Pomegranate

Steady water while fruit matures, or the fruit splits

Once fruit is sizing and coloring, water evenly and often rather than in big swings - drip is far better than overhead. Do not let the plant dry down hard and then flood it, and ease off heavy irrigation as harvest nears, especially if rain is coming. A ripening pomegranate has a rind that has already stopped expanding. When a drought-stressed plant suddenly takes up a surge of water, the arils swell against that fixed rind and it cracks - which is also how rot organisms get inside. Drought tolerance keeps the plant alive; it does not keep the fruit whole.

Feed in spring, then stop - late nitrogen costs you color

Apply about 1 ounce of 10-10-10 per foot of bush height, broadcast out at the dripline, three times a year: early spring, late spring, and summer. Cap each application at about 8 ounces once the plant reaches 8 feet. If leaves show zinc deficiency, add a foliar zinc application in spring after fruit set. Do not carry nitrogen into late summer or early fall. Nitrogen arriving in late summer or early fall pushes the plant back into leaf and shoot growth exactly when it should be loading sugar and pigment into fruit - UGA reports a detrimental impact on fruit color and size, and Nevada Extension adds that late nitrogen drives excessive vegetative growth, reduces fruit production, and delays maturity and color.

Dormant prune: open the vase, take the suckers, keep it light

While the plant is dormant and before bud break, remove dead and crossing wood and cut out unneeded basal suckers, opening the plant to a vase shape. For a multi-trunk shrub, select and keep five or six vigorous suckers as your main trunks. When a trunk is lost or damaged by freeze, remove it and train a vigorous new sucker to take its place. Prune lightly and regularly - do not head the whole plant back hard. Pomegranate carries its short fruiting spurs primarily on two- and three-year-old wood, mostly around the outer perimeter, so heavy cutting removes the very wood that would have carried the crop, while light annual pruning keeps young spurs coming. Multiple trunks are worth keeping in cold zones because when a freeze damages part of the plant you can simply remove the damaged trunks and train a sucker to replace them without losing the whole plant, which a single-trunk tree cannot do.

Clean up mummies and deadwood after harvest to starve gray mold

After the last fruit is off, strip every leftover and mummified fruit from the plant and off the ground, and cut out dead branches. Do not compost mummies next to the plant. Botrytis infects at bloom, when spores settle on the dying stamens inside the flower during rain, dew, or fog - then it goes dormant and waits, invisible, until moisture at the blossom end of ripening fruit wakes it up. You cannot spray your way out of this: pomegranate's long bloom makes bloom sprays impractical and the fruit's crown physically shields the blossom end from later coverage. Removing the old fruit and dead wood that carry the spore load into next season is the control that actually works.

Scout for leaffooted bug as fruit colors up

From the time fruit begins coloring through harvest, walk the plant weekly and look for large brown bugs with flared, leaf-like hind legs, and for clustered masses of red-orange nymphs sitting directly on the fruit. Cut open a suspect fruit: brown spots on the inside of the rind mean they have been feeding. Leaffooted bugs pierce the rind with a needle-like proboscis, and the damage barely shows from outside while the arils beneath wither and opportunistic soft-rot organisms follow the wound in. All life stages aggregate on fruit late in the season, so numbers climb fast right when the crop is most valuable.

Leaffooted bug: pyrethrins only if aggregations are on the fruit

If scouting turns up nymph masses or numerous adults on ripening fruit, treat with pyrethrins (PyGanic), directing the spray at the clusters. Treat only when you have actually found the bugs - this is a rescue treatment, not a calendar spray. Pyrethrins knock down the exposed nymph aggregations on contact and break down quickly, which is what makes them usable this close to picking - but they kill on contact only, so they do nothing preventively and there is no reason to spray a plant that has no bugs on it.

⚠ Pyrethrins are toxic to bees. Pomegranate flowers over a long, staggered period, so check for open blossoms and spray only at dusk when bees are not foraging, never over open flowers. PyGanic EC 1.4 has no pre-harvest interval beyond letting the spray dry, and a 12-hour restricted-entry interval. Avoid clothianidin (Belay), whose label bars application during bloom, and methomyl (Lannate), a restricted-use material not appropriate for home plantings.

Guard against hard freezes below about 12F

Where winter lows reach the low teens, grow multi-trunked rather than single-trunked at the cold edge of the range. In frost-prone spots, paint the trunk bark with flat white latex paint to damp the swing between day and night temperature extremes. If a freeze damages branches, remove them and train a vigorous sucker to take their place. Most cultivars are hardy to about 12F and are severely injured below it, with the hardiest types coming through undamaged to roughly 7F. The plant is most cold-resistant in midwinter and more vulnerable before it reaches full dormancy in fall and again at bud break in spring. A multi-trunk plant is what keeps pomegranate viable at the cold margin: lose a trunk and you train up a sucker, where a single-trunk tree has to be replaced outright.

Pick by sound and color - it will not ripen after you pick it

Harvest when the fruit has taken its full cultivar color and gives a metallic ting rather than a dull thud when you tap it. Cut the stem with shears instead of pulling, and set fruit down gently. Do not leave fully ripe fruit hanging in hope of more sweetness, especially with rain forecast. A picked pomegranate cannot ripen further - it will not respond even to ethylene treatment - so everything the fruit will ever be is decided on the plant. But an over-mature fruit left hanging cracks open in rain, wind, or humidity swings, which is why the window is real and narrow. The metallic ring is the sound of arils packed tight against a rind that is done growing. Fruit bruises easily and shows it later.