Inside The New York Botanical Garden
Gardening Tips
Posted in Gardening Tips on February 9 2009, by Sonia Uyterhoeven
Under or Inter…Planting?
Sonia Uyterhoeven is Gardener for Public Education at The New York Botanical Garden.
What are all these prefixes that we see hanging around the word “planting” and what exactly do they mean?
Sometimes a photograph is worth a thousand words. At right is an example of underplanting at Great Dixter in England, the legendary garden of the late Christopher Lloyd.
Every nook and cranny is filled with plants. Microclimates are naturally created in the garden as taller plants cast shade on shorter plants. At Great Dixter, this is an opportunity for tapestry and texture; fuchsia, begonia, and other shade-loving plants hug the ground beneath taller plants. In the photo, Rolanda petasitis (velvet groundsel) will eventually shoot up to six feet tall, above the fuchsia and fern below.
If you follow the design principles of working with shape, texture, and contrast when combining the foliage and flowers of plants, with a little bit of practice you will start creating beautiful vignettes in your garden.
Interplanting requires a little more knowledge of your plants and their growth habits. Allium (ornamental onion) have beautiful orbicular-shaped flowers, but their foliage is something to be desired. The plant starts off in grand fashion and then starts to yellow before the flower has opened. At Great Dixter, ornamental onions are interplanted with the mounding foliage of hardy geranium such as Geranium ‘Ann Thompson’ and the loose framework of Spiraea x bumalda (bumald spirea).
A good example of interplanting is seen at left, where the building block approach of Fergus Garrett, Great Dixter’s head gardener, is apparent. The foundation of this garden scene is the Pulmonaria (lungwort) that you see weaving through the border. Layers of plants are then added to the mix.
The hardy begonia (Begonia grandis ssp. evansiana) and jack-in-the-pulpit (Arisaema triphyllum) have a tendency to stretch and rise above their companions, adding a new spatial dimension through graduated heights that give a tiered or layered look. Strong shapes, textures, and color create a dynamism that makes it appear as if the plants are skipping through the border. Understanding how plants occupy space is a key element in this design.
Posted in Gardening Tips on February 2 2009, by Sonia Uyterhoeven
Garden Economics
Sonia Uyterhoeven is Gardener for Public Education at The New York Botanical Garden.
While many of us are thinking about curtailing our spending in this economic climate and talk of 
reduction seems more appropriate than expansion, for the plantaholic this could potentially be a sobering year. Fortunately for gardening enthusiasts, our good friends across the Atlantic always have some good advice to offer.
Last summer I spent some time over at the late Christopher Lloyd’s legendary garden, Great Dixter, in England learning from the garden’s life force, Fergus Garrett. Fergus is a marvelous combination of passionate plantsman, colorful and creative designer, and experienced educator who is able to communicate his vision.
During my visit he imparted many important design lessons that I will share with you in this and future blog posts. The gardens at Great Dixter are full; in fact they are exploding with plants arranged in a glorious display. Fergus is a big proponent of interplanting and underplanting. No space is wasted in this economical vision.
The question of any seasoned gardener who has undoubtedly experimented with cramming as many plants as possible into a limited space only to see the creation collapse is “How do you make it succeed?”
Fergus has a multi-layered approach to design. He creates his borders the same way you and I would put together a jigsaw puzzle. He works in a piecemeal way—starting with a few initial pieces and then building and slowly improving on the scene. In this design process, he is constantly exploring the seasonal dimension of the borders, the shapes involved, and the partnerships and interactions that are forming between the plants.
As an experienced plantsman, one key component in his design process is to understand and work with the space that plants need to thrive, either individually or in groups. In the example pictured here, he ingeniously works purple clematis into a hardy fuchsia (unfortunately, not hardy in New York).
The clematis benefits from the support of the lanky stems of the fuchsia, which allows it to climb through in an unhindered and happy fashion. The large, flat shape of the clematis contrasts beautifully with the small tubular flowers on the fuchsia. The design is completed with the color echo of the purple clematis and the dangling purple petals on the fuchsia, both dramatically offset by the fuchsia’s bright red sepals and stamens.
As seen in the photo, the plants form what Fergus refers to as a happy union or marriage, where the plants bring out the best in each other and sustain or support each other as they grow. Next week we will explore his practice of layering plants in more detail.
