Dwarf pittosporums are compact evergreen shrubs with glossy leaves, a naturally mounded shape and fragrant spring flowers, and they rarely need much pruning.1Three Timbers Landscape Materials. Dwarf Pittosporum Shrub Phoenix | Pittosporum tobira | Three Timbers A handful of named varieties cover most garden needs, from plain dark green mounds to cream-edged and perfectly round forms. The variety matters less for success than the ground it goes into, because every dwarf pittosporum shares one weakness: soggy soil.
The Most Popular Dwarf Pittosporum Varieties Compared
- ‘Wheeler’s Dwarf’: grows about 3 to 4 feet tall and 4 to 5 feet wide, with shiny dark green leaves in a dense mound.2Home & Garden Information Center. Pittosporum3EDIS. Pittosporum tobira ‘Wheeleri’: Wheeler’s Dwarf Pittosporum
- Cream De Mint (‘Shima’): slowly reaches 2 to 2.5 feet tall and wide, with cream-edged leaves.4Home & Garden Information Center. Pittosporum
- MoJo: slowly grows 2 to 3 feet tall and 3 to 4 feet wide, with glossy cream-edged leaves.5Home & Garden Information Center. Pittosporum
- ‘Golf Ball’: a different species, Pittosporum tenuifolium, that forms a dense, naturally round ball with little pruning.6Jackson’s Nurseries. Popular Dwarf Pittosporum Varieties for Your Landscape7Plantmark. Pittosporum tenuifolium Golf Ball
Wheeler’s Dwarf is the plain green workhorse. Its leaves are thick and leathery, about 4 inches long.8EDIS. Pittosporum tobira ‘Wheeleri’: Wheeler’s Dwarf Pittosporum It grows at a moderate rate into a dense, rounded form.9EDIS. Pittosporum tobira ‘Wheeleri’ Wheeler’s Dwarf Pittosporum With age, it can even be pruned into a miniature tree in a container.10EDIS. Pittosporum tobira ‘Wheeleri’: Wheeler’s Dwarf Pittosporum
The “variegated” types, Cream De Mint and MoJo, have leaves with two colors, here green with creamy white edges. Cream De Mint changes through the year: its new growth emerges light green or green-gold in spring, then turns silvery green with cream edges.11Home & Garden Information Center. Pittosporum12Monrovia. Cream De Mint Dwarf Pittosporum It grows in full or partial sun.13Monrovia. Cream De Mint Dwarf Pittosporum
A wide bed under windows suits Wheeler’s Dwarf, which spreads more than it climbs. Golf Ball fits formal designs where you want neat spheres without clipping, and the cream-edged types brighten dark green plantings and shady corners as accents.
Between the two cream-edged plants, Cream De Mint fits tight spaces such as a small pot or narrow strip. MoJo spreads wider, so it gives more coverage in a bed of modest size.
Read the plant tag carefully. Names often appear in quotation marks, such as ‘Wheeler’s Dwarf’, and a trademarked name like MoJo or Cream De Mint may be printed too, so check the botanical name as well. Golf Ball is Pittosporum tenuifolium, while the other three are forms of the tobira species, and the two groups differ in leaf shape and cold behavior. Sizes on tags are mature sizes after many years, so a one-gallon pot will look much smaller than the number printed on it.
Space plants by mature width, not pot size, since young plants look sparse at first. Wheeler’s Dwarf needs about 4 to 5 feet between centers to avoid crowding.
Wheeler’s Dwarf, at a moderate growth rate, fills out sooner than the slow-growing cream-edged types. If you want a finished look fast, buy a larger pot size of a slow variety rather than expecting a small one to catch up.
Which Dwarf Pittosporum Handles Your Winter
A USDA hardiness zone is the map rating on plant tags for the coldest winter a plant can survive. MoJo is more cold tolerant than the standard species and is rated for zones 7 to 10.14Home & Garden Information Center. Pittosporum Wheeler’s Dwarf, by contrast, is widely grown in warm zones such as 9b to 10a in desert areas.15Three Timbers Landscape Materials. Dwarf Pittosporum Shrub Phoenix | Pittosporum tobira | Three Timbers Gardeners in zone 7 who want a cream-edged dwarf have the safest bet in MoJo.
