a garden macadamia will give you.
Add the dates you fed and pruned. Because pruning affects the crop a full year later and feeding affects it within months, the two are impossible to untangle from memory alone but obvious side by side on a page.