Uprooting Plants

Recently, as I was digging up four boxwood shrubs, and cutting down a twelve-foot elderberry, I recalled that some gardeners dislike toppling mature plants or discarding healthy ones.

This is not about relocating plants. Certainly, there are situations in which a plant has outgrown its spot, or has failed to thrive because of a lack of sun or moisture or nutrition, or simply doesn’t look right where it is, aesthetically.

In such situations, assuming the plant is not too big to move, go ahead and transplant to a better location within your garden, or gift it to a friend. You and the plant and perhaps your friend will be happier.

We might ask, “When is it a good idea to decommission a plant?”

One justification would be that the plant is both unwanted (for any of several reasons) and too big to move without significant effort or expense.

Another justification arises when an unwanted plant is not too big to move, but no alternative location is available in your garden or in the garden of any friend.

The option that remains is to lift the plant with care and bring it to a garden exchange. These events are constructive and popular when someone steps up to the task of organization.

One should link to the local gardening network to learn when and where a garden exchange will happen. Join a club!

An important mindset when removing a plant is to avoid any sense of loss, and instead to recognize the opportunity to bring in a new and more interesting plant. Therefore, one should have (1) a replacement plant already in mind, (2) the confidence and knowledge to grow the replacement plant, and (3) the patience to let the plant to reach full maturity.

The four boxwoods (Buxus sempervirens) I dug up had been intended to frame a rose bed, but these common plants had grown large enough to block the view of the roses. I will replace them with miniature roses, to be selected.

The elderberry was an unknown species, a gift that I planted before I realized how big it would get, and before I decided to devote that section of the garden to California native plants. A Pacific Red Elderberry (Sambucus racemosa) might have stayed, but this shrub’s berries were not red, but black.

I will replace this shrub with a Silverleaf Manzanita (Arctostaphylus silvicola), a beautiful very gray, and very endangered shrub that is endemic to the nearby Zayante Sandhills. It is also called the Santa Cruz Manzanita. I found a specimen at the Yerba Buena Nursery in Half Moon Bay.  It’s in a one-gallon nursery pot, so it will need time to reach its mature height of eight feet.

Uprooting plants can release space for new botanical treasures.

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Here’s a picture of the Silverleaf Manzanita, from the website of Las Pilitas Nurseries, a treasure trove of information on California native plants, as well as a great source of those plants. There are two locations: Santa Margarita (about 18 miles north of San Luis Obispo) and Escondido.

Arctostaphylos silvicola, Ghostly Manzanita with a beefly. This manzanita is native north of Santa Cruz.

 

Pruning Roses

There’s no need to rush outside to prune your roses, but now would be a good time to prepare for that annual process.

Start by identifying which of your roses are Old Garden Roses, and which are modern roses. The OGRs are once-bloomers, growing on their own roots, while modern roses, e.g., hybrid tea roses, are repeat bloomers, grafted on sturdy rootstock (often ‘Dr. Huey’).

There are numerous rose species, varieties and hybrids, but pruning methods differ greatly between the two broad groups: OGRs and modern roses. Briefly, OGRs bloom on old wood and are pruned in the late summer, after their bloom period and before they set buds. Generally, prune OGRs in a limited manner, removing no more than one-third of the bush.

In comparison, modern roses bloom on new wood, and are pruned more extensively during the winter months, before new stem growth and buds appear in the spring.

Modern roses are hybrids, typically with species that evolved in Asia, where winters are not harsh, so dormancy is related more to winter’s shorter days than to its lower temperatures. In the Monterey Bay area’s moderate climate, modern roses can continue to grow through the winter months without a period of deep dormancy.

Still, even a relatively light dormancy gives modern roses an important rest period, and pruning during this period promotes new stems and large blossoms.

This year, despite December’s record-setting warm spells, we can rely on short winter days to enable our roses to enter dormancy. Defoliation (stripping a rose’s leaves) encourages that process and reduces the potential for continued top growth.

With that background, prepare to prune your modern roses at any time during January or February. The basic techniques have been described and illustrated many times in books and websites, so rather than providing a capsule version of those techniques, I have listed print and online resources on my website, ongardening.com, for your reference.

