Rhopalostylis

( rope - ah - low - STYE - lis )

At-A-Glance Information

This genus of palms includes species which need full sun to partial shade and regular water to perform well in the landscape. These palms are native to the South Pacific, and have long, clean trunks marked with rings. Long fronds top trunks, and are green, stiff, and can reach up to 10 to 16 feet long. Use these plants in the landscape in cool, coastal or temperate gardens. They can serve as specimens, grouped plantings, or as accents in tropical gardens or around pools. They can also be grown successfully in containers.

rhopalostylis Species and Varietals

This genus includes just two species and is a member of the plant family Arecaceae. The palms in this genus are closely related to those in Hedyscepe (Umbrella Palm). Rhopalostylis grows best in USDA hardiness zones 9b-11 or Sunset growing zones 17, 23, 24, H1 and H2. To find your zone, click here: Zone Map.

Rhopalostylis baueri (Norfolk Island Palm, Niau, Kermadec Nikau)
Native to Norfolk Island, this 50 foot tall, 20 foot wide feather palm has beautiful curving, arching leaves. At maturity, they can reach up to 30 to 40 feet tall with a canopy spread of between 10 and 15 feet. This species is native to Norfolk Island, Australia and the Kermadec Islands, a chain northeast of New Zealand.

Rhopalostylis sapida (Nikau Palm, Shaving Brush Palm, Nikau, Feather Duster Palm)
This species is native to New Zealand and reaches 30 feet tall and 15 feet wide at maturity. Feathery leaves stand upright from the top of the trunk. Trunks are grey-green with light-colored scars from previous leaves. This is a great small-space palm and can also thrive in containers.

Caring for rhopalostylis

The first step in caring for a Rhopalostylis palm tree is to choose the right spot in the landscape to install it. These plants prefer partial shade to filtered sun, as their fronds sunburn easily. They are typically found growing in tropical forest understory. Rhopalostylis appreciate humid conditions, so keep them away from areas with drying, cool winds. They prefer soil to be rich and well-draining. A sandy loam or a palm-specific potting substrate is recommended for Nikau Palms. Ensure that soil is well-draining, rich in nutrients, and has a pH of between 6.0 and 7.5 (slightly acidic to neutral). If local soils are particularly poor in nutrients or do not drain well, make sure to amend the planting area with plenty of organic compost before installing. Apply a layer of mulch around the planting area to suppress weed growth, maintain consistent soil temperatures, and to increase soil moisture retention. Water new plantings regularly as they establish a strong root system in their new home. When mature, these palms require consistently moist soil and dislike drying out completely between waterings. Do not allow soil to become waterlogged, however, as this will quickly lead to root rot.

These trees, although not heavy feeders, do appreciate an application of organic compost yearly in springtime to support the year's growth and flowering. These trees do not need to be pruned; they keep a relatively attractive habit when left to their own devices and are very slow-growing. Simply remove dead, damaged, diseased, or errant fronds when necessary. Removing too much foliage at one time can stress out the plant and inhibit further growth; never remove more than a third of the canopy at any time, and avoid cutting into healthy fronds. Rhopalostylis palms can be expected to survive in the landscape for hundreds of years before needing to be replaced. Visible trunk formation does not begin until these palms are between 10 and 40 years old.

Caring for Rhopalostylis in Containers
Rhopalostylis , or Nikau Palms, are wonderful in the ground but can also be grown in containers. Choose a container that is at least a few inches wider and deeper than the nursery pot or root ball. Ensure that the pot has adequate drainage holes on the bottom to allow for excess water to flow away. Fill with a well-draining potting mix amended with organic material and perlite, and top with a layer of mulch to suppress weed growth, maintain consistent soil temperatures, and to increase soil moisture retention. Water regularly as the plant establishes itself in its new home. Once established, waterings can be lessened. Rhopalostylis plants grown in containers will need more frequent irrigation than those grown in the ground. As a general rule of thumb, water whenever the top few inches of soil feels dry to the touch. Prune to remove dead, damaged, or diseased foliage at any time during the growing season. Every two years, check the bottom of the pot to ensure that the plant is not outgrowing its root space. If roots are growing through the drainage holes in the bottom of the container, it is a good indication that it needs to be potted up; choose a slightly larger container and repot. These palms will actually perform better when slightly root-bound.

Propagation

Rhopalostylis are best propagated from seed. These palms do not produce offsets from their base, and are almost exclusively propagated from fresh seeds. To propagate your Noikau Palm, follow the instructions below:

Propagating Rhopalostylis by Seed

Keep in mind that the plant you get from seed will not necessarily mimic all of the characteristics of the parent plant. To propagate by seed, you will need a paper bag, a pot or tray filled with well-draining compost or other organic material, a spray bottle and a fork. The best potting medium for seed germination is a light blend of 1/3 pasteurized soil or compost, 1/3 sand, vermiculite or perlite, and 1/3 coconut coir or peat moss.
Harvest your seeds. Fruits produced by mature trees (that are at least 10 years old) will produce seeds. Fruits are ready to drop when they are deep red to carmine. They are egg-shaped and contain between 3 and 12 seeds each. Remove seeds from fruits and rinse off any flesh.
Water your prepared seed tray or pot filled with soil, and ensure that good drainage is occurring. Place your seeds in your prepared pot or seed tray about a half-inch under the soil surface. Cover them with soil and water with your spray bottle. Place your tray of seeds in a warm area that receives bright, indirect light. A greenhouse is the most ideal climate, but a planting tray inside a window will do as well. Germination usually takes between 5 and 18 months from sowing. Once you begin to see seedlings sprout and they are able to be handled, transplant them to their own individual 3-inch pots, filled with the same potting medium as described in Step 1. Loosen the seedlings from the potting medium by digging down with the tines of your fork about an inch and a half, gently working the seedling up until it is out. Then, replant the seedling in its individual pot.
Keep the seedling's potting medium moist, but not wet, by spraying the soil with your spray bottle. Keep your new plant in an area with bright light (though not direct sunlight) and temperatures between 55 and 70 degrees Fahrenheit. Ensure that the soil stays moist, but not wet, until the next spring (after the danger of frost has passed), when you can transplant it to its new home. New seedlings will need to be protected from extreme heat, frost, and light for the first 5 years of life; it is recommended that in cooler climates they are grown in containers and brought indoors during inclement weather.