UCSC Garden Events for April

The Monterey Bay community benefits from the local presence of a productive and respected university. The US News & World Report’s ranking program places the University of California, Santa Cruz within the top 50 of the world’s 1,250 universities. This impressive ranking is based on multiple indicators, but because this column is on gardening, we focus on this noteworthy institution’s upcoming garden-related events. (Links for detailed information are listed below.)

April 7th — Opening of “Forest (for a thousand years…)” — This event is a “beguiling and uncanny audio installation” staged in the redwood grove of UCSC’s Arboretum. This immersive 22-channel audio piece will continue through June 30th, from 10 a.m. – 5 p.m. Canadian artists Janet Cardiff and George Bures Miller will discuss their work on Friday, April 6th, 7–9 p.m. at UCSC’s Digital Arts Research Center.

April 7thFirst Saturday Tour of the Arboretum & Botanic Garden. Meet at Norrie’s Gift & Garden Shop at 11 a.m. A guided tour is free with admission to the Arboretum.

April 14thSpring Plant Sale. Members pre-sale 10 a.m. – noon; Open to the public noon – 4 p.m. In partnership with the California Native Plant Society, the Arboretum’s Spring Plant Sale will offer quality, regionally friendly plants from both groups at great prices. Watch for more information in these pages prior to the event.

April 15thArboretum Phenology Walk. Sunday, 11 a.m.–1 p.m. Do you enjoy watching plants change through the seasons? Would you like to be a part of a national effort to monitor the effects of climate change? Advanced registration is recommended.

April 25th — “Amah Mutsun Relearning Program,” with Rick Flores. Flores will discuss the collaborative work by the Amah Mutsun Tribal Band and the Arboretum to assist the Tribe’s efforts of cultural revitalization, recuperation and relearning of dormant cultural knowledge, and environmental justice. This 10 a.m. to 2 p.m. session is part of the Volunteer Enrichment Series. Each session is open to the public and free, with priority registration given for prospective and currently active volunteers. Contact Katie Cordes, Volunteer Coordinator, with questions (831.502.2300, cscordes@ucsc.edu).

April 26th & 27th — Seedbed — A Soil Symposium. This free interdisciplinary symposium on the state of soil will feature performances, interactive activities, and visual artwork installed throughout campus. Panel presentations will take place in the Cowell Ranch Hay Barn exploring a diverse range of topics from microbes to waste management, labor and farming; the magic of composting and soil science. The symposium will explore how climate change and human industry have endangered our topsoil – rendering it deadly– as well as the amazing life-sustaining potential of what we call “dirt.”

April 28th & 29th — Farm & Garden Spring Plant Sale. All plants are organically grown and include a wide selection of annual vegetables and flowers, along with wonderful perennials for the landscape. Plants are selected for their proven performance in the Monterey Bay region. Corner of Bay Street and High Street at the base of campus, Saturday 10 a.m.– 3 p.m.; Sunday 10 a.m.–2 p.m.

April 28th — Free Tour of the UCSC Farm, 10 a.m. – 2 p.m. Take a free, docent-led tour of the beautiful 30-acre UCSC Farm. Learn about the education, research, and outreach work that is taking place through the Center for Agroecology & Sustainable Food Systems. No reservations necessary. Meet at the Hay Barn on campus for the short walk to the Farm. Free parking available at the Hay Barn.

April weekdays — Visit the instructional greenhouses operated jointly by UCSC’s Divisions of Physical and Biological Sciences and Social Sciences, and located on the roof of Thimann Labs. This facility has a botanical collection as well as a lab, library, outdoor seating areas and staff representation to facilitate its appreciation. Open weekdays for free visits from 9 a.m. –3 p.m.

April all days — Self-guided walks through the Arboretum 9 a.m. – 5 p.m. every day except occasional holidays. Admission is $5 (18+) $2 (6 –17); free (<6).

This month’s diverse activities offer opportunities to broaden your gardening perspectives and gain familiarity with UCSC’s several garden-related programs.

For more information:

Removing Elements to Improve Your Landscape

The annual landscape review, which was our recent focus, amounts to keeping, improving or removing elements of the landscape. We suggested an approach to review categories of the landscape elements: hardscape, larger plants, smaller plants, and special facilities. Review that column here.