I will repeat my recent suggestion to relocate your roses, as needed, during the same period. Prepare the new location by digging a hole two to three times as wide as the root ball you expect to have, to support horizontal root growth. The new hole should be only as deep as the existing root ball, to minimize settling of the transplanted rose.

We ready to transplant the rose soak the new location thoroughly. Then, soak the existing rose, lift a good-sized root ball from the bed, and plant it in its new location at the same level as it was in its old location. Water it in.

Now is also the time to select bare-root roses for your garden, so next week I’ll review rose selection and buying.

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There are many websites with good, free information about pruning roses. Search for “pruning roses” to see several options. Here are some that I found helpful:

All-American Rose Selections

David Austin Roses

American Rose Society (scroll down to the articles on “Pruning Roses”)

If you would prefer a book, look for these more general pruning titles in your local library or bookstore:

Pruning Made Easy – How to Prune Rose Trees, Fruit Trees and Ornamental Trees and Shrubs, by H.H. Thomas (2013)

This book will be published early in February 2014:

Pruning Made Easy – The Complete Practical Guide to Pruning Roses, Climbers, Hedges and Fruit Trees, Shown in Over 370 Photographs, by P. McHoy

More Seasonal Projects

Once we begin to list gardening projects for the fall, ideas keep coming.

As always, it is appropriate to pursue priorities only when the weather is inviting, and to work at a pace that supports your enjoyment of gardening. Seasonal projects can add to spring’s reawakening and the garden’s long-term success, but the plants will survive a little neglect, truth be told.

Prune Fruit Trees

If you are fortunate enough to have one or several apple trees, or other fruit trees, in your garden, they are likely to enter their dormant stage in December. During their dormancy, they should be pruned to produce a variety of benefits. The best practices depend on the kind of tree, its age, whether or not it has been neglected, and the specific reasons for pruning. That’s too many variables for this column, but well worth the tree owner’s research. An excellent source of information is The California Backyard Orchard, a website maintained by the University of California, Davis.

While visiting that website for pruning advice, check out the entry on Pests & Diseases as well. After pruning, seasonal spraying will discourage or eliminate pest and disease problems during the growing season.

The University of California always recommends organic methods, of course.

Sow Wildflower Seeds

This couldn’t be simpler…if it weren’t for the birds. But they can be outsmarted.

Purchase wildflower seeds at your favorite local garden center, or from one of mail order nurseries that specialize in California wildflowers.

  • There are hundreds of California native wildflowers, but retailers will stock popular varieties, e.g., Arroyo Lupine, California poppy, five-spot, baby-blue-eyes, perennial flax, Chinese houses, gilia, bird’s eyes, California bluebell, satin flower, godetia, fiddleneck, tidy tips, beach evening primrose. Any combination of these would provide a pleasing display.

The California poppy, our state flower, is a popular and attractive choice, but be aware that it self-seeds freely and can become a nuisance in the garden.

If you have limited space in your garden, consider planting a swath of wildflowers, to simulate a natural growth pattern. Clear the area of mulch and any weeds, and broadcast the seeds in an informal pattern (not in rows!). Rake the area lightly to make the seeds less visible to our beloved birds, and keep them moist with light watering until the rains begin.

If you have a larger area to seed, you have the opportunity to create a wildflower meadow that will self-seed in future years. The method is essentially same, except on a larger scale.

Another timely task in this season is weeding. We’ll explore that need later.

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We didn’t include any tasks with roses among November’s gardening priorities, because in this part of the year, in the Monterey Bay area, many roses are still growing actively, and even producing blossoms.

Here’s advice from All-American Rose Selections:

“It’s time to do nothing in the rose garden. Well, practically nothing, anyway. We have seen the breathtaking first big, beautiful blooms of summer. And now we marvel at the smaller, but perfect last roses of summer. Enjoy. Roll up the hose. Put away the pruners.”

