(pay-OHN-ee-uh  ROK-ee-eye)

General Information:

Paeonia rockii is a lovely tree peony that should be grown more. It can be difficult to find in a nursery, but those specializing in peonies will have it. The ones pictured here were grown from seed obtained from our Seedex program. The flowers are mostly white or light pink with dark maroon basal flares on the petals. There is some variation in flower form and coloration. One seedling from this group has red leaves in early summer.

Paeonia rockii:photo by Robert Pavlis

The common name, tree peony, describes the woody stems that are produced, but it is probably more correct to call these shrubs, not trees.  They do not need staking.

Growing peonies from seed is very rewarding but does take some patience. It can easily take 5 years for Rock’s peony to flower, but it is worth the wait. Tree peonies can also be propagated by grafting a tree peony bud onto an herbaceous peony root. This is how most tree peonies are produced for the trade. Grafted plants may sprout new shoots from the herbaceous root and these need to be removed as soon as they are spotted. The leaves of tree peonies and herbaceous peonies look quite different once they grow next to each other.

Paeonia rockii, white form:photo by Robert Pavlis

In zone 5, tree peonies seem to have some die back each year. Wait until new buds are expanding and then remove dead tips off branches.

Click this link to find out more about germinating peony seeds.

Paeonia rockii, pink form:photo by Robert Pavlis

Life Cycle: shrub

Height: 180cm (6 ft)

Bloom Time: spring

Natural Range: China

Habitat: deciduous forests, forest margins, shady slopes, limestone rocks, 1100-2800 m

Synonyms:  Paeonia suffruticosa subsp rockii, Paeonia linyanshanii

Cultivation:

Light: part shade to shade, can take full sun in colder regions

Soil: well drained, humusy

Water: average

USDA Hardiness Zone: 4 – 9 (survives in colder zones but will die back to ground)

Propagation: seed, grafting

Seedex availability (ORG&HPS annual Seed Exchange): frequently

 (pak-ih-SAN-druh  pro-KUM-benz)

General Information:

It is difficult to find plants for dry shade but Pachysandra procumbens will be quite happy in such conditions, at least in cooler climates. In warm areas you might need to provide more moisture.

Pachysandra procumbens:photo by Robert Pavlis

If you are thinking to yourself that you know Pachysandra and that this is an invasive Asian species that should not be planted, you would be wrong. You are thinking of Pachysandra terminalis which is very popular as a ground cover because it covers everything. Pachysandra procumbens is quite different. It is a North American native, which will slowly cover the ground. Besides being better behaved, it also flowers nicely in early spring. This is a great woodland plant and should be grown much more.

It goes by the common names Alleghany spurge and mountain spurge referencing its native habitats. It can grow in full sun in cooler climates, but does much better in part shade or even heavy shade. It spreads slowly forming a tight cover that easily keeps out the weeds.

Alleghany spurge is an evergreen in zone 5 and warmer, but in cold climates the leaves do look ratty in spring. You can remove them before it flowers, but I never bother. New spring leaves will quickly cover the old ones. In my garden this is a no maintenance plant.

Pachysandraprocumbens:photo by Robert Pavlis

The color of the leaves depend very much on the amount of light it gets and the season. Too much produces light green leaves. In heavy shade the leaves are a much darker blue-green. In spring the leaves still show some silver mottling from the previous year. As summer progresses the leaves lose the silver color and become solid green. In fall the leaves turn a reddish color and the silver returns.

Life Cycle: perennial

Height: 20cm (8 in)

Bloom Time: spring

Natural Range: Southeastern United States and Texas

Habitat: rich soil with a limestone substrate

Synonyms:  none

Cultivation:

Light: part to full shade

Soil: adaptable

Water: drought tolerant in colder regions

USDA Hardiness Zone: 4 - 9

Propagation: seed, cuttings, division (seed is not used much)

Seedex availability (ORG&HPS annual Seed Exchange): rarely

 (or-RI-ga-num)

General Information:

Origanum ‘Kent Beauty’ is a wonderful little plant for the rock garden. It is not a show stopper, nor does it have big flashy flowers, but it does have a very unique look that gets people talking. It requires almost no care and has few pests.

Origanum ‘Kent Beauty’:photo by Robert Pavlis

Origanum ‘Kent Beauty’ is commonly misnamed Origanum rotundifolium ‘Kent Beauty’. It is actually a primary hybrid between O. rotundifolium and O. scabrum.

I have grown a few different origanums but none have really impressed me until I started growing this one. Each stem is about 15 cm (6”) long and pendent. Stems originating from the center lie on top of the stems growing towards the outer edge, forming a semi-mounding dome. It looks its best in a container, or growing over a rock so the pendent stems can drupe down.

Origanum ‘Kent Beauty’:photo by Robert Pavlis

The flowers are small but show up well through the large bracts which last all summer and cover the stems to such an extent that by late summer you hardly see the leaves. Flowers continue to develop all summer long. The Royal Horticultural Society has rightly given it the Award of Garden Merit.

The pictured plant was grown from seed obtained through the ORG&HPS Seed Exchange Program and is now about 5 years old. It is slow growing, but the mound gets bigger each year.

Oregano, Origanum vulgar, is closely related to this plant and is also in the mint family. Don’t let the reference to mint scare you off.  Kent Beauty does not spread like other mints. It does not make runners and has yet to make a seedling for me. Origanum ‘Kent Beauty’ can be eaten, but is more commonly used as an ornamental. Some people do collect the fragrant stems to make potpourri.

Once new growth starts in spring, cut last year’s growth back to a new bud. It requires no other maintenance for the rest of the year.

Origanum ‘Kent Beauty’:photo by Robert Pavlis

Life Cycle: perennial, considered by some to be a sub-shrub

Height: 15cm (6in)

Bloom Time: all summer

Natural Range: N/A

Habitat: N/A

Synonyms:  N/A

Cultivation:

Light: full sun

Soil: well drained

Water: drought tolerant once established

USDA Hardiness Zone: (5)6– 10, seems hardy in my zone 5 garden

Propagation: seed, division, basal cuttings in spring

Seedex availability (ORG&HPS annual Seed Exchange): occasionally