The word “garden” is being redefined. If it’s your sanctuary and the place where, hands in the dirt, you commune with nature, it’s a garden. This might mean five acres in the country or a tiny urban oasis, the deck off the family room, a balcony in the sky, or merely a stunning urn by the front door.
Container Gardening Tips
Perhaps the fastest-growing area in the gardening world is that of container gardening. At a recent workshop hosted by Botanic Heaven, a garden center in Chicago’s west end, and led by senior manager John Rose, a group of garden writers experienced this evolving and increasingly sophisticated art form. As a result, a spiky dracaena surrounded by a couple of geraniums will never again suffice, at least not in my containers.
Here’s how you can create your own traffic-stopping container garden designs.
Garden Container Prep Work
Before creating your masterpiece, Peter Dalia recommends the following:
First, make sure that you water all plants in their store-bought pots or cell packs.
Leave two to four inches (five to eight centimeters) between the top of the soil and the container’s rim to allow water to slowly penetrate the root system rather than run off the surface.
What’s the best location for your plant container?
Think about where you want to place the container. Select plants that favor similar growing conditions (such as sheltered or not, full sun or shade, moist or dry soil), yet have different bloom times and growth habits. For high-traffic areas, think about adding fragrant foliage plants such as rosemary, lavender, and thyme.
What is a good garden container design?
Many fail to capture the essence of good container design. In container gardening, anything goes. Cultivate your creative gardener within by mixing and matching colorful tropical (indoors), perennials, and annuals.
Consider a mix of annuals, tropical plants, foliage only, or perennials, shrubs, herbs, summer bulbs, ornamental grasses, small evergreens, and vines, are all appropriate. It’s your choice; you are in charge of your container plants.
Thrillers: the upright, tall, eye-catcher placed either in the center or off-center in the container; plant it first. For a tropical look, try taro (Colocasia spp.), elephant’s ear (Alocasia esculenta), cannas, papyrus (Cyperus papyrus), banana plants (Musa x paradisiaca ssp. sapientum), or a tall ornamental grass.
Fillers: Fillers are great to take up mid-ground space without distracting from the thriller. Lantanas, coleus, salvias, parsley, low-growing grasses, begonias, and many other flowering plants and foliage fall into this category.
Spillers: These are plants that flow over the edges of your containers: sweet potato vines (Ipomoea batatas), ivies, trailing geraniums, and petunias, Bidens ferulifolia, and no doubt many more discoveries you’ll make at your local garden center.
Try using your favorite shrub, roses, a small Japanese maple, an azalea standard, or your favorite shrub or evergreen as your container’s star. In the fall, remove perennials, shrubs, and trees from containers. Plant them in the garden three to six weeks before the ground freezes.
Plant Container Design Tricks
One of the tricks of excellent container design is to plant a few specimens that will strut their stuff in August and September just as everything else is starting to look a tad weary. This is where summer bulbs come into their element.
Plant bulbs (at the depth recommended on packaging) before adding any other goodies. Then wait for the oohs and aahs as the flowers emerge in mid- to late summer.
ORIENTAL LILIES midsummer blooms
GLADIOLUS CALLIANTHUS tall, fragrant, white flowers with chocolate brown centers; late summer blooms
PINEAPPLE LILIES (Eucomis spp.) midsummer blooms
THREE-LEAFED CLOVER (Oxalis regnellii has green foliage, while O. triangularis has dark purple) won’t stop blooming until the first frost.
SPIDER LILIES (Hymenocallis cvs.) with their insect-like white flowers; midsummer blooms
Plant Container Maintenance Tips
1. Never use topsoil or garden soil in containers. In general, all planting mixes should be porous and free-draining. Potting soil is your best bet.
2. Place a piece of screening over the drainage hole(s) on the inside of pots to keep out insects such as earwigs and slugs.
3. If you’re a forgetful waterer, add a coir-based product such as SoilSponge to hold in moisture and extend the time between waterings. This particularly applies to containers exposed to hot, direct sunlight and those placed in windy locations.
4. Because containers need frequent watering, which leaches nutrients from the root zone, regular fertilizing-preferably with an all-purpose, water-soluble product-is necessary. Follow manufacturer’s directions as more is not necessarily better. If you plant herbs and vegetables and flowers and foliage plants, use organic fertilizer, such as fish emulsion.
5. Deadhead all flowering plants regularly to promote additional blooms; pinch back foliage plants to encourage bushier, more compact growth.
6. Check containers daily-twice daily during extreme periods of heat. Water thoroughly, but only when the soil feels dry to the touch two to three centimeters below the surface. It’s best to water in the morning.
Tips for Overwintering Container Plants
There’s nothing difficult about growing plants in containers. Give them good soil, food, and water. Keep in mind that plants growing in the ground are more protected from severe cold (and alternate freezing and thawing) than container plants. The real challenge is overwintering those potted plants so they can adorn your landscape in the spring.