One rose-related project to pursue without pruning would be prepare to transplant a rose that would do better in another location. (There is at least one such rose in my garden, which is struggling in the shade of an ever-larger Cotoneaster shrub.)

The preparation involves digging a hole in the new location. Dig a hole two to three times as wide as the root ball you expect to have, but only as deep. This will support horizontal root growth without risking excessive settling of the transplanted rose.

Then, wait until January or February, when the rose becomes completely dormant. Soak the new location thoroughly. Then, soak the rose, lift a good-sized root ball from the bed, and plant it in its new location. Water it in.

Dormant Season Only for Plants

Some might regard November as the beginning of the dormant season, with little or nothing for gardeners to do until spring. Not true!

Beginning now, we can pursue selected gardening projects will pay off later in the year. Still, the garden does not demand intensive work and daily dedication by the gardener during this season. It’s quite all right to take time off to celebrate the holidays, avoid nasty weather, and otherwise enjoy life’s many pleasures out of the garden.

There are many good gardening projects to do now in the garden; let’s consider three projects that are worth attention during November.

Plant Cool-season Ornamentals and Edibles

Visit your local nursery for cool-season flowers, e.g., pansies, calendula, candytuft, foxgloves, snapdragons, stock, sweet peas, and sweet alyssum.

Plant seedlings of cool season vegetable such as broccoli, carrots, cauliflower, chard, lettuces and greens, cabbage, potatoes, radishes, peas, bunching onions, and spinach.

Look for six-packs of seedlings at garden centers or farmer’s markets.

Plant Pacific Coast Irises

Several beardless iris species are native to the Pacific coast. Because they cross with each other freely, they are often referred to either as PCIs or Pacific Coast Hybrids (PCHs). Most common locally is the Douglas Iris (I. Douglasiana), named for David Douglas (1799-1834), who was the first botanist to describe this plant as it grew in the Monterey Bay area.

PCIs can be grown from seed, but more often from divisions. After listing a mature PCI clump, pull the stalks apart and store them in water for a few days as they develop white roots at least a half-inch long. Then, plant the divisions and keep them moist until four new leaves appear. Seasonal rains could be sufficient to establish the divisions.

Move Perennials and Shrubs

Plants vary in their ability to tolerate relocation. Roses and hydrangeas, for example, adapt quickly and easily to being moved, although they appreciate careful handling: lifted without being damaged, moved to a hospitable location (full sun for roses; morning sun and afternoon shade for hydrangeas), and watered in.

Generally, it is easy to move plants that tolerate rejuvenation pruning, e.g., abelia, dogwood, honeysuckle, hydrangea, lilac, mallow, penstemon, rose, Rose-of-Sharon, salvia, spirea and many others.

Shrubs with fine root systems, e.g., azaleas and rhododendrons, do not respond well to being moved.

For information on specific plants, search the Internet using the plant’s common or botanical name. Visit ongardening.com for successful search methods.

At this time of the year, plants are dormant, but not gardeners!

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The Yerba Buena Nursery website has a helpful pruning calendar for California native plants.

The National Gardening Association has brief but solid advice on dividing perennials.

SF Gate has suggestions for adding edible perennials to your garden. Right now is a good time. Some recommended plants might be unfamiliar: tree kale, yacon, ground cherries, chayote and banana passionfruit (Passiflora mollissima). Still, they might be turn out to be welcome new “friends.”

Master Gardener Marie Iannotti, writing on Ask.com, offers a good overview of pruning for several categories of garden plants.

To find information about specific plants in your garden, start by learning their botanical names. (Search ongardening.com for more information on botanical names.)

Then, using Google or another search engine search for the botanical name of the plant, plus “cultivate” or a more specific verb representing want you want to know. Include the variety name, when you know it. Examples:

Rosa minutifolia transplant

Hydrangea paniculata divide

Salvia greggii ‘Heatwave Glimmer’ prune

 

California Native Roses

Rosa Californica is the only rose in my garden that is native to California. It’s a fine plant, but tends to expand its territory through underground suckers.

When I came upon a healthy specimen of another rose identified as a California native, I grabbed it for my garden and worked to learn more about it and other California native roses.