Golf Ball’s species hardens off for winter. Leaves of Pittosporum tenuifolium become more frost resistant through autumn, surviving around 14 to 16°F by midwinter.16New Zealand Journal of Botany. The winter hardening and foliar frost resistance of some New Zealand species of Pittosporum The same plants are damaged near 27°F in summer, so an early or late frost hurts more than a midwinter one.17New Zealand Journal of Crop and Horticultural Science. Seasonal frost tolerance of some ornamental, indigenous New Zealand plant species in the genera Astelia, Dicksonia, Leptospermum, Metrosideros, Phormium, Pittosporum, and Sophora A frost in early fall catches leaves before they have hardened, and a late spring frost can hit after growth has softened again. Cultivars differ, too: one tenuifolium variety was damaged at 23°F while another survived to 16°F before damage.18New Zealand Journal of Crop and Horticultural Science. Seasonal frost tolerance of some ornamental, indigenous New Zealand plant species in the genera Astelia, Dicksonia, Leptospermum, Metrosideros, Phormium, Pittosporum, and Sophora
Look up your zone by ZIP code on the USDA map, then compare it with the zone range for the variety you want. A zone rating is a minimum for typical winters, so a plant at the very edge of its range can be hurt by an unusually cold year.
At the edge of a variety’s range, plant in a spot sheltered from cold winds, such as near a south wall. Avoid late-season fertilizing that pushes tender growth before frost, and cover young plants with frost cloth during sudden cold snaps in fall or spring.
If you want a Golf Ball in a cold-winter yard, ask the nursery which tenuifolium selection it is and whether it has been grown locally. A plant that has survived a few winters in nearby gardens is better evidence than a tag alone.
Tobira types handle summer heat well. During an extreme urban heatwave, Japanese pittosporum showed the least crown damage among the trees and shrubs compared.19Climate. Tree Crown Damage and Physiological Responses Under Extreme Heatwave in Heterogeneous Urban Habitat of Central China
Sun, Shade and Coastal Conditions
Light needs depend on how hot your summers are. Wheeler’s Dwarf suits north-side foundation plantings in warm climates where shade is a challenge.20T-Y Nursery. Keep it Low: Dwarf Shrubs for Tight Spaces In cooler zones it does better in sunnier spots.21T-Y Nursery. Keep it Low: Dwarf Shrubs for Tight Spaces
To read your site, watch the bed for a full day and count hours of direct sun. In a hot-summer region, a spot with morning sun and afternoon shade is usually the easiest on the leaves, since afternoon sun stresses them more than morning sun. Cream-edged types in intense afternoon sun can show leaf scorch on the pale edges. In a cooler region, the same shrub in deep shade may grow thin and slowly, so give it as much sun as the spot allows. Cream-edged leaves may also lose contrast in deep shade.
These shrubs are excellent near the beach. Wheeler’s Dwarf and variegated Japanese pittosporum are rated highly tolerant of salt spray, salty soil and strong wind.22College of Tropical Agriculture and Human Resources (CTAHR), University of Hawaii at Manoa. Salt and Wind Tolerance of Landscape Plants They can go in exposed spots facing direct ocean winds.
Even tolerant plants benefit from an occasional deep watering that flushes salt down through the soil, below the reach of the roots. Tolerance describes the leaves, but the soil must still drain well, and sandy coastal soils usually do. Wind also dries leaves, so a newly planted shrub in an exposed spot needs more frequent watering until it establishes.
Soil and Drainage Make or Break These Shrubs
Pittosporum grows in acidic or alkaline soil and in sand, loam or clay.23Home & Garden Information Center. Pittosporum The one condition is drainage: the soil must be well drained, because excess moisture can kill it quickly through root rot.24Home & Garden Information Center. Pittosporum For that reason, Wheeler’s Dwarf should not go right against a foundation where drainage is poor.25EDIS. Pittosporum tobira ‘Wheeleri’: Wheeler’s Dwarf Pittosporum Its roots usually do not cause problems for nearby paving or structures.26EDIS. Pittosporum tobira ‘Wheeleri’: Wheeler’s Dwarf Pittosporum
Foundation beds are risky because roof runoff and gutter overflow often collect along walls, and builder’s fill near foundations can be compacted and slow to drain. Set plants a couple of feet out from the wall, where soil drains better.
Test drainage before planting. Dig a hole about a foot deep and fill it with water. If water still stands after several hours, drainage is too slow. In heavy clay, keep downspouts and sprinklers from soaking the root zone.
