Dan Songster, former president of the Orange County Chapter of the California Native Plant Society (OCCNPS) submitted this article featuring ‘Howard McMinn’ manzanita as the featured plant of the month for July.

• What: Arctostaphylos ‘Howard McMinn’
• Type: Evergreen Shrub
• Light: Full sun to light shade
• Soil: Likes good drainage but more adaptable than many manzanitas
• Water: Occasional
• Common Habitat: Chaparral
• Family: Ericaceae (Heath Family)

The Basics

Arctostaphylos ‘Howard McMinn’ is perhaps the best known of California’s many manzanita species and due to its relative ease of growth, sometimes referred to as “everyman’s manzanita.”

First introduced by the Saratoga Horticultural Foundation in 1955 from plants given to them by Howard McMinn, native plant author and Mills College botany professor. It was originally described as a low shrub, growing to five feet tall, but in the half century since its introduction, we have learned that this plant can reach twice this height and much wider. After all these years, it is still one of our the most widely recommended and planted native shrubs. 

‘Howard McMinn’ manzanita is a member of the Heath family, with the same clusters of small, bell-shaped flowers that bloom white to light pink, similar to most of the flowers in the Heath family.

Manzanitas bloom in late winter/early spring and ‘Howard McMinn’ is no exception–in fact it blooms later and longer than many other manzanitas, extending the bloom time sometimes into late spring. The lovely flowers are followed by clusters of small fruits. With its fine-textured bright green foliage and smooth burgundy ornamental bark, it is a handsome plant even when not in flower.

Since it is easy to grow (for a manzanita), this is a good plant to try even if you know little about native plants but would really like to have one of California’s most iconic shrubs in your landscape! 

Garden Uses 

Use ‘Howard McMinn’ as a specimen shrub in the front or backyard. With its sculptural trunk, it can be the centerpiece of any small landscape area. Lovely and a bit compact when young, as it matures it will open up and reveal more of its twisting red-colored branches like a beautiful piece of art.

Whether alone or in a staggered grouping, ‘Howard McMinn’ is pretty enough to hold its own in the most manicured of neighborhoods. In addition, its size is perfect for hiding an ugly block wall and it also makes a nice informal hedge between you and the neighbors. 

Anyone who plants this manzanita is in store for a treat, as Constance Vadheim mentions:

“Gardeners often choose manzanitas for their evergreen leaves and red-brown bark. This cultivar displays both from an early age. In fact, from a foliage standpoint, ‘Howard McMinn’ has to be one of the prettiest manzanitas available.” 

Due to its ability to accept more ill-timed water than other manzanitas, some believe ‘Howard McMinn’ is an excellent native to use when trying to transition from a watered flower bed to a drought tolerant area.

Planting

If you have loamy sandy soils, ignore this section. But if you have very heavy soils, like the clay many of our Orange County homes are built upon, my best advice regarding planting manzanitas is to alter the soil with a small mound. Normally, I advise to try and plant what will grow in your existing soil rather than altering it, but manzanitas are a special case and I will do what I can to make them successful despite my clay soils. 

You have probably read about planting on a mound, but what does that really mean? It does NOT mean a huge hill created with tractors, nor does it mean simply building a clay soil hill on the clay soil you already have. Adding clay soil may help water on the soil surface run away from the plant stem or small trunk, but it does very little to aid drainage within the soil structure itself.

Since the main purpose of this effort is to create a root zone more compatible with a manzanita’s needs, my personal experience has been to first roughly break up the top layer of clay soil and then add a mix of decomposed granite, pumice, and even gypsum, mixed with some of your native soil. Just raising the soil level by 14-18 inches with this better draining mix can make a difference in your sensitive manzanita’s root crown being above the heavier clay soils that tend to get wet and stay wet, which is a favorite home for dangerous fungal pathogens that cause various root rots. The improved soil matrix with various sizes of ‘air pockets’ could mean the difference between a plant that lasts just a year or two and fades, or one the thrives for a decade or more. 

Care

Arctostaphylos in general are prone to disease when watered during the summer months. Although ‘Howard McMinn’ is less sensitive and more garden tolerant than other manzanitas, for greatest success, plant them in the fall or early winter to get established before summer arrives. Bert Wilson of Las Pilitas Nursery stated, “We have noticed that the only things these shrubs won’t put up with are hard pruning cutbacks or overly wet soil in the summer for an extended period. Other than that, they are an ideal plant to grow!”

Constance Vadheim is again on point with her advice:

“‘Howard McMinn’ is more forgiving than most manzanitas when it comes to garden conditions.  It can take full sun near the coast, but does better with some afternoon shade in most local gardens. It loves well-drained sandy soils, but does fine in clay loams and clays (especially if planted on a low berm). Quite drought tolerant once established, ‘Howard McMinn’ is more tolerant than most manzanitas of a little summer water.  But don’t over-water – once a month should be plenty.”