I soon discovered that my new rose, R. multiflora, is an imposter! It is a native to Japan that has become naturalized in California and much of the U.S. In eastern North America, it is considered an invasive species, and even a “noxious weed” in grazing areas. Although it has many blossoms, it is most appreciated by goats.

Roses that are truly native to California typically have single pink flowers, varying degrees of fragrance, and spiny branches. They often are found near water sources. While they tolerate some drought and shade they grow best with ample moisture and sunlight. They can spread vigorously in hospitable circumstances, but are controllable with seasonal pruning.

Here are several species, in roughly north-to-south order.

  • California Rose (R. Californica). Grows in much of California in chaparral, riparian and central oak woodland plant communities. Most widely grown native rose. This photo  is from the website of the University of California, Santa Cruz Natural Reserves.
    Rosa_californica_California_Wild_RoseAs a side note, the UCSC Natural Reserves program includes five sites, including one in Marina and one in Big Creek (south of Carmel). The five sites ring the Monterey Bay along the National Marine Sanctuary that extends the entire coastline from the Golden Gate at San Francisco south to Big Sur, between 38 and 36 degrees North latitude along roughly 122 degrees West longitude.The wide range of habitats, from fog-enshrouded redwood forest to maritime chaparral, provide an unparalleled natural laboratory for marine and terrestrial research and serve as study sites for University scientists and students.
  • Ground Rose (R. spithamea). Native to central California from the San Luis Obispo area up into Mendocino and Humbolt and in the Sierras from Tulare to Yuba. Grows in chaparral and coastal sage scrub plant communities.
  • Nootka Rose (R. nutkana). Grows in riparian areas in northern California and up to Alaska.
  • Wood Rose (R. gymnocarpa). Grows from San Luis Obispo to northern California, and in other western states, and has large fragrant blossoms.
  • Whiskey Rose (R. pinetorum). A relatively rare rose that has been spotted in northern California and in the Monterey area. Resembles R. gymnocarpa.
  • Cluster Rose (R. pisocarpa). A fairly large plant, up to six feet high, with flowers in clusters near the top. Grows in northern California to British Columbia.
  • Mountain Rose (R. woodsii ultramontane). Grows in high elevations east of the Sierras, and produces large numbers of very fragrant dark pink blossoms.
  • Mojave Rose (R. woodsii glabrata). Grows near springs in the Mojave Desert. Similar to R. Californica.
  • Baja Rose (R. minutifolia). Grows in Baja and the southern section of San Diego. It has very small leaves and bright pink flowers with prominent yellow stamens.

The information in this column was drawn largely from Wikipedia and the website of Las Pilates Nursery, a great source of information about California native plants.

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This photo is from Suisun Marsh page of the California Department of Water Resources website. The photo shows Rosa Californica’s rampant growth and numerous rose hips. This plant can be controlled in a garden, through seasonal (and diligent) pruning.

0CCARosehips copy

Garden Priorities for Summer

Last week, regarding summer care of roses, I briefly recommended fertilizing monthly and responding promptly to signs of insect or disease problems. Those are constructive actions, but there’s more that can be done to help your roses to flourish!

Fertilizing roses in the summer is important if they show signs of nutrient deficiency, such as weak growth. Provide a light application of fertilizer with an emphasis on phosphorous.

Recall that fertilizer labels indicate the percentages of the three principal ingredients: N – nitrogen (promotes the growth of leaves and vegetation); P – phosphorus (promotes root and shoot growth); and K – potassium (promotes flowering and fruiting). I have used Dr. Earth’s Rose & Flower Fertilizer (5–7–2), but you could find other very good fertilizers at your local garden center. As always, follow supplier’s recommendations.

Yellowing foliage probably indicates an iron deficiency, which calls for spraying with a liquid iron supplement.

The most common pest of roses is the aphid, which suck the plants juices from buds, stems and the underside of leaves. They can be washed away with a forceful stream of water, or treated with a spray of insecticidal soap, such as Safer® Brand insect killing soap.