Today’s column addresses the removal of larger plants. The reasons for a removal of a tree or large shrub include not healthy, badly located, or poorly maintained. A large tree growing close to the home could present a fire hazard, or its roots could be lifting nearby pavement.

Taking out an established tree or large shrub could require substantial effort and cost, sometimes including commercial services. On the other hand, removal of a significant plant could yield a great aesthetic change in the landscape’s appearance and an opportunity to introduce one or more new plants in pursuit of landscape objectives.

In other words, replace a loss with an opportunity.

Removing a large plant could include resistance to change in addition to avoidance of related energy and expense. It can be a big decision. Once the homeowner has prioritized a removal, dwelling on the landscape benefits can be helpful to “getting to the root of the matter.”

Speaking of roots, the task of removing a plant should always include removing the roots. Leaving a stump in place might reduce the cost or effort of the project, but leave new problems. The obvious downside is that the stump continues to occupy space in the landscape, precluding a direct replacement. I often see an old stump that is an eyesore in a home’s parking strip.

Also, the stump of a healthy tree or shrub could sprout, even after months of apparent inactivity. Plants strive to survive!

Smaller stumps can be dug out with a shovel, an ax or a Sawzall, and perhaps a pickaxe. The objective is to remove the crown of the plant, plus major nearby roots. It’s not necessary or practical to chase the outreaching roots unless they are lifting pavement. This is likely to be time consuming and dirty work that might inspire hiring assistance. One helpful hint: when cutting down the plant, leave a long stump to provide leverage for loosening the roots.

When the stump is out of the ground, it’s time for a pat on the back and planning for good use of the reclaimed space.

Larger stumps require professional services. Commercial trees services often will include stump removal or provide references to local specialized services. In either case, ask if equipment of the appropriate size will be provided. An overly large stump grinder can disrupt areas adjacent to the target. A smaller unit (some are even hand-held) can provide a precise removal, which could be important when working close to pavement or desirable plants.

Stumps also could be moved with chemicals (potassium nitrate). This process accelerates rotting of the wood in a few weeks, after which it could be chopped out or burned out. For more information on this approach, visit www.familyhandyman.com and search for “stump removal.”

The final thought on this subject is that some trees or stumps should be removed, and the landscape can be much better as a result.

Annual Review of Your Landscape

An annual review of your home’s landscape helps in the long term to raise your level of satisfaction with your surroundings. You will either gain appreciation for that landscape’s good qualities, or establish goals for improvement. In many cases, the likely outcome would be a combination of these results.

You could conduct such a review at any time, but early spring (right now) presents a good opportunity because the seasonal arrival of warm weather stimulates both the plants’ budding and the gardener’s enthusiasm.

This column suggests an approach to landscape review, in search of an orderly and productive process. The approach outlined here is one of several possible ways to go about such a review. Feel free to modify it to accommodate your local situation and preferences.

Begin with an inventory of features of your landscape that you like. For example, these might include hardscape elements, e.g., a wall, patio, pool, stairway, pavement, or garden structure.

Another category for this inventory of Liked Features includes larger trees and shrubs that are healthy, well grown, maintained, and located.

Then, consider planting beds and lawn areas, with emphasis on good size, good placement, and interesting shapes. Are smaller plants, e.g., herbaceous perennials and grasses, in good condition?

Finally, list specialized features, e.g., play areas for children or adults, cooking facilities, and furnishings for dining or relaxing. Relevant criteria: are these features still needed and still used?

Next, using the same categories, identify the features that you don’t like. List the hardscape elements that need repair, maintenance, or, for those that are no longer needed or used, removal.

Identify trees and shrubs (and stumps) that do not meet the criteria listed above, i.e., not healthy, badly located, poorly maintained, etc.

Moving on: are planting beds and lawn areas too small or too large? Are they poorly shaped? Are smaller plants, including lawns, in poor condition?

Then, identify specialized features that are in poor condition, no longer needed, or not used.

Document your inventories of liked and not liked features. The record can be simple and informal, such as a handwritten list on a single piece of paper, and still provide a useful reference for planning purposes.

Develop an action plan. In most cases, the first priority should be the Not Liked Features. Using the inventory, flag each of them for Improvement or Removal.