Posted in Gardening Tips on January 26 2009, by Sonia Uyterhoeven
A Weedy Mess: Keeping My Life in Order
Sonia Uyterhoeven is Gardener for Public Education at The New York Botanical Garden.
I am always surprised by the long weekends we have in January and February. I seem to remember all the holidays except for the ones that sneak up in mid-winter. Since I never plan for them, they turn into three days of extended housecleaning. The piles on my desk diminish and bills finally get filed in the right place. During these moments, I swear to good housekeeping practices that I never abide by.
Gardening is much the same. If I abide by a few simple rules and good horticultural practices then I won’t find myself swamped with one big green, leafy mess. Today, I will focus on just one aspect of horticulture: good weeding practices. Here are a few simple tips to make weeding easier.
- Keep your garden a reasonable size: Don’t be over ambitious. Be honest about how much time you intend to spend in your garden and how much work it will take.
- Stagger your spring planting: Freshly cultivated soil is an invitation for weeds. If you plant your beds all at once, you will be weeding them at the same time. Stagger you planting over a few weeks.
- Low maintenance plants for the low maintenance gardener: If you don’t like weeding, choose plants that out-compete weeds. Select plants with broad foliage and heavy branching or ones that are large, tall, or vigorous growers. If the plant is doing its job of filling up the space, there will not be enough room or light for weeds to enter.
- Weed often: It’s important to weed often not only to keep weeds at bay, but also for your general health. If you try weeding your entire garden all at once, you will have sore muscles at the end of the day.
- Attack flowering weeds or weeds that are about to flower first: If you let weeds go to seed, you will have an uphill battle. Prioritize by removing flowering weeds first.
- Weed early in the season: Tiny weeds are easier to pull than big weeds. Early weeding also gives the plants you want in your garden a better chance of becoming established.
- Hoe when dry, hand when wet: If your soil is dry, run a hoe through your garden. Weeds exposed to hot sun without any water will shrivel up and die in no time. Rake off the debris. If you try using a hoe when your soil is wet, weeds will simply re-root. When your soil is wet is the time to tackle deep-rooted weeds like dandelions—they will be much easier to pull
.
Posted in Gardening Tips on January 20 2009, by Sonia Uyterhoeven
Easy Design Steps for the Home Gardener
Sonia Uyterhoeven is Gardener for Public Education at The New York Botanical Garden.
A few years ago I designed a French kitchen garden (potagér). I was under a time constraint to come up with ideas, so I fell back on some good advice that I was given at the beginning of my career. “Why do things on your own when you can always solicit the help of others?” In terms of design, the easiest way to do this is to make use of a good library. Books are full of good ideas that can be borrowed and transposed into your own creations.
My initial task was to construct a framework for the garden. Raised beds provided a structure for much of the garden, but an extensive open area was up for grabs. Did I want an orderly, linear display in this area or flowing swaths of texture and color comprised of a conglomerate of herbs, flowers and vegetables?
The answer was my typical “Let’s try a little of everything.” I found a wonderful illustration of a kitchen garden that contained tidy, linear rows that were separated in the middle with a bountiful oasis of flowers and herbs.
In the illustration an espalier of apples lined the sides of the middle expanse and acted as a transition from the linear vegetable rows to the free-flowing flowers. In my design I replaced the espaliers of apples with an espalier of tomatoes. This idea came from another book that described unusual ways to stake your tomatoes.
Once I had decided on the overall structure, the rest of the design quickly fell into place. Vegetables filled the raised beds, herbs and flowers spilled over the edges. Cute little ‘Tumbling Tom’ tomatoes spilled over the side of one bed lined by colorful ornamental peppers. With the structure in place, it was now a matter of selecting my choices from a myriad of vegetables and herbs.
Attention was paid to companion planting—potatoes joined peas in one bed, nasturtiums frolicked with tomatoes in another and rue snuggled up to a fig. Containers of sweet peas were supported by homemade teepees made from bamboo stakes. Marigolds skirted the sides in a hopeful attempt to ward off aphids.
Designing gardens, whether for vegetables or flowers, can be fun and easy. Borrowing ideas from other sources is a great way to start. Begin the process by staging your garden scene with a structure or a framework. Then carefully plug in the plants and any decorative elements.
