Perhaps the most asked about plant in our garden right now is this purple leaved silk tree or mimosa, with it’s stunning chocolate purple fernlike foliage. The followup question is often, “but is it hardy” to which we answer, “yes, but…”. (Recommended hardiness zones are zones (6b) 7-10, and our garden is definitely zone 6a.)
This is the scoop based on our experience. Albizia julibrissin ‘Summer Chocolate’ is a fast growing ornamental tree or large shrub, introduced to the US market roughly 10 years ago. True, it is less hardy than the more common green leaved forms. In 2005, our first attempt to establish this tree failed. We didn’t site it well. We planted ‘Summer Chocolate’ in a spot where we thought it would look outstanding, but alas, it was the lowest spot on our property and the soil remains too wet there over the winter. Initially we were resigned to growing it as a container subject, but were reminded by the old adage: if a plant doesn’t grow well in one spot, try another, and then another.
Good drainage usually is key in wintering over borderline hardy plants. We planted the next specimen in well drained soil in front of a south facing stone wall, and are now enjoying this beauty for the 3rd year in a row. It did get some die back after the winter of 2009-2010, but broke growth along the lower trunk and quickly grew to 6′ that year. We won’t expect it to reach full height or width, and don’t really care. Tropical appearing chocolate colored foliage with a shrublike habit suits us just fine.
Those of you in milder winter areas (zones 7-10) can expect this tree to reach 20′ in stature and spread, with silky pink puffs of flowers in summer. Gardeners in zones colder than 6 might consider growing ‘Summer Chocolate’ as a stunning container specimen. The plant, pot and all, can easily be moved into an unheated garage or other protected spot once it goes dormant in late autumn.
As tempting as Black Friday Shopping is (or isn’t), why not plan an alternative activity on the day after Thankgsiving. Have a thermos with hot cider ready and invite a couple of friends or family members to wander about your garden to gather greens and branches for wreaths and decorating. You’re bound to find a varied selection of evergreens and branches, bare but structural, or decorated with berries and seed pods.
Don’t restrict yourself to the traditional selections…Holly, Boxwood and Pine. You’ll be surprised how well unexpected clippings work. Junipers provide blue-gray foliage and often have attractive blue fruit. Chamaecyparis offer a wonderful array of foliage colors ranging from gold through amber, bronze and dark green, and I love clipping the branches that are adorned with artful cones. Consider twigs with interesting bark or an attractive zig zag habit which will twinkle when coated with morning frosts. Red and gold twig dogwoods offer colorful linear accents, while birch branches can often be found dripping with catkins.
Word of caution: When cutting for arrangements, first be sure you observe how your pruning will effect the shape of the plant. Stand back and view the subject from different angles. You can prune/improve the shape of the shrub and have branches for arranging at the same time.
Display these cut branches in an outdoor container ensemble right away or wait. The smaller cuttings need not go to waste; they can be used to construct a wreath for your door. If you?re not quite ready to decorate, the greens and cut branches can be stored in a cool space until needed. Indoor arrangements created now will become quite brittle and shatter by Christmas, so you may want to wait or plan to do two sets of arrangements, one for now and one for later.
Here’s an easy ensemble that gets its color from foliage and fruit. These five plant selections will fill a 12″ tall tom pot easily. The ingredients are Pennisetum s. ‘Rubrum’ for height and movement, Heuchera villosa ‘Caramel’for body, and Hedera ‘Amber Waves’, a golden leaved ivy that trails beautifully and will take temperatures into the low 20’s. What makes this collection “caliente”are the adorable ornamental peppers. We tried two new varieties this season, ‘Sangria’ and ‘Prairie Fire’, which have been producing an endless supply of round and pointy peppers in shades of creamy yellow, orange, red and purple. Oh yes, they are edible, but very very hot.
Pennisetum with Heuchera ‘Caramel’, Cuphea and Calibrachoa
One of the pleasures of container gardening is that you can create fresh arrangements to complement each season?s landscape. The colors of Fall Chrysanthemums have been selected for just this effect, but isn?t it dull to limit yourself to just a single plant? Consider the wide selection of cool season “annuals” that are at their prime in September and October, offering at least 6-8 weeks of color. There are ornamental peppers, salvias, grasses, million bells, abutilons and cigar plants, just to name a few. Don’t forget the perennials with outstanding foliage, like Heuchera ‘Caramel’ and Autumn Fern (Dryopteris erythrosora) which add contrast and can later be transplanted into the garden for next year?s display. And then there are shrubs with fall interest, such as Hydrangea paniculata ‘Little Lime’ (aging blossoms), Cornus ‘Arctic Sun’ , and Ilex verticillata (Winterberry), which will add height and weight to bigger pots. Here are two more tips for pulling it all together.