I routinely grow Society Garlic (Tulbaghia violacea), which has a garlicky fragrance that seems to confuse or distract aphids. It really works!

Weekly watering will keep roses healthy during the summer months. Water roses at ground level to keep foliage dry and avoid fungal diseases. Use organic mulch to minimize evaporation and discourage weeds.

Deadheading spent blossom will promote new blooms. Cut them off close to a close to a cluster of five leaves; some experts recommend cutting at the second five-leaf cluster, to encourage growth from a stronger stem.

Remove suckers at the base promptly. If possible, pull them off from the rootstock; otherwise, cut them below the soil surface.

***

Deadhead other spring-blooming plants. This practice improves the appearance of the garden, promotes new blossoms from many plants, and reduces the spread of seeds (which might or might not be desired).

Currently, I am deadheading two larger plants: Corsican Hellebore (Helleborus argutifolius) and Mediterranean Spurge (Euphorbia characias, subsp. wulfenii).

Here are Hellebores in full bloom, standing upright.

Hellebores-1 Hellebores-cu2

And here they are laying over:

DSC02465

Here are the Euphorbias, fading:

DSC02469 DSC02468

These plants are quite different but still have common characteristics: they both produce large, dense clusters of flowers on thick stalks that bend over as the flowers fade to drop seeds away from the base of the plant. Both also are prolific self-seeders, if allowed.

At the same time, they produce new growth that limits access to the base of the flower stems. I have found a telescoping pruner to be invaluable in this task. A “cut & hold” model would be ideal.

Enjoy your garden in the summer!

Late-season New Growth on Roses

At this time of the year, ordinarily, roses have entered dormancy. This status, characterized by stopped growth above ground, protects the rose from winter freezes and provides a rest period that supports the plant’s longevity and productivity. Hothouse roses subject to year-round harvesting of blossoms have shorter lives and fewer blossoms, compared to the typical garden rose.

During dormancy, the rose reduces its metabolism, holds its fluids and nutrients away from the stems and stores them the core of the plant. This is the rose’s defensive position, designed to avoid a possible freeze of liquids in the stems.

The plant continues to develop below ground: root growth continues during the winter months and is important for newly planted roses.

Gardeners in the world’s colder regions worry that an unusual warm spell in the late winter or early spring might cause their roses to “break dormancy.” The plants could produce new growth that would be killed by a late freeze.

In more temperate climates, such as the Monterey Bay area, roses could show new growth of leaves and buds in the early winter for the same reason: an unusual warm spell. The National Weather Service, reports that the Monterey Bay area is having such a warm spell this year: November’s average high temperature was about five degrees above the historical level. When the NWS reports December’s data, we might well see the same pattern.

In such cases, gardeners need to either let their roses develop such new growth, or proceed with seasonal pruning. Here are three issues.

First, the new growth might not survive the winter cold. If that happens, the plant will have wasted energy producing the new growth, but suffered no lasting harm. A rose has two inactive dormant buds at the base of each leaf that can activate to grow new canes or leaves.

Second, if the new growth survives, the rose will miss its opportunity to rejuvenate. This could have long-term negative effects on the rose’s life and blossom production.

Finally, a break from dormancy means that the plant is sending fluids into the stems, making it vulnerable to a freeze that would expand the fluids and cause splits and tissue damage.

The preferred response to a broken or delayed dormancy, then, is to help the rose to enter dormancy. The gardener can do this by removing all leaves from the plant. This action will halt photosynthesis and encourage dormancy.

Once the plant becomes dormant, the gardener could accomplish seasonal pruning during the dormant period, which will continue to the early spring, after the last date when frost is expected.

Scientists are virtually unanimous in agreement that human-produced carbon dioxide emissions are causing global climate warming. This change is having countless effects, and including new issues for gardeners.

Fortunately, roses are tougher than they appear.

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As part of my research into rose dormancy, I visited the website of the American Rose Society, which has great information on many aspects of rose growing. I didn’t see discussion of the late-season new growth growth issue, so I clicked on the link, “Ask a Question About Growing Roses,” and asked my questions.