In clay, planting the root ball a little high, on a gentle mound, lets water run away from the crown. Mixing a small amount of compost into the surrounding soil is fine, but filling a hole with rich soil in clay can create a bowl that collects water. Break up the sides of the hole so roots can grow out into native soil instead of circling inside the amended area.
Spots where puddles linger a day after rain, or where moss and mud persist, are poor places for these shrubs. Sandy soil drains fast, so no special preparation is needed there, only regular watering while the plants are young.
In containers, any pot needs holes in the bottom, because a pot without drainage becomes a bowl of standing water. Don’t let a container sit in a saucer of water for long periods, and use a standard potting mix that drains freely rather than garden soil, which packs down in pots.
Planting and Watering Your First Year
Pittosporum is drought tolerant once established but looks healthiest with regular water, especially early on.27Home & Garden Information Center. Pittosporum Variegated pittosporum watered every 2 days grew more leaves and a larger canopy.28HortScience. Irrigation Affects Landscape Establishment of Burford Holly, Pittosporum, and Sweet Viburnum Watering less often still allowed it to establish without extra stress.29HortScience. Irrigation Affects Landscape Establishment of Burford Holly, Pittosporum, and Sweet Viburnum
To plant, dig a hole as deep as the root ball and twice as wide. Set the top of the root ball level with or slightly above the soil, then water deeply right away. Mulch a couple of inches deep, keeping it off the stems.
Water by feel instead of by calendar. Push a finger into the soil and water only if the top inch or two is dry, because rain, temperature and soil type change how fast it dries. In the first weeks, the soil should stay slightly moist but never soggy. Water at the base, slowly, so it soaks down rather than running off.
After the first growing season, cut back. Once roots have spread into surrounding soil, the plant can go longer between waterings, and a deep, occasional soak encourages deeper roots than frequent light sprinkling. In prolonged hot, dry spells, even established shrubs look better with an occasional deep watering.
Common Problems and What to Do
Dwarf pittosporum is quite susceptible to root rot when soil stays wet for long periods.30LSU AgCenter. Pittosporum Problems As one section of roots dies, the matching section of the shrub wilts and dies.31LSU AgCenter. Pittosporum Problems
That pattern separates root rot from drought. Drought wilts the whole plant evenly and it recovers after watering. Root rot kills one side or section while the soil is still damp. Dig gently: healthy roots are firm and pale, rotted roots dark and mushy. Rotted plants rarely recover, so replant in a better-drained spot.
Cercospora leaf spot shows as small angular yellow to brown spots, mostly on older leaves, that can merge and cause leaf drop.32Texas Plant Disease Handbook. Popular Dwarf Pittosporum Varieties for Your Landscape A few spots on a healthy plant are mostly cosmetic. If spotting spreads, protective fungicide sprays give the best control. Start them before new infection rather than after, since a spray protects healthy leaves and does not repair spotted ones, and follow the label for timing and rate. Watering at the base instead of overhead keeps leaves dry, which discourages leaf spot, and removing fallen spotted leaves keeps them from remaining a source of infection.
Mealybugs and spider mites can infest pittosporum.33Gardening Know How. Gardening Know How Mealybugs look like white cottony tufts along stems and leaf joints, while spider mites leave fine speckling and webbing under leaves. Neem oil is a common, low-toxicity treatment for both.34Gardening Know How. Gardening Know How Spray in cool evening hours to avoid leaf burn.
Pruning and Shaping
Wheeler’s Dwarf rarely needs pruning to stay tidy.35Three Timbers Landscape Materials. Dwarf Pittosporum Shrub Phoenix | Pittosporum tobira | Three Timbers Golf Ball keeps its round shape with little or no trimming.36Jackson’s Nurseries. Popular Dwarf Pittosporum Varieties for Your Landscape37Plantmark. Pittosporum tenuifolium Golf Ball
When you do prune, trim lightly right after spring flowering, which keeps next year’s fragrant blooms and gives new growth time to harden before winter. Avoid heavy pruning in late fall, since the new growth it triggers is tender and easily hurt by frost. Thin crowded interiors to improve airflow and reduce leaf spot, and avoid shearing hard into old bare wood.
Remove dead or rot-damaged sections promptly, cutting back to healthy wood, which looks green or pale inside when you scratch the bark. Frost-damaged leaves can stay on until spring, and waiting to see where new growth starts shows how far back to cut. Clean pruners with rubbing alcohol between cuts when removing diseased parts so you don’t spread problems.