First, remember to select a variety of bold and fine textures. The bold punch of a large leaved Heuchera, or Ornamental Cabbage adds much needed weight and contrast. This is the season of ripening fruit, so take advantage of the ever widening selection of Ornamental Peppers or consider shrubs with a nice berry set, such as Viburnum or Winterberry. Grasses add height and movement, and you can always use hardy grasses besides the more showy annual Pennisetum.
Second point: The growing season is slowing down here in the northeast, so start with larger plants and/or use more plants to fill up the container right away. There is not a lot of time now for plants to put on added growth. Think of assembling your container as you would a flower arrangement, except that this composition will last for weeks as opposed to just a few days.
Begonia, Pilea and Tahitian Bridal Veil
Again, it is so much about the foliage. The angel wing leaves of Begonia ‘Sinbad’ are really a soft celadon green veined in rose, but have a silvery cast. On close inspection, the silvery effect is due to the pebbly texture formed by the tiny raised white leaf segments. Simple, sweet pink flowers dangle from the leaf axils. For filler, the tiny white variegated foliage of little Pilea, commonly called artillery fern, creates a frothy effect beneath the bolder leaves of ‘Sinbad’ and the casual abandon of Gibasis geniculata , also known as Tahitian Bridal Veil, with its two tone green/purple foliage and white baby?s breath blossoms finish off the combination.
Culturally, use a well drained potting soil, amended with Osmocote. Begonias do not want to live in soggy soil, so monitor watering by allowing the soil to dry out a bit. This ensemble would enjoy morning or filtered light, and would be a suitable arrangement for a covered porch, where the minimal watering needs can be monitored.
Remember when Coleus was disdained by “serious gardeners” just 20 years ago? Until recently Succulents also seemed to get a bum rap. Perhaps it was because of the silly little dish gardens offered in discount stores, featuring a ubiquitous strawflower glued onto a poor little cactus. We decided quite some time ago to treat succulents with dignity. Their foliage offers an array of subtle and strong desert colors and textures which inspire us with ideas for endless combinations. And, they couldn’t be easier to take care of– perfect container plans for the summer weekend home, since so little water is required.
Begin your ensemble by selecting a handsome container. Break the rules…why not use a fancy bowl or urn that you would use for traditional annuals? Shallow pots are always fine and suitable, but deeper pots can certainly be used if you fill them with a very sandy, fast draining soil. Do not use a moisture retentive peaty potting mix, for it will easily become water logged if we have extended wet weather. You can use a light dose of fertilizer in your soil mix, but don’t over do it.
Select a variety of foliage shapes and plant forms, such as the rosettes of Echeveria, the trailing stems of Delosperma and the fine texture of tiny Sedum. We always find that packing the container with plants gives immediate gratification, and the plants will not suffer as they require little nutrition. Early autumn will bring changes to your composition, as the fall foliage colors intensify and many succulents begin to flower. Before a freeze, bring your succulents indoors. They winter over easily on a sunny window sill.
This easy care combination, which will be very happy in a spot that receives 4-6 hours of sun, includes Fuchsia ‘Gartenmeister’ complimented by multihued Calibrachoa ‘Tequila Sunrise’, Helichrysum ‘Limelight’ for light contrast, and Coleus ‘Dipt in Wine’ which picks up the colors of the other 3 candidates.
The Fuchsia and Calibrachoa (Million Bells) will lure hummingbirds and bloom endlessly. Should the Helichrysum (Licorice Plant) or Calibrachoa exceed their bounds with vigorous growth, just clip back. Plant this grouping in a good quality potting mix amended with compost or PlantTone, and Osmocote. In addition to fertilizer in the mix, we always recommend liquid feeding your containers every 1-2 weeks with a balanced plant food, such as Dyna Gro.
A classic combination for a sunny spot. We’ve combined our favorite Pelargonium sidoides with a new heat tolerant pale pink Marguerite, Argyranthemum ‘Pink Reflection’, silvery Centaurea gymnocarpa ‘Colchester White’ and Dichondra ‘Silver Falls’ and a compact selection of Gaura ‘Belize‘, with wine tinted foliage and wine/pink blossoms that dance on 18-24″ stems all summer.
Focus on foliage
Container Gardening is a summer long activity. Plants grow quickly, and it is only a matter of week or two before a new grouping “knits” together. You can move, mix and match pots all season long.
We’d like to pass on basic tips for successful container plantings.
1. Select plants that all like similar growing conditions (i.e…sun, shade, dry soil, moist soil).
2. Use a good quality potting soil amended with an organic plant food like Garden Tone and/or Osmocote time release fertilizer.
3. Remember to select/focus on plants with interesting foliage, which will add color and texture without the need of constant flower deadheading. Think of the flowering plant choices as the “accents”.
4. Finally, liquid feed with Dyna Grow or Seaweed/Fish Emulsion on a regular basis, which will replace the nutrients leached out of your pots from frequent watering.