As with any game plan, you need to understand your players. Some plants handle winter better than others, even if some plants are more trouble than they’re worth the extra work. How cold your winters are and what lengths you’re willing to go to protect your containers are also factors. Here are the methods you should consider for saving your plants for next spring.
Borderline-Hardy and Hardy Herbaceous Perennials
These plants usually dormant and die back in winter. Their roots sleep until it’s time for new growth next spring. Examples include daylilies, hostas, shasta daisies, heuchera, astilbe, and lady’s mantle. The goal is to provide a winter environment that’s within their hardiness zone.
After a couple of light frosts, it is critical to water your plants generously and adopt any of the following storage methods:
If the plant is at least one hardiness zone below your area and the pot is large, you might be able to leave as is. For example, herbaceous perennials in containers need to be hardy to Zone 4 or lower. And if you live in Zone 5, the likelihood of successfully overwintering the pot outdoors is high. A large box holds more soil, which helps insulate roots and keeps soil temperatures consistent. However, when the sun hits the sides of a container, especially a dark-colored one, alternate freezing, and thawing may trick your plant into thinking it’s spring and trigger early growth when it’s merely an unusually warm day in February.
For best results, store your borderline-hardy plants or those in small containers in an unheated shed or garage. Because the plants are dormant, light isn’t necessary, but regularly check to ensure the soil isn’t too dry. Reintroduce plants to regular growing conditions outdoors by gradually exposing containers to the elements for increasing periods when growth resumes in late winter or early spring.
Find a location, such as your vegetable garden, where you can sink the pot in the ground up to its rim so roots will be better protected from the winter cold. Cover the entire plant with about two inches (five centimeters) of winter mulch, such as shredded leaves or bark. Remove mulch in spring, and lift out your container.
Hardy and borderline-hardy deciduous shrubs, small trees, and vines
The stems, branches, and trunks of these plants persist over winter, but the leaves drop off in the fall. Examples include miniature roses, rose standards, Japanese maples, clematis, and dwarf lilacs. The goal is to keep plants dormant and within the range of winter temperatures, they would tolerate if grown in the garden.
Use large containers and plants that are at least two zones hardier than recommended for your area. These woody plants have above-ground branches that hold next year’s flower and leaf buds, making them more vulnerable to winter winds than herbaceous perennials.
For the best protection, store them in an unheated garage, against the warmest wall. If practical, place them in a garbage bag loosely filled with dry leaves for even more insulation (leave the top open for air circulation). Keep in a dark part of the garage; light may trigger growth too early. Once a month, check the soil to make sure it’s not bone-dry but do not overwater, as this could cause plants to rot or break dormancy.
Hardy Broad-Leafed and Needle Evergreens
These plants transpire (lose water) during winter, and when temperatures remain below freezing for long periods, root balls freeze solid. Water is unavailable to the plant, causing leaf damage or possibly death. Examples include English holly, boxwoods, English ivy, cedars, junipers, and yews. The goal is to keep them within their hardiness zone and prevent desiccation from winter winds.
Move pots to an area where they will be protected from intense winter sun and winds, and erect a burlap screen around them (don’t allow burlap to rest on foliage). Keep plants well-watered until freeze-up and frequently check throughout the winter to make sure soil is moist. Thorough watering before freezing temperatures and again in March and April, when the root balls are most prone to thawing—and drying out—is crucial.
Tip: Don’t forget to assess the winter hardiness of your pots. Soil-filled containers exposed to long-term freezing may expand and crack. Those made of earthenware, ceramic, and terracotta (unless designated as frost-resistant) are especially vulnerable; concrete, wood, plastic, and metal are more durable, but the last two materials offer little insulation for plant roots.
Tender Evergreens and Tropicals
These plants don’t require a period of dormancy. Examples include bay tree, rosemary, French tarragon, phormium, mandevilla, passionflower, and jasmine. The goal is to slow the growth of these plants to survive indoors during the winter and be put outside again once all danger of frost has passed.
A few weeks before fall frosts are expected, gradually introduce plants to indoor living by moving them inside for half a day, working up to a full day over a week or so. Don’t wait until nighttime temperatures are only slightly above freezing—plants may go into shock and drop leaves. Lightly prune, if desired. Place them in the sunniest location you have and water sparingly but regularly over the winter; high humidity helps, too. Don’t fertilize until just before you reintroduce them to outdoor living.
Tender tropicals that grow from tubers, corms, or bulbs
Examples include cannas, caladiums, and elephant’s ears. The goal is to store the tubers, so they neither rot from too much moisture nor dry out completely and die.