Barriers to Removal actions might include an excess of nostalgia, a lack of time or energy, or significant expense. Lacking a magic wand, you must deal with such barriers in your own creative way. The removal of large hardscape items or trees could require professional help and related costs but could provide major steps toward landscape improvement.

Improvement actions might require time and energy, or even professional assistance. A good strategy is to prioritize these actions, working first on those that can be accomplished with the least time, energy and expense. The benefits gained from these improvements could motivate proceeding to the more challenging tasks.

The next priority is Replacement of Not Liked Features that have been removed. Every removal might not require direct replacement but might produce a gap that needs filling. This “one step at a time” approach should avoid any confusion that might result from concurrent efforts to improve, remove and replace.

A future column will deal with Additions to the landscape, after completion of the tasks outlined above.

A review of your landscape can be an interesting and creative exercise for you and your significant other, and perhaps an independent observer whose brings relevant skills and diplomatic honesty to the task. Enjoy!

Arboretum Curator Talks Coming Up

If you are interested in the plant collections at the Arboretum and Botanic Garden at the University of California, Santa Cruz, you could learn about them from a new series of talks by the Arboretum’s curators. These professional horticulturists have been long-time developers of the respective gardens for which they have been dedicated for quite long times. They know their plants!

These talks are included in the Arboretum’s new Volunteer Enrichment Series, scheduled on Wednesdays during the coming winter and spring seasons.

As you might already know, the Arboretum’s plant collection reflects the world’s summer-dry or Mediterranean climate zones, which include California. If your garden has basically favorable conditions of sun exposure, drainage, and soil quality, any Arboretum plant you might see and find particularly attractive and suitable for your landscape would grow well in your garden.

That welcome compatibility means that these talks could help you to identify desirable additions to your garden, as well as providing a brief botanical education in a friendly environment.

The first talk, scheduled for March 21st, will be “Exploring Amazing Australian Plants,” presented by Curator of the Australian Collection Melinda Kralj.

The Arboretum has the largest collection of Australian plants outside of Australia! The Arboretum has a great variety of these plants, with one of the features being the Australian Rock Garden, which has been planted with many beautiful smaller plants that would be fine additions to the typical residential garden. ((Selected plants are available for purchase at Norrie’s Gift Shop at the Arboretum.)

Melinda Kralj is a UC Santa Cruz graduate (1978) with degrees in Biology and Art. She joined the Arboretum staff in 1989. Her many activities include guiding the Aussie Weeders, a group of exceptionally cheerful volunteers who work on the Australian Collection on Thursday mornings.

People attending Melinda’s talk should come to the Horticulture 2 building at the Arboretum at 10:00 a.m. The talk continues to 2:00 p.m., including a walk through the Australian Collection.

Upcoming talks in this series are as follows:

April 25th —Amah Mutsun Relearning Program, by Rick Flores, Curator of the California Natives Collection

May 9th —Nursery & Propagation, by Nursery Manager Helen Englesberg

May 23rd — New Zealand, by Tom Sauceda Curator of the New Zealand Collection

June 13th — Succulents, Cacti, Aroma & South Africa, by Executive Director Martin Quigley and Linda McNally

All of these talks are open to the public and free of charge. There will be opportunities for people to become a volunteer at the Arboretum but there’s no commitment to do so.

The Arboretum’s Volunteer Enrichment Series adds another of the many benefits provided by UCSC to the local community.

Gopher Cats

The most devastating tragedy in gardening when a favored plant topples, suddenly dies, or even worse for a smallish specimen, disappears as it’s pulled underground.

The creator of such tragedies is the gardener’s nemesis, the pocket gopher. There are several genera and species of these creatures. In California, we most commonly have Botta’s Pocket Gopher (Thomomys bottae), named after Paul-Émile Botta, a naturalist and archaeologist who collected mammals in California in the 1820s and 1830s. Perhaps he appreciated this particular mammal’s qualities and did not see it as just a pest in the garden.

Gardeners have access to multiple strategies, tools and commercial services for battling with gophers over territory. Some do-it-yourself tools, e.g., stainless steel gopher baskets, will cost almost as much as a plant at the garden center. Still, the basket costs less than replacing the plant. The University of California’s Integrated Pest Management Program has provided a useful overview of the problem of gopher in the garden. 