Designs work best when you work with different layers—different heights, different shapes, different textures. To ensure that you do not end up with a cacophony of colors and textures, remember to apply the design principles of unity and repetition. A good design should form a coherent whole. Repetition of color, shapes, and textures are an easy way of creating a sense of continuity.
Winter is a wonderful time to sit down with design books and catalogs to start planning the gardening year ahead. Have fun.
Posted in Gardening Tips on January 12 2009, by Sonia Uyterhoeven
Winter Wonderland
Sonia Uyterhoeven is Gardener for Public Education at The New York Botanical Garden.
The Garden looks like a winter wonderland when it snows. The quiet and calm of the white landscape is deceptive. The aftermath of a storm causes us to scurry around shaking the snow off hedges and prized evergreen shrubs as well as clearing paths and benches.
The yew hedge that delineates the perennial garden struggles under the weight of wet snow. Brooms and rakes (not shovels) are used to gently remove the snow. The snow blowers are instructed to point their machines away from the hedge to minimize unnecessary damage. When removing snow in your own home gardens, push upward with the broom rather than downward to minimize pressure. Remember not to use hedges and foundation borders as dump sites for excess snow.
Snow acts as an excellent insulator during the cold winter months. Small plants can remain covered, but larger or more fragile plants need to be shaken off to ensure that their branches are not disfigured or broken by the weight of the snow.
If you have a narrow, upright conifer (such as an arborvitae) that you are worried will lose its shape, tie susceptible branches with nylon tree ties or arbor ties that you can purchase at a garden center. If you are curious to see how this is done, come and inspect the small arborvitae located at the Fountain of Life in front of the library building. We carefully tie these trees in November. An alternative solution is to place a stake at the back of the tree and loosely wrap garden twine around the tree and stake starting at the bottom and moving upward. This can also be done without a stake by simply attaching the twine to the trunk of the tree and winding the twine around the branches.
These simple yet important steps are taken to ensure that the landscape of the Garden is not only beautiful but also well maintained throughout the winter and into the spring. They are easy for you to do in your own home gardens.
Posted in Gardening Tips on January 5 2009, by Sonia Uyterhoeven
Fragrant Wintersweet (Chimonanthus praecox)
Sonia Uyterhoeven is Gardener for Public Education at The New York Botanical Garden.
They say that nature is about observation, but sometimes it is about just following your nose. Chimonanthus praecox is one such example. It is an underused winter flowering shrub that is often eclipsed by the more popular Hamamelis (witch hazel).
Fragrant wintersweet is a deciduous shrub that is hardy to zone 6b. It tends to be a multi-stemmed, loose-stemmed specimen with a fountain or vase-like shape. It does not have the structural composure that witch hazel possesses. It can get a little gangly with age. Happily, this 10- to 15-foot shrub can be severely cut back after flowering.
The main feature of this shrub is its fragrant winter bloom. It just started flowering in the Home Gardening Center (it’s planted behind the Sensory Garden) in mid-December and should remain in flower through the cold winter months.
It has small half-inch to 1-inch long flowers that look like shredded little cups. The inflorescence (floral structure) is broken down into layers. The outer layer has flat strap-like, waxy, yellowish-white, translucent tepals. The smaller tepals on the inner layer are burgundy. They are also translucent and remind me of what a first coat of burgundy nail polish looks like on your nails. What’s a tepal? It is the botanist’s name for when the flower part (sepals and petals) all look undifferentiated.
Never mind the anatomy, how about the fragrance? It has a pungent smell that is spicy and exotic. It reminds me of ylang ylang, the type of fragrance that gets trapped inside your nostrils.
With its pungent perfume and its poetic little flowers, can we then speculate on how Chimonanthus is pollinated? The general rule of thumb is that trees and shrubs with small, inconspicuous flowers are most likely wind pollinated. They don’t need to put on a show to attract a pollinator; they simply need to extend their branches so their pollen can get caught in a passing gust of wind.
Woody specimens with large, showy flowers and enticing perfumes tend to be insect pollinated. They lure their potential pollinators with sweet smells and sugary nectars. But who in their right mind would be flying about in the middle of winter?
When we look to other winter-flowering shrubs for clues, we are given none. Members of the Hamamelidaceae family such as witch hazel produce fragrant flowers during the winter. These woody plants are wind pollinated, although, curiously enough, fossil evidence indicates the possibility they were once insect pollinated.
