Rhododendron 'Weston's Pennsylvania'
Overview
Uses: Woodland edges, mixed shrub borders, pollinator plantings, partly shaded foundation beds, mass plantings under high canopy.
Benefits: Deep pink flowers with warm yellow throats that open in June and July, a full month after the azalea season is supposed to be over, carried on a robust upright frame bred for northern winters.
USDA Hardiness Zones: 4–8
Sun: Full Sun, Partial Sun/Shade
Life Cycle: Deciduous Shrub
Growth Habit: Upright, Spreading — open branching on strong straight stems.
Bloom Color: Deep Pink with Yellow throats
Mature Height: 5–6 feet
Mature Width: 4–5 feet
Bloom Season: Early to midsummer
Growth Rate: Moderate
Summary
By the time this azalea blooms, everyone has stopped looking at azaleas. That is precisely the point.
'Weston's Pennsylvania' belongs to the summer-blooming group developed at Weston Nurseries in Massachusetts, raised from a controlled cross between the native pinxterbloom azalea and two other named selections. The result flowers in June and July, weeks after the evergreen azaleas have finished and the spring border has moved on. The blooms are deep pink with warm yellow-orange throats, built on the elongated tube and starry outline of our native azaleas rather than the wide flat face of the Asian hybrids.
Individually the flowers are modest. The effect comes from quantity — the plant sets them in dense clusters across the whole canopy, and a mature specimen in full bloom reads as a solid mass of color from across a yard. Light fragrance is characteristic of the Weston summer group and adds to the effect at close range.
Structurally it is a strong upright grower with notably sturdy stems, reaching five to six feet with a slightly narrower spread. It was bred and selected in New England, which shows in its cold tolerance and its general willingness to perform without fuss in northern gardens.
The late bloom also puts nectar in front of pollinators at a point in the season when most woody plants have finished, which makes it more useful in a habitat planting than its spring-flowering relatives.
Care
Deciduous Azalea 'Weston's Pennsylvania' Care
Plant in full sun to partial shade. Deciduous azaleas take considerably more sun than evergreen types, and more light means heavier bloom. In hot climates, protection from direct afternoon sun keeps the foliage clean.
Soil must be acidic, organic, and well drained while staying evenly moist. Amend with composted bark or peat at planting and mulch with pine fines or shredded leaves. Alkaline soil produces yellowing and steady decline.
Keep the root zone consistently moist, especially during establishment and midsummer heat. The root system is fine and shallow and dries out faster than the plant's size suggests. Mulch is essential.
Feed lightly in early spring with an acid-forming slow release fertilizer. Avoid lime and avoid heavy applications — the fine roots burn easily.
Prune immediately after flowering. Buds for next season form on old wood during summer, so any later cutting removes bloom. Most plants need only the removal of dead or crossing stems. If you see a stem wilt suddenly in summer, cut it out below the damage and dispose of it, since stem borers are the one pest this group is prone to.
Size
What Size is the Deciduous Azalea 'Weston's Pennsylvania' for Sale Online?
Our Deciduous Azalea 'Weston's Pennsylvania' ships in a greenhouse-grade grow pot and is appropriately sized for its container at the time of shipment. If you have specific sizing or planting questions, please contact us.
How Large Does Deciduous Azalea 'Weston's Pennsylvania' Grow?
Expect roughly 5 to 6 feet tall and 4 to 5 feet wide at maturity, upright and slightly taller than broad. Growth is moderate. Space 4 to 5 feet apart for a connected planting, or give a single specimen room to show its full outline.
Additional Information
What are some common names for this plant?
This shrub is sold as Weston's Pennsylvania Azalea or simply Pennsylvania Azalea, and it belongs to the group generally marketed as Weston summer-blooming azaleas. It is a deciduous azalea, not an evergreen type.
Why does it bloom in summer instead of spring?
It was bred that way. The Weston summer-blooming hybrids were developed specifically to extend the azalea season past its normal close, and this one flowers in June and July rather than April and May. Its parentage traces to native azalea species that naturally bloom after they leaf out. More options are in our Azaleas collection.
How cold hardy is it?
It was bred and selected in Massachusetts and is reliably hardy through zone 4. The summer bloom timing carries a secondary benefit in cold regions — flower buds open well after any risk of late frost, so you do not lose a season's display to an April cold snap the way you can with early-blooming azaleas.
Is it native?
It is a nativar. The cross that produced it used the native pinxterbloom azalea, Rhododendron periclymenoides, along with other selections, so it is a bred hybrid rather than a wild species. It carries the flower form and late season of its native parentage. Straight species and other native selections are in our Native Plants of North America collection.
Will deer bother it?
Deciduous azaleas are browsed more readily than most shrubs, and new spring growth is the most vulnerable part. In areas with steady deer pressure, protect young plants for the first several seasons. Our deer-resistant shrubs and evergreens are a more dependable choice where browse is constant.