This susceptibility to various root rot pathogens usually occurs in the hottest months when there is a tendency to overwater. Watering deep and infrequently during the cooler months is essential to the health of this plant. Besides providing the needed water for leaf growth and photosynthesis, it also aids the manzanita in developing a good root system that can help it through those stressful summer months. Once the plant has matured, you can allow the soil to dry out in the summer.

Minimal pruning work is needed — mostly to remove dead/diseased wood, to maintain shape, or to reveal its interesting and colorful branch structure. Pruning is best done in late winter or early spring before new growth starts. 

The first time I saw this plant in cultivation was decades ago at Stanford University, where it was used as a hedge plant in some of the hottest, most exposed areas of campus–even as median plant in the parking lots! I’m not sure how long these plants survived but they were sheared with gas-powered machines routinely. I would think lighter more thoughtful work would be better. I recommend pruning it into an attractive little tree or kept rather low (4-6 feet) and densely green with regular tip pruning.

Note: ‘Howard McMinn’ responds well to light pruning, but flowers will only be produced on new growth, so regular tip pruning may result in fewer or no flowers! 

As with many other natives, it can be a good idea to use mulch to help retain soil moisture, reduce weeds, and protect roots, but be sure to keep mulch away from the stem.

Pollinators

Adding interest to your garden are the pollinators this plant attracts, such as moths, hummingbirds, butterflies and all sorts of other native wildlife. A special feature of manzanitas is their “need” for buzz pollination. Bumblebees use a ‘sonic’ technique to extract pollen from manzanita’s bell-shaped flowers. By grasping the flower and hanging upside down with their belly facing upwards, they dislocate their wings but “turn on” their flying muscles. The vibration causes pollen to fall onto and stick to their furry tummies. Most manzanitas and their relatives rely on this type of pollination. If you see bumblebees in your garden, pull up a chair and watch them interact with your manzanita flowers–fun! 

Origins 

San Marcos Growers website notes: “This cultivar is often erroneously listed as a cultivar of the rare Vine Hill Manzanita (Arctostaphylos densiflora), which is a smaller, pink-flowering species with a very restricted natural range near Sebastopol in Sonoma County. Current thought is that this plant is definitely of hybrid origin and possibly a hybrid between Arctostaphylos stanfordiana and A. densiflora because these two species are found in this same Vine Hill area. But there is a good possibility that several other manzanita species such as Arctostaphylos bakeri and A. manzanita might also be involved in this hybrid.”

‘Howard McMinn’ was first introduced by the Saratoga Horticultural Foundation in 1955 from plants given to them by Howard McMinn, professor of botany at Mills College. McMinn had cultivated a group of Arctostaphylos seedlings on the Mills College campus in Oakland from seedlings he had received from nurseryman Louis Edmunds in the spring of 1949. He later suggested that the Saratoga Horticultural Foundation test these seedlings out. Besides the plant that was later named for McMinn, the cultivars ‘Sentinel’ and ‘Harmony’ were all introduced from these seedlings. ‘Howard McMinn’ manzanita became the most popular and later received the Award of Merit from the California Horticultural Society in 1956.

Do you have a ‘Howard McMinn’ manzanita growing in your garden? Write us back and share your experience with this lovely native plant. And just for fun, here is a poem by Thea Gavin, a native plant gardener, sharing about losing a ‘Howard McMinn’ manzanita in her garden. Even the most experienced gardeners make mistakes sometimes, but that doesn’t discourage them from trying again.

Manzanita Blues
by Thea Gavin

'Howard McMinn' died yesterday. I killed him.
He shivered, shrugged his leaves, and croaked,
not much more than a sprout,
not a 4-to‐6-foot garden focal point—
his handsome potential, according to the label.

How did it happen? Who knows? Maybe it was
circumstances beyond my control:
The economy. His own fault for not
taking better care. I did everything
I could. That's a lie. I could have read
up on manzanita just a little
before I summer-stuck him in the ground—
compacted foundation soil, south-facing
narrow strip that magnified the inland
August sun's relentless beaming.
(What was I thinking?)

It was an empty spot, and little Howard
had looked adorable in black one-gallon plastic.
I'm sorry, Howard. I'll do better next time:
maybe haul in some D.G. and make a crumbly
pillow-mound where drainage would delight
your delicate roots, above the cloying clay . . .

And thus well‐drained, my handsome Howard II,
would you reward me with a pale-pink flower
cloud sure to attract butterflies, some peely
purplish bark on a sculptured trunk,
graceful twisting arms aglow
with lime-green leaves and tiny apple fruits?
Howard II, I hear you calling. Wait
till autumn; I will meet you at the nursery.