Chimonanthus praecox is in the Calycanthaceae family. Members of this family are generally either fly or beetle pollinated. Small, open flowers tend to be fly pollinated while larger, intricate flowers are designed to trap beetles.
Is this exotically fragrant shrub then fly pollinated? The burgundy markings on the inner tepals and its graceful open whorl-like floral structure would suit that pollinator. But in the middle of winter?
Maybe in its native China there are small hovering flies or beetles buzzing around when the shrub is in flower. Here in New York, however, we have decided that Chimonanthus praecox is “nose-pollinated.” That is, it’s fragrance is so enticing that once you dip your nose in for a small whiff you will be back for more.
Posted in Gardening Tips on December 29 2008, by Sonia Uyterhoeven
Looking Back at the Year
Sonia Uyterhoeven is Gardener for Public Education at The New York Botanical Garden.
I was fortunate enough to spend two weeks in the Southeast of England this past July. As I toured around a handful of gardens, one thing that made a lasting impression was the size of the plants. With their cool summers and ample rainfall, perennials that grow three feet tall in the New York area were happily stretching up to four or five feet.
On this side of the pond the past year felt distinctly British. Spring lasted for more than a quick two-week spell with the cool weather and rain that extended well into May. July certainly had periods that were hot and the rains came infrequently in heavy downpours; the tropical plants in the Garden took notice and jumped into their full glory. August surprised me. Instead of the stifling heat and insufferable humidity that I have grown accustomed to, it was pleasant. The intense heat never came.
These are the moments that I wish I had a crystal ball. Had I known this ahead of time, I would have filled my perennial borders with lupines, penstemons, and delphiniums. I would have also cut back some of my larger, floppier customers such as the Montauk daisy (Nipponantheum) even harder than I normally do.
The ornamental grasses grew taller than I was accustomed to and needed more staking than in previous years. Many plants doubled in size and spread happily through the garden. My catmint (Nepeta) lost its sense of time and did not know when to stop flowering. Along with the lavender, it sent up sporadic blooms through the summer and well into fall. My Virginia sweetspire (Itea) decided that fall had come early and started to show its fiery reds as early as mid-August.
Observation is one of the finest tools that gardeners can posses. Gardeners not only work with plants, they work with nature. Observing nature and watching how changes in the environment directs and affects the growth and the cycles in the garden is one of the greatest gifts. It teaches gardeners more about plants than any textbook ever could.
Posted in Gardening Tips on December 22 2008, by Sonia Uyterhoeven
Lessons in Biodiversity and Sense of Place
Sonia Uyterhoeven is Gardener for Public Education at The New York Botanical Garden.
I recently attended a lecture on the art of ecological garden design and found a great deal of inspiration from the speaker’s ideology. I was reminded of the importance of a “sense of place.”
This is a design concept that has been around for years, but it was forcefully driven home with the reminder that a generic landscape—let’s say for the sake of simplicity a home surrounded by a green lawn—gives the viewer no sense of locality. You could be in Arizona, Alaska, Alabama, or anywhere in between.
With it comes the poignant reminder that we “no longer know where we are” and lose a sense of “who we are.” There is a loss of culture and tradition that disappears with the absence of locality.
Every part of the country has its own particular flavor.
If you are looking out your window and you see the knobby trunk of a pitch pine (Pinus rigidia), a beach plum (Prunus maritima), and expansive carpets of bearberry (Arctostaphylos uva-ursi) and broom crowberry (Corema conradii) covering sandy soil, then you are probably on Cape Cod. This is an image that is laden for many with certain associations, smells, and memories—generally good ones.
It is a memory of a diverse environment. This guru on ecological garden design reminded me that the experientially rich environment is full of textures, colors, movement, and sounds. With diverse plant palates comes the concomitant diversity in wildlife—the welcome as well as the unwelcome kind.
Monocultures often appear to be static and sterile, while one of the greatest joys of a natural environment is its dynamic system that celebrates seasonality. If beauty and abundance is not enough to convince the reader of the importance of diversity, then know that an ecological garden works with its surrounding rather than against it so is much less of a maintenance challenge. It certainly doesn’t require the quantity of chemicals that we have to dump into our lawns to keep them green.
Does this mean we should do away with the generic lawn? Certainly not! I would hate to lose the spot for the lawn chair, the badminton game, or the barbeque. With a little planning we can have the best of both worlds—patches of organically maintained lawn woven into a diverse and ecologically sound garden. This is how we can flourish and grow into the future.