For several years, my garden has not had gopher visits. As I heard the frustrations and complaints from other gardeners, I felt that I had been lucky, or that my garden was somehow unattractive to gophers. I concluded that two feral cats that I saw in my garden were controlling the local population of gophers. My role was limited to tolerating and not feeding the cats: a well-fed cat would not be an effective hunter.

Eventually, I no longer saw the cats in my garden. I’d like to think another gardener has recruited them, or that they had wandered off for better hunting opportunities. Most likely, they retired.

Without the cats, I soon saw signs of gophers in my garden. After tinkering with traps without immediate success, I decided that a predator would be the ideal solution to the gopher problem. Gophers have many natural enemies, including owls, hawks, coyotes, foxes, skunks, badgers, bobcats, weasels, and snakes. These predators might visit my urban garden occasionally, but a more practical plan would be to have a well-oriented cat in residence, always watching for prey either for a meal or for amusement.

I have recently seen an unfamiliar cat roaming around my garden. Feral cats are, by definition, not accustomed to contact with humans, and tend to keep their distance. The challenge is to persuade such a cat to spend a lot of time in my garden, stay outdoors, and hunt for gophers.

Public and private agencies seeking to control feline populations will vaccinate and spay or neuter feral cats, so it would be best for a gardener to adopt a gopher hunter that had received such treatment. The attending specialists also could advise on training the cat for its role as a resident predator of gophers. My role might be limited to providing water and a place to sleep. As the cat becomes accustomed to my presence, I might show approval for a gopher catch, and disapproval of a bird catch.

I will add this gopher cat project to my resolutions for the early weeks of 2018, along with spraying my apple trees and pruning my roses.

Speaking of roses, last week’s column stated incorrectly that modern garden roses began in 1967. The correct date is 1867, with the introduction of the first hybrid tea rose, ‘La France’.

Best wishes for your new year in the garden!

Naturalistic Landscaping

Several months ago, wrote about a remarkable book by Thomas Rainer and Claudia West: Planting in a Post-Wild World: Designing Plant Communities for Resilient Landscapes (Timber Press, 2015).

In that book, Rainer and West present interesting, insightful and inspiring ideas for landscape design. Central concepts include interlocking layers of plants that grow compatibly in nature, while creating landscapes that are naturalistic but “more robust, more diverse, and more visually harmonious, with less maintenance.”

Some of their concepts, in plainer language, are the following:

“Plants are social creatures” —This thought advocates close planting of natural companions, rather than isolating plants from each other, separated by areas of organic or inorganic mulch.

“Plants are the mulch” — This catchphrase points to the practical value of close planting as a strategy for blocking weed growth and thereby reducing time and effort.

The Rainer/West vision, while complex, is predominantly optimistic. Their book is certainly worth reading. My review, titled “Designing Naturalistic Landscapes,” is archived here.

A reader of this column who had previously read this Rainer and West book observed that the style they described emphasizes landscape uses of herbaceous perennials and annuals in a climate with year-round rainfall. By contrast, while California has “lots of shrubs and sub-shrubs with some annuals” and a summer-dry (Mediterranean) climate. The reader asked how to go about adapting the style presented in this book to our California climate, and where in California has such a garden been created.

These are worthwhile questions. The authors recommended drawing on locally relevant resources, e.g., the California Native Plant Society. Also, my column referenced a book by Glen Keator and Alrie Middlebrook: Designing California Native Gardens: The Plant Community Approach to Artful, Ecological Gardens (University of California Press, 2007).

There are more relevant resources available online, notably Thomas Rainer’s Grounded Design website.

Gardeners also have access to many books on Mediterranean climate plants and especially California native plants, but such books typically describe individual plants in alphabetical order rather than in the “interlocking layers” envisioned by Rainer and West. We encounter the same organizational model in mail order plant nursery catalogs and in local garden centers, so many garden designs amount to scatters of single specimens.

The Rainer & West style was published fairly recently, so there are few California landscapes that are based on this style. The Keator & Middlebrook book cited above approaches that concept by grouping native plants within particular regions of California (e.g., coastal scrub, grasslands, deserts, oak woodlands), but leaves it to the garden planner to adopt fully the Rainer & West style.

