Norfolk Island pine care: light, water and a cool room

Light

Give it the brightest spot in the house. The Illinois Extension lists the Norfolk Island pine as a high or bright light plant, about 300 foot-candles, which you find directly in front of an east or west window or within 5 feet of a south one. Missouri Botanical Garden and NC State say full sun is normally best indoors for compact, symmetrical growth, with light afternoon shade if the foliage starts to bleach yellow. UF/IFAS puts it plainly: indoors this tree needs quite bright light, and one that is not thriving is most likely short of light or humidity.

Even growth needs even light. UF/IFAS recommends turning the plant every week or so to keep it growing straight and upright, because a tree lit from one side leans toward the glass and fills out on that side only. A dark corner is a slow decline rather than a home: NC State says indoor plants can tolerate very low light for two or three years before leaf drop and the loss of lower branches set in.

Water

NC State advises watering regularly from spring to autumn while avoiding soil that is too wet, and Missouri Botanical Garden asks you to avoid soils that are either too wet or too dry. UF/IFAS adds that Norfolk Island pines do not appreciate being too wet and that overwatering is not the way to give them the humidity they like. In practice, water thoroughly when the top inch of mix feels dry, let the pot drain completely, and empty the saucer.

Winter changes the rhythm. NC State says to water sparingly in winter, when growth slows in short days and a pot in a cool room dries slowly. Check by touch, as the Illinois Extension recommends, testing about two inches down, and use room-temperature water rather than cold. Missouri Botanical Garden lists mushroom root rot among this tree's problems, one more reason to let the mix dry a little between waterings.

Soil and pH

Missouri Botanical Garden and NC State describe the same container medium: fertile, porous, sandy, peaty, slightly acidic and well drained. A peat-based houseplant mix opened up with coarse sand or perlite fits that description. Neither source gives a numeric pH, only slightly acidic, so there is no need to test or amend beyond using a fresh peat-based mix. Whatever you choose, the pot needs a drainage hole.

Humidity

Here the sources disagree. UF/IFAS stresses humidity: the tree is a tropical plant that thrives on it, and a saucer filled with water and gravel, with the pot sitting above the water, creates a humid microclimate. NC State and Missouri Botanical Garden say that as a houseplant it usually adapts to the warm, dry air of most homes and offices, though NC State suggests misting in heated rooms in winter. The practical middle ground is a pebble tray all year and occasional misting while the heating runs, never extra water in the pot.

Temperature

A Norfolk Island pine likes it cooler than most houseplants. NC State and Missouri Botanical Garden recommend a bright, cool room at 55 to 65°F (13 to 18°C). Outdoors, UF/IFAS says it cannot tolerate temperatures below 35°F (2°C), which puts the northern edge of its range around Orlando in Florida. Treat 35°F as a survival limit, not a target, and keep the tree away from heating vents and cold drafts, which the Illinois Extension warns can damage foliage.

Fertilizer

NC State and Missouri Botanical Garden suggest weekly or biweekly applications of dilute liquid fertilizer from spring through fall. Neither gives the dilution, so we suggest half the label rate as a cautious reading of dilute, given how often it goes on. Stop in winter, and leach the pot with plenty of plain water every four to six months, as the Illinois Extension recommends, so fertilizer salts do not build up in the mix.

Work out the dose for your watering can with the fertilizer dilution calculator →

Repotting

Slow growth means infrequent repotting. Watch for the Illinois Extension's signs: roots growing through the drainage holes or on the surface, a soil mass filled with roots, smaller new growth, or wilting between normal waterings. Repot in spring or early summer, going up 1 or 2 inches in diameter as Clemson advises, and keep the trunk at the same depth it grew before. For a tall tree in a pot too heavy to lift, Clemson's alternative is to replace the top 2 or 3 inches of soil with fresh mix every other year or so.

• Roots grow through the drainage holes or appear on the surface
• The soil mass is filled with roots
• The plant wilts between normal waterings

Propagation

Propagation is a slow project for this tree. NC State lists seed as the recommended method, and Missouri Botanical Garden notes that seed-grown trees typically have widely spaced tiers of branches, less ornamental than trees raised from terminal cuttings. Seed is sown in moist, sandy, peaty soil, according to Missouri Botanical Garden. For most owners, buying a young tree is far quicker than raising one, and the effort is better spent keeping an existing tree in good light.

Methods: Seed, Terminal cuttings · Best season: spring to summer, while the tree is growing.

Common problems

NC State calls the tree generally pest free but susceptible to scale, sooty mold and leaf spot, and Missouri Botanical Garden adds spider mites and mushroom root rot. Indoors, most complaints come down to light, water and dry air rather than pests. Lower branches yellowing and dropping after a few years in dim light is NC State's warning sign. A yellow-tinted bleach on the sunny side points to harsh afternoon sun, and crisp, browning tips usually follow dry heated air or a pot left dry too long. Sooty mold, a black film on the branches, typically grows on the sticky residue that scale insects leave, so deal with the scale first.

Not sure which one it is? Try the plant problem diagnosis tool →

Is the Norfolk Island pine toxic to cats and dogs?

The ASPCA lists the Norfolk Island pine as non-toxic to dogs, cats and horses. Its entry is filed under the name Australian Pine, but the scientific name it gives is Araucaria heterophylla, and it lists Norfolk Pine, House Pine and Norfolk Island Pine as additional common names, so it is the same plant. NC State's profile carries no poison warning either. Non-toxic does not mean edible: Missouri Botanical Garden describes the needles as having sharp, incurved points, so discourage chewing, and call your veterinarian if a pet seems unwell after eating some.

Check any other plant against the ASPCA lists →