When frost kills back the plants’ tops, trim the stems to 10 to 15 centimeters from the base and gently dig up the tubers. Allow the tubers to dry for a day or two, store them in vermiculite or dry peat moss in a crate or box; place in a cool, dark area, such as a basement. (Check websites or gardening books for more detailed instructions for specific kinds of tubers, corms, and bulbs.)
Tender perennials most often are grown as annuals in cold climates.
First, consider whether it’s worth your time and effort to maintain these plants over the winter; most are easily acquired at a reasonable cost in the spring. Examples include geraniums, coleus, and impatiens. The goal is to continue growing these plants to use them again next year.
Trim back individually potted plants, and place on a cool, bright windowsill or under grow lights. Alternatively, take cuttings of your favorites and start new plants indoors. By spring, they will be large enough for containers.
Potted plants for high-rise living.
Balconies can be especially brutal for potted plants. Your best hope is to use large containers insulated on the inside with thick pieces of Styrofoam or fasten pieces outside during winter (bungee cords are suitable for this). If possible, move pots to a sheltered spot, out of wind and sun. Cluster them together with the hardiest plants on the outside and the most tender ones in the center. For extra protection, wrap the huddled pots in a large tarp, but leave the top open for air circulation.
How to build a Versailles planter?
While the Versailles planter’s origin is not entirely clear, many people assume the Versailles planter would have been first introduced in the elaborate palace gardens of Louis XIV. We believe that many of the ideas implemented at the palace were first developed by landscape architect André Le Nôtre for Louis XIV’s finance minister, Nicholas Fouquet. The minister wanted to erect the grandest château in France, full-on distinguished landscaping; Vaux-le-Vicomte is one of the earliest examples of the striking French baroque style. Unfortunately, Fouquet made the mistake of inviting his boss to the lavish housewarming party. Three weeks later, the king had the minister arrested for embezzlement. The château was confiscated, and the landscape architect was absorbed into royal service. Le Nôtre went on to design the palace’s geometric gardens and presumably a version of the planter seen here.
I built this Versailles planter out of cedar because of its affordability and weather-resistant qualities. Start by ripping (cutting parallel to the grain) and planing (smoothing) the posts and horizontal pieces to their final thickness of 2 3/4″. Your lumber supplier may offer this service or find a local woodworker to do the job.
Cut the posts to 21″ and put a 1/4″ chamfer on the tops using a miter saw set at a 45-degree angle. Saw the horizontals to size, then arrange all the 2 3/4″ pieces in their proper configuration so biscuit locations can be marked. Use offcuts as spacers to determine the lower horizontals’ height from the ground. The upper horizontals sit 1 5/16″ down from the top. Cut two #20 biscuit slots in each post and horizontal piece.
Dry fit the frame together, marking the inside intersections of the horizontal pieces on the posts.
Disassemble and add 1/2″ to the marks on the posts. These are the start and stop points of the 3/4″ grooves that accept the slats. The top and bottom horizontal pieces also get a 3/4″-wide and 1/2″-deep groove.
Cut the grooves with a 3/4″ straight cutter bit in a router with a fence attached.
Cut the slats to 12 3/4″ and chamfer the outside edges. Cut the four bottom corner blocks and attach them to the bottom horizontal pieces with biscuits, so they’re flush to the top of the bottom horizontals.
Dry fit the planter, minus the slats, then clamp (don’t glue). Mark a centerline on the 1 5/8″-wide crosspieces. Hold each crosspiece on the outside of the planter. Align the centerline with the inside corners of the posts and horizontals, scribe (mark) the angle, and cut to size.
Before gluing, give all pieces a thorough sanding with 120-grit sandpaper. Use an exterior glue on the biscuit joints and all the surfaces that meet, except the slats, which need to expand with humidity changes.
Fit the crosspieces in place, so one overlaps the other, scribe lines where the outer piece covers the inner one, remove, and cut away the overlap. You will now have three components that form the “X”; glue and nail into the posts and horizontals.
The slats of random widths sit on top of the horizontal and corner pieces; they are spaced about 1/8″ apart to allow for drainage. The outer slats get a 1″ x 1″ notch, so they fit around the posts.
The finials truly do finish the piece. I used 2 1/2″ wooden balls available at craft supply stores. They have a flat bottom complete with a 3/16″ hole. Mark, the center of the top of each cedar post, then drill and attach the ball with a dowel and exterior glue.
If your planter will be shifted around a lot, drill a larger hole in the ball and post, and fit it with the corresponding dowel for added strength.
Fill any knotholes or imperfections with exterior wood filler; allow to dry, then prime the planter. A light sanding with 220-grit sandpaper will smooth the raised grain created by the primer; remove any dust with a tack cloth and vacuum, and then apply two exterior acrylic paint coats.
Now your plant has a home fit for a king. Just don’t show it to your boss.