One might seek exemplary designs in gardens included in annual garden tours that feature California native plants:

  • Bringing Back the Natives —Gardens in Alameda and Contra Costa counties, early May (http://bringingbackthenatives.net)
  • Going Native Garden Tour—Gardens in Santa Clara Valley & Peninsula, San Francisco Bay Area, early April (http://gngt.org/GNGT/HomeRO.php)

Although the Rainer & West style could take many different forms in California gardens, avid gardeners should keep watch for examples of this emerging approach to landscape design.

Pruning a Fig Tree and Other Plants

Pruning season is upon us. Garden priorities might simply be clearer this year, but the list of pruning tasks has grown dauntingly long.

Cotoneaster berries

Red Clusterberry

One of the most pressing tasks is to shape a Red Clusterberry (Cotoneaster lacteus) that began as a volunteer and grown to dominate one part of the garden. In the past, it has shrugged off significant pruning cuts. A common objective for pruning is to stimulate fruiting, but that is not a priority in this case.

This year’s pruning schedule began with controlling a rampant California wild grape (Vitis californica ‘Roger’s Red’), which had grown without pruning for a couple years, and found its way into the branches of nearby trees and shrubs. Whacking it back has greatly improved its overall shape and should result in a bountiful crop of grapes. I will resolve once again to cover it with netting to protect a fair share of the clusters from unknown midnight marauders.

I have also pruned the new growth on four dwarf apple trees and sprayed them with dormant oil to discourage codling moths. Friends with the California Rare Fruit Growers, noting that moths fly, emphasize the need for neighbors to spray their trees as well, but I see no other apple trees in the neighborhood. I have also planned to cut selected main branches on one apple tree (Malus ‘Cox’s Orange Pippin) to gain some freedom of movement around it. My related resolutions include another spraying one or two more times before bud break, and thinning the fruit when it grows to about the size of a golf ball, to support the development of larger fruit.

My rose pruning project is more than half completed. My approach to hard pruning roses is close to the shearing style described recently in this column. I am also shovel-pruning some under-performing roses and intending to install replacements, with a preference for “own root” roses. Pruning suckers from grafted roses is the downside of whatever benefits might flow from a superior rootstock. Related resolutions: fertilize in the spring and irrigate regularly.

My next pruning focus is a large fig tree (Dorstenia ficus ‘Black Mission’), which dates back to around 1768, was grown in the California missions, and is a very popular fig for home garden cultivation. Fruit tree specialists also recommend several other varieties. Fig trees generally produce two crops of figs each year. The first, called the breba crop, develops in the spring on last year’s growth. The second, the main fig crop, develops on the new growth and ripens in the late summer or fall. My tree has gone several years without pruning, sprawled into large size and produced relatively light crops. Its low harvest might indicate the tree’s age or the effects of drought, but it might simply benefit from pruning. I will prune it heavily during the current dormant period to improve its shape and hope to stimulate a larger main crop.

Here are the basic pruning recommendations.

  • Begins by removing any dead, diseased or otherwise unproductive wood and any sprouts growing from the base of the tree.
  • Then, remove any secondary branches that are growing at a too-narrow angle (less than 45 degrees) from the main branches.
  • Then, cut back the main branches by one-third to one-quarter.

Related resolutions include resuming an earlier plan to establish an espalier form by training branches to posts on either side of the tree, and netting the tree at the appropriate time to protect the ripening fruit from winged wildlife.

My list includes more seasonal pruning tasks, all of which should result in wonderful growth in the spring.

Adding Annual Plants to the Garden

Annual plants can add much to any garden: providing seasonal color for cutting or enjoying in place, discouraging weeds, preserving soil moisture, and feeding birds while growing easily and requiring only as much space as the gardener chooses to commit.

In addition, annuals can fill spaces in the garden temporarily or annually. That’s a priority for me, as I see areas in my garden that need brightening or just something interesting for next spring’s planned garden tour.

The easiest and least expensive way to add annual color to a garden requires simply choosing seeds from the garden center’s rack of packets, and planting the seeds according to directions on the packet. There are many options and planting is very easy. It’s almost as if the seeds plant themselves.

Wait, that’s actually what they do!

In my garden, this process becomes more complicated because of geographically organized beds. The area that needs the addition of annuals is the California/Mexico beds.

