Where there is a need for a climbing vine that clings to almost anything and tolerates shady conditions as well as sun, few plants are as suitable as Boston ivy. This is the same plant that gives Ivy League universities their nickname, from the lush greenery that climbs their storied walls. In some areas, Boston ivy also makes an easy-care ground cover plant.
This deciduous woody vine is remarkably easy to grow, but you will probably need to periodically prune it aggressively to keep it in check. Though not as problematic as English ivy, Boston ivy can damage wood siding, gutters, and even roofing if it is left unsupervised. In scattered parts of North America, it is regarded as an invasive plant, and growing it is discouraged. But where suitable, Boston ivy is always a better choice than English ivy.
Boston ivy vines not only lend greenery through the summer, but they also provide fall color. In spring, the new leaves of Boston ivy are reddish. The leaves typically turn green in summer before reverting to a reddish color in fall. The plants produce inconspicuous flowers, yielding to clusters of dark blue berries that birds enjoy.
Boston ivy is generally planted from potted nursery starts in late spring or early summer. It is a fast-growing vine that can add 3 to 10 feet each year. Mature plants can reach 50 feet and sometimes even more.
|Botanical Name||Parthenocissus tricuspidata|
|Common Name||Boston ivy|
|Plant Type||Perennial deciduous vine|
|Mature Size||30–50 feet|
|Sun Exposure||Full sun to part shade|
|Soil Type||Loamy, medium-moisture soil|
|Soil pH||5.0–7.5 (acidic to slightly alkaline)|
|Bloom Time||June to July|
|Flower Color||Greenish white (non-showy)|
|Hardiness Zones||4–8 (USDA)|
|Native Area||China and Japan|
|Toxicity||Moderately toxic to humans, toxic to animals|
Boston Ivy Care
Boston ivy is a true climber, attaching to masonry and wooden surfaces using holdfasts (aerial roots). Alternatively, you can let it spread out horizontally to function as a ground cover. If you don't want the ivy to grow up walls, plant it at least 15 feet from any structure. Growing Boston ivy plants up garden arbors, pergolas, and fences are all sound practices. You can grow them on a trellis, as well, especially if you need a privacy screen in summer for a specific area of the yard.
The vines are also grown up walls for that Ivy League look, as well as to shade the wall for energy efficiency. Give the roots enough room by planting them 1 foot from the wall, and allow 18 to 24 inches between plants when planting for wall coverage.
If you wish to allow Boston ivy to scale building walls, make sure you're truly at peace with the idea of it becoming a permanent fixture. Once this vine gets a toehold, it's difficult to remove it from walls—you can damage a wall attempting to tear off an entrenched Boston ivy. It's better to train the vine to grow on trellises and similar structures unless you are sure that you want it as permanent "siding" on your walls.
Don't allow Boston ivy to climb a tree. The shade cast by the vine will interfere with a tree's photosynthesis, thereby depriving it of nutrients.
Grow these vines in partial shade to full sun. While it will tolerate full shade, Boston ivy needs full sun to achieve maximal fall color. In areas that have hotter summers, Boston ivy plants do best on walls facing east or north, where they get some shelter from the sun.
Boston ivy does best in well-drained, loamy soil, but it will tolerate many different soil conditions, as well as urban pollution.
Boston ivy has average water needs. During the first growing season, ensure it is deeply watered so the roots develop well. After that, water the ivy weekly, and more often when it is hot. The plant is fairly drought tolerant once it is well established.
Temperature and Humidity
Boston ivy generally does well in the temperatures common to its hardiness zone range—zones 4 to 8. Plants in exposed locations can sometimes be permanently damaged if winter temperatures fall below minus 10 degrees Fahrenheit. New growth can sometimes be damaged by late spring frosts, but the plant usually recovers quickly.
While fertilizing is often unnecessary, some growers apply a fertilizer high in phosphorus (the middle number in the NPK sequence) at planting time to encourage root development. An all-purpose fertilizer is fine for any later feeding you choose to do.
Boston Ivy Varieties
When you shop for Boston ivy at a garden center, you will often find named cultivars rather than the species plant. Consider these popular cultivars:
- 'Purpurea' and 'Atropurpurea' are similar, but the foliage of the former stays a more constant reddish-purple from spring to fall.
- 'Veitchii' starts out purple, is green in summer, then turns crimson in fall. It is marked by its smaller leaf size. By contrast, 'Green Showers' has leaves larger than those of most Boston ivy cultivars.
- 'Fenway Park' is an unusual cultivar with spring foliage that is yellow. The leaves change to green in summer, then to red in autumn.
Propagating Boston Ivy
To propagate Boston ivy, take cuttings in the spring from healthy-looking stems. Include about five to six nodes in the cutting. Remove all but two or three pairs of leaves. Apply rooting hormone and plant the cutting in a cactus mix or a blend of perlite and peat moss. Water from the bottom and transplant to a soil mixture once the roots have developed.
How to Grow Boston Ivy From Seed
Boston ivy can also be propagated from seeds collected from the berries. Harvest some berries when they are ripe and full, then crush them and carefully remove the seeds from the pulp. Wash and dry the seeds on paper towels. Store the seeds in a bag or container filled with some loose sand in the refrigerator for about two months, which will simulate the natural plant cycle. In early spring, plant the seeds in the desired location, about 1/2 inch deep, and keep well-watered until the plants sprout and become well established. You can also sow the seeds in small pots, then transplant them into the garden once they are several inches tall.
These plants are vigorous growers. Prune the vines once each year (in late winter or very early spring), to check the rapid growth. Simply prune away any growth that is out of place (either vines that are sticking out in an unsightly way or those that have grown beyond acceptable territory). The vines respond well to pruning, so have no fear of damaging them.
As you might expect from a plant with a reputation for aggressive, sometimes invasive, growth, Boston ivy is not often affected by serious problems. But they are sometimes plagued with scale, which can cause plants to turn yellow, then lose their leaves in spring or summer. If this occurs, carefully inspect the vine stems for the small scabby lumps that indicate scale insects. Large infestations can be treated with a spray mixture of one tablespoon of alcohol mixed with a pint of insecticidal soap.
Another common problem is powdery mildew, which creates a powdery white residue on the leaves. This rarely kills the plant, but if necessary it can be treated with a sulfur spray in two applications, spaced two weeks apart.
Boston Ivy vs. Virginia Creeper vs. English Ivy
Boston ivy is often confused with two other common climbing plants. One is a close relative, Virginia creeper (Parthenocissus quinquefolia). For identification purposes, note that Virginia creeper's leaf is a compound leaf, composed of five leaflets. Boston ivy's leaf may be compound on young plants but once mature, it bears a simple, not a compound leaf.
Boston ivy is also sometimes confused with English ivy (Hedera helix) by beginning gardeners, but the two plants are not related. English ivy is evergreen, while Boston ivy is not. Autumn foliage on English ivy remains a dark green; it does not turn red, as does Boston ivy. English ivy is also a considerably more aggressive plant that can grow to 100 feet or more. Many areas of North America regard English ivy as seriously invasive.