Posted in Gardening Tips on December 15 2008, by Sonia Uyterhoeven
Growing Herbs Indoors
Sonia Uyterhoeven is Gardener for Public Education at The New York Botanical Garden.
As winter winds chill your bones, some of your summer pastimes can be successfully re-created in the home. One of my favorites is growing herbs on a windowsill. My biggest challenge is overuse. Healthy plants get nightly haircuts until they dwindle into a small patch of nothingness.
For those of you who are able to exercise better restraint, many herbs can be grown indoors and will happily survive on a sunny windowsill. Basil, chives, parsley, thyme, and oregano are easy to grow. Rosemary is trickier to grow as it needs a cool room (around 60°F) and high humidity. Most herbs require six hours of sunlight to thrive. Bright southern or western exposure is best. Parsley, rosemary, and mint can take less light.
All herbs are unhappy with the dry, stagnant air common in homes during the winter months. Some antidotes: occasionally crack open a window or periodically run a small oscillating fan; keep household temperatures in the 70s; mist plants daily, place them on top of a pebble tray, or invest in a humidifier that will benefit both you and your green guests.
Use water at room temperature for herbs. Some such as marjoram, oregano, sage, and thyme need to dry out between watering—meaning when the soil surface is dry. Rosemary and mint will resent dry periods and shouldn’t be allowed to completely dry out. Make sure that water doesn’t collect or sit on the leaves of your herbs, otherwise they will rot. Basil is particularly susceptible.
Indoor herbs, like all of your houseplants, will gather dust and will require an occasional bath. Take a soft sponge or paper towel and clean the leaves. Alternatively, gently run it under the shower or the tap. While herbs don’t need fertilizing when they are growing outdoors, a monthly boost of half-strength fish emulsion will help keep your winter windowsill herbs thriving.
If the herbs are moving from outdoors to indoors they should be potted up before the first frost. If they undergo a reverse hardening off procedure they will have a better chance of adjusting to your home environment. Place the containers in a slightly shady area for a week to prepare them to the lower light levels of the home. Gradually bring them in for a few hours every day until you are ready to provide them with a new home.
When bringing your herbs indoors from the garden, many will benefit from being cut back by half. Some examples are rosemary, mint, sage, thyme and oregano. Remember that herbs love haircuts—it keeps the growth nice and tender and tasty. Growing herbs in your home is fairly easy; the hardest choices you will face is whether you should put them in your salad or on the roasted chicken.
Posted in Gardening Tips on December 8 2008, by Sonia Uyterhoeven
Snow in the Garden
Sonia Uyterhoeven is Gardener for Public Education at The New York Botanical Garden.
Snow is one of nature’s greatest insulators. As long as it is not crushing a plant or placing too much weight on vulnerable branches, why not let it naturally pile up. It shouldn’t be a problem; in fact, it may actually help the plant weather the season.
In the Garden, we do have areas where we need to remove snow such as from our yew hedges, which could be damaged and disfigured by heavy snow. We gently remove heavy snow from hedges and specimen trees by using a broom or broom handle and slowly pushing upward. If the snow has iced over, we wait until the sun warms it up.
Do not try to break off ice crystals or be too hasty in your treatment. The trees and hedges are stressed enough in the winter months and patience is one of your greatest virtues. Avoid using a shovel; it tends to be too heavy, unwieldy, and sharp and will damage branches. If you are in a hurry or have a large area to cover, try a snow blower on low volume.
Mark your driveway with reflectors so that you delineate areas to be plowed before the snow piles up. Do not shovel or plow snow onto valuable trees and shrubs. While this sounds like common sense while sitting at your computer, this decision is not always straightforward when you are holding a shovel full of heavy snow. Not only will the force damage branches, but you will be piling up harmful salt residues.
Be careful of damaging plants with salt runoff from paths and sidewalks. Salt burns plants and kills root systems. Rather than using sodium chloride, try products that contain calcium chloride or magnesium and potassium chloride. Two products that do less damage to plants and that you can easily find at a hardware store or The Home Depot are Lescomelt2™ and Combotherm™.
If salt damage does occur, use gypsum (hydrated calcium sulfate) to counteract the salt at a ratio of 20 pounds per 100 square feet. As with any product, read the label and follow the directions for best results.