The obvious choice would be California wildflowers, but there are hundreds of them, and very few can be found among garden center offerings. A fine mail order supplier is The Theodore Payne Foundation for Wildflowers and Native Plants (http://theodorepayne.org/ ) a non-profit organization in southern California. This group offers seeds for a wide range of California native plants, individually and in mixtures.

I have ordered the Coastal Mixture, which includes annuals and perennials of various heights:

  • Arroyo lupine (Lupinus succulentus) – 12–15” annual, purple & violet.
  • Beach Suncups (Camissonia cheiranthifolia)  – 6–12” perennial, yellow;
  • Blue Thimble Flower (Gilia capitata) – 15” annual, lavender blue;
  • Dune Poppy (Eschscholzia californica maritime) – 6–8” perennial, yellow;
  • Miniature Lupine (Lupinus bicolor) – 3–4’ annual, blue & white;
  • Mountain Phlox (Linanthus grandiflorus) –12–24” annual, pink & white;

Annual plants from Mexico that I’m considering include

Four O’Clock Flower (Mirabilis jalapa) – 36” perennial, various colors on the same plant. A popular garden plant that has been naturalized in a long list of countries of the world. A friend has provided seeds for this “pass-along” plant.

Mexican Sunflower (Tithonia rotundifolia) —72” annual, Orange-red with a yellow center disk. This is a spectacular plant that I have grown before. It rises to full height in 85 to 90 days. Seeds are available online.

All of these plants would grow best when direct-seeded, but I will start the Four O-Clocks and Mexican Sunflower seeds in peat pots, so they could be placed in the garden by design without disturbing their roots.

This should be an interesting spring season! Consider annuals for your own garden.

A Note about Invasive Plants

In a recent column on pruning, I shared a photo of a Red Clusterberry (Cotoneaster lacteus) in my garden and mentioned that I had scheduled it for pruning. A reader advised that this plant is invasive and recommended warning readers of that fact. After checking, I agree and am glad to recommend against adding it your garden. This plant’s invasiveness is based on its vigorous growth, root-sprouting, and proliferous production of fruit. I have observed strong growth, seen only occasional sprouts come up from the roots, and watched birds feasting on the berries. Very few seedlings have appeared under the shrub, but the birds might have deposited seeds in their countless branch offices, out of my view. My garden has the more popular Orange Cotoneaster (C. franchetii) that has produced many more seedlings but has not been described as invasive. If you can’t abide such seedlings, get these plants out of your garden.

Renewing the Garden

Gardeners who accept the changing nature of plants have the most interesting and successful gardens.

Some plants can thrive—or just hang on—for many years. Plants with the shortest life spans are those we call annuals, which sprout, bloom, drop seeds, and fade away in a single season. Actually, these plants continue through multiple generations by going through seed phases each year. This life cycle differs from that of perennial plants, but it’s easy to perceive life continuing for these plants through their regular periods of “seed dormancy.”

Given favorable conditions of soil nutrients, moisture coupled with the desired degree of moisture retention, and the desired degree of exposure to sunlight, most plants will continue for many years.

We must acknowledge the importance of occasional attacks by insects or diseases, but healthy plants are generally capable of surviving such hazards.

The growing environment is most important. Some plants have evolved to thrive under specific conditions. We generally think of plants that grow best in good garden loam, with moderate moisture and six or more hours of sunlight each day, but there are many exceptions to this standard.

Some plants grow well in soil with greater proportions of clay or sand, or with minimal nutrients.

Then there are epiphytes: plants that grow upon another plant or object merely for physical support and live on airborne moisture and nutrients. Kinds of epiphytic plants include lithophytes, which grow on bare rock or stone; chasmophytes, which grow in the crevices of rocks, and cremnophytes, which can grow on cliff faces.

Some “aquatic” plants grow immersed in water. I have recently added an Erebus Canna (Canna glauca x generalis hybrid and an Anytus Japanese Iris (Iris ensata ‘Anytus’) to my pond. Conversely, “xeric” plants manage with very little water. Such plants include succulents, notably, e.g., cacti, aloes, agaves. There are many gradations within this wet/dry range.

Then, we have sun-loving plants and those that prefer very little sunlight and could even burn when placed in full sun. Again, plants have preferences for various levels of exposure.

Other habitat preferences of plants relate to wind intensity, site altitude, air salinity, etc.