I received a quick response from AIS Master Rosarian Karl Bapst, a self-described “Rosenut.” His own website http://www.rosenut.com/ has a wealth of rose-growing information that I expect to visit often in the future.

I even quoted Karl (without attribution!) for the closing line of my column.

Rather than trying to summarize his detailed information, I am including our e-mail dialog below, with minor editing.

KARWIN

Roses in this area (USDA Zone 9a) should be dormant now (mid-December). Some people have started winter pruning, only to discover that their roses have new leaves, due to an unusual warm spell (possibly global warming) in November. This new growth probably won’t survive the colder weather in January, but what harm might be done to the plant by pruning when new growth is showing? Also, what harm might cold weather cause to a rose with spring-like new growth in December?

BAPST

In your area, I doubt your winter temps will drop down far enough to damage any new growth. New growth has lots of sugar that acts as natural antifreeze. In my area, zone 5a, mid-spring temps can drop to the mid to low 20s and new spring growth is seldom affected. If it is affected, new growth occurs to replace it.  Keep in mind there are two inactive dormant buds at the base of each leaf. If that new leaf should die, one or both of the buds activate growing new canes or leaves. So, should any new growth be damaged by temps below the mid 20s, it’ll soon be replaced.

We often have new growth before we prune in spring. The rose bushes do just fine. I’ve pruned as late as late April and early May (due to inclement weather or illness) after the bushes are leafed out with no bad results. The roses even bloom at their normal times.

Roses are tougher than they appear.

KARWIN

I have sent in my column today with recommendations based on your advice, but I have a follow-up question. Last night, a Consulting Rosarian recommended responding to this new growth by defoliating the plant to encourage dormancy and completing seasonal pruning. (Most people around here prune between mid-December and mid-January.)

Comments?

BAPST

In warmer growing zones where there may not be natural dormancy, removing the leaves will promote a period of dormancy when the daylight shortens and temperatures moderate as we approach the winter solstice. Roses don’t naturally go dormant and will grow all year if conditions are right.

Modern roses bloom best on new wood, pruning promotes new wood so one gets more and bigger blooms. In my zone 5, winter’s cold and gloomy overcast skies, freeze and kill the leaves. Most stay on the bush until new growth or pruning removes them. The frozen soil and canes causes all growth to stop until conditions improve in late winter or early spring. Summer cutting of roses is pruning. You’ve noticed that cutting a bloom in summer causes a new cane to develop, usually from the base of the leaf under the cut. This occurs after your December/January pruning but on a larger scale.

Should you fail to prune or cut back then, any blooms produced on the un-pruned bush will normally be smaller and fewer on shorter canes. You’ll notice, though, any blooms will come from those short new growth canes. Even blooms that grow from the old cane tips will be on new growth.

In my area, we have no choice. When removing winter die-back or damaged canes, we force new cane growth. Often, especially on hybrid teas, which are naturally very winter-tender, removing die-back requires pruning almost to the ground. These bushes will bloom in late May/early June and will have grown to full size by July.

Understand, Old Garden Roses (OGRs, once-a-year blooming roses) bloom on old wood and buds are set the previous fall. Pruning on OGRs is done after they bloom or these buds would be removed when pruning. Should you get any questions from people asking why their roses don’t bloom it’s usually due to them pruning too early on Old Garden Roses.

KARWIN

I read a variety of online material in preparing this column, and found various pieces of relevant information.

For example, here’s an interesting point for the eHow.com website:

“Most rose plants that are capable of dormancy will not naturally initiate this process in response to cold weather. Most rose plants which are domestically grown in North America are hybrids with breeds of plants that evolved in Asia (most roses are Asian and are crossbred for their desirable characteristics, such as smell and appearance). Asian winters are not as harsh and, thus, dormancy in Asian roses is an evolved response to a lack of light. This can create problems for such roses in North America, where a cold winter can still supply enough sunlight to encourage the plant to keep growing.”

Such subtleties can be challenging for a garden writer with a deadline, and impossible to explore in a single column. I made no effort to explain the role of winter light in promoting or discouraging dormancy.