All this variation raises the importance of the gardener’s research into a plant’s native environment. Plants have evolved for several generations to flourish under particular circumstances, so the gardener should select plants that could grow well under his/her specific garden conditions, or take reasonable steps to provide the plant’s preferred conditions. Fortunately, many plants can adapt to conditions that are not quite what may be best for them, but they will generally grow best in a spot that resembles their native habitat.

The gardener represents the greatest threat to a cultivated plant’s survival.

The dangers begin with the installation of a plant in a spot that lacks the conditions that the plant requires. This is “right plant, wrong place” problem. The eventual result is a plant that should be moved to a more compatible spot and perhaps replaced with a plant that would be better suited for that location.

At another level, we have plants that have outgrown their original location, so that they are crowding nearby plants, obstructing a garden walkway, or simply being out of scale for the landscape.

Whenever a plant has suffered under incompatible growing conditions or has grown beyond the intended or desired size, the gardener should recognize the problem and correct the situation decisively. A garden visitor might provide an independent yet diplomatic assessment of a particular plant’s misplacement. The gardener should avoid the view that plants are permanent assets or irreplaceable sentimental attachment, and instead accept the occasional need to transplant or recycle a plant, and welcome the concurrent opportunity to introduce a new botanical treasure into the garden.

Managing Weeds

Garden renovation can bring multiple rewards. Re-thinking your landscape can yield opportunities to exercise one’s creativity, pursue recent insights into botanical combinations, add exciting new plants, dismiss too-familiar vignettes in favor of new horticultural frontiers, and discover excuses to “shovel-prune” under-performing plants.

The process also includes several downsides: lots of work, heavy expenses, and the frustration of waiting for the new landscape to develop into its promise.

There’s another downside to consider: enabling the germination of unwanted plants in the weed seed bank.

Experienced gardeners know that their soil harbors an inventory of weed seeds that are lurking a few inches below the surface, waiting for a little sunlight, a little moisture, and presumably a little oxygen. Given those prerequisites, they will burst into growth and the production of another generation of seeds.

The weed seed bank developed in a variety of ways. It might have come from last season’s weeds, or the careless importation of contaminated soil or potted plants, or the tireless efforts of birds, who we suspect are spending their days moving seeds into our gardens. And there’s the wind, which transports the lighter-weight seeds to gardens where they typically are unwanted.

Some itinerant seeds are actually welcome in our gardens, but they are out-numbered by the weed seeds.

Regardless of the origins of the weed seed bank, the important fact is that the seeds are not far from the surface, and they can retain their vitality for years.

Given this reality, consider what happens with a garden renovation project. In my garden, this process included cutting down fifty feet of large shrubs and grinding their roots, digging and replanting scores of native irises, relocating a large number of bearded irises, and planting dozens of new plants from one-gallon and fifteen-gallon pots.

All of this activity has churned the soil and consequently liberated my garden’s weed seed bank. A clear contrast in weed populations can be observed between the disturbed and untouched areas. This requires hours of weeding, with the optimistic goal to pull weeds before they set seeds for next season.

An activity that parallels garden renovation is the sowing of seeds for annual plants, whether for edible or ornamental gardening. The usual advice for planting seeds is to loosen the soil, scatter the seeds, rake them in, water them in, and maintain moisture while the seeds germinate. If your goal would be to activate your weed seed bank, you would go through exactly the same steps!

The Theodore Payne Foundation for Wild Flowers and Native Plants has sent the wildflower seeds I ordered and provided recommendations for leaving the weed seed bank in its dormant state. The basic strategy is to disturb the soil as little as possible and preferably not at all. The Foundation recommends digging or tilling no deeper than three or four inches. Better still, after clearing the planting area of existing weeds, rake the soil gently, scatter the seeds, and cover them with about one-eighth inch of garden soil or light potting soil.

Despite this careful effort to leave weed seeds dormant, the Foundation adds a tip for planting wildflower mixtures: plant a sample of the seed in pots in some fresh potting soil, so you could identify which seedlings in the ground are the desired wildflowers, and which are weeds to be removed. Even when the experts are most careful, weed seeds will germinate.

Battling weeds might be an unavoidable part of gardening, but it can’t deny us the joys of renovating our gardens from time to time and growing annual plants.