Wednesday, November 10, 2010

PUSHING POTS

     For Fitzgeralds Gardening, November is when container change-outs for winter swing into high gear. Tim and I refill between 60 and 70 pots and windowboxes for about ten clients, and another seven to ten at our own house. Since practice makes perfect, we’ve gotten quite good at it over the years. Want to know some of our secrets?
     Well, you could check out Carolina Gardener’s November/December issue, where the lead article (that I wrote) covers the subject as thoroughly as possible in 800 words. Because my first attempt at adding links went so well, I’ve added one for Carolina Gardener. Hard copies may be found at independent booksellers in North and South Carolina, Virginia and Georgia, and at garden centers in those areas.
     OR, you could keep reading here, where I recapitulate and enlarge upon the subject.

First Things First
      As is usual in the gardening world, a few details need to be sorted before we get to plant choices.
  
     When deciding where to place winter containers, consider things like sun, wind, and water. Potted plants’ roots lack the protection being in the ground provides, so they suffer more from temperature extremes, desiccating winds, and dry soil. Brick and stone walls (especially light-colored ones) that face west or south retain more of the heat of the day than dark-colored vinyl, wood and hardy-plank. Know what direction the prevailing wind comes from, how it crosses your property, and what obstacles—trees, hedges, other structures—affect it. Make sure the pots have water, although not as much as during the summer. Are they likely to benefit from rainfall? It’s best to test the dirt with your finger for moisture: just like indoor houseplants, many outdoor cold-weather containers drown. (Trust me on this: I’m an expert at killing houseplants.)
     Next, choose your container well. In general, anything that drains readily and can stand up to your weather works fine. Be aware that plastic and unglazed terra cotta pots may crack and flake. Glazed ceramic, fiberglass, and cocomat-lined wrought iron hayracks and baskets fare better.
     Here in the mild-wintered Southeast, if you want to use clay pots outside during the winter, keep the following considerations in mind.
  • Glazed ceramics hold up better than unglazed terra-cotta. Why? Pots crack because of freeze-thaw cycles: glazes keep moisture from permeating the clay, making it less susceptible to expansions and contractions.
  • Not all pottery is created equal. Italian, Portuguese, Vietnamese and Malaysian clays form strong molecular bonds that fire smooth. On the other hand, Mexican clay has proportionately more sand, resulting in finished pieces with that lovely grainy texture. This is not a problem in Mexico or the dry American Southwest, but for the rest of us, winter can cause Mexican pots to crumble.
     One last thing: the primary secret to drop-dead-gorgeous pots at any season is to cram the plants in. While exact numbers depend on individual plants’ shoot and root vigor, plan for:
·         15 3- to 4-inch pots, or 5 six-packs per 14" diameter pot;
·         18 3- to 4-inch pots, or 6 six-packs per 16" diameter pot;
·         18 3- to 4-inch pots, or 6 six-packs per 30" long by 6" wide hayrack;
·         21 3- to 4-inch pots, or 7 six-packs per 36" long and 6" wide hayrack;
·         24 3- to 4-inch pots, or 8 six-packs per 42" long and 6" wide hayrack.
 
Mixed violas and
'Snow Princess' alyssum spill
out of a 36" hayrack

 A one-gallon pot equals 4 3- to 4-inch pots, or 1½ six-packs, by the way.

Annuals are very forgiving of crowding, since their only reason for being is to set seed for next year. Perennials require more root-room, especially if you plan to put them in the ground after their stint in a container.  

Freeze-hardy Flowers
      Now we can talk plants. Pansies and their relatives (Viola x wittrockiana) serve as anchors for many cold-weather containers in mild-winter areas. The small-flowered violas like the Penny, Sorbet and Endurio series and the cheerful Johnny-jump-ups (V. tricolor) bloom more profusely than their larger and blowsier cousins, the pansies. As an added bonus, violas never require deadheading. Unfortunately, all members of the viola family are deer candy.
     Other cold-hardy (to about 20°F) reliables include:

'Endurio Violet' &  'Penny Orange' violas
and 'Easter Basket' alyssum
looked so good all season
the neighbor asked if they were fake

  •  Alyssum (Lobularia maritima)—alas, the floriferous new hybrid ‘Snow Princess’ crashed here after several nights at or near 20°F. It survived a shearing to rebloom when the temperatures moderate;
  • Snapdragons (Antirrhinum majus)—although blooming stops after the first hard frost, they bracket the season with carnival colors and provide height and a green backdrop for violas;
  • Perennial pinks (Dianthus barbatus) flaunt their red, pink, white and bicolor blooms through all but the coldest months. 
As it happens, not that many flowering plants fill the bill for winter containers, but don’t give up yet—we’ve just scratched the surface of possibilities.

Don’t Forget Foliage
     Incorporating evergreen plants with interesting or colorful foliage makes up for gaps in flowering. You might want to try:
·        Ornamental cabbages, kales and chards (Brassica spp. cvv.)—winter foliage stalwarts;
·        Low-growing bugleweed (Ajuga reptans cvv.) forms dense mats in variegated, chocolate, or purple-ish shades, like ‘Caitlin’s Giant’ and ‘Burgundy Glow’;
·        Trailing green-and-silver dead-nettle (Lamium maculatum cvv.) produces pink, white or purple flowers in late winter;
·        Curly-leaved parsley (Petroselinum crispum) adds bright green—and edible!—accents;
·        Dainty variegated lemon or silver thyme (Thymus x citriodorus) and mother-of–thyme (T. vulgaris) provide fine-textured underplantings for upright plants;
·        Dense plantings of dark green or variegated English ivies (Hedera helix) replace those crunchy Boston ferns hanging on your porch;
·        Small ornamental grasses—golden sweet flag (Acorus gramineus ‘Ogon’), thin-bladed sedges (Carex buchananii, C. comans ‘Frosted Curls,’ C. flagellifera ‘Toffee Twist’), breeze grass (Lomandra longifolia), and rushes (Juncus effusus ‘Wild Rumpus’ or ‘Will Fleming’— provide strong verticals; 
·         Hens-and-chicks (Sempervivum tectorum) cultivars come in a range of tints, all cold-hardy to Zone 3, which includes northern Minnesota and all of Maine.

Except for the brassicas, none of these selections ranks high on Bambi’s forage list.

Super Shrubs
      One- and three-gallon upright shrubs make strong design anchors, either alone or with other plants. Broadleaf choices include camellia (C. japonica, C. sasanqua), dwarf nandinas (N. domestica ‘Firepower’ or ‘Moonbay’), boxwood (Buxus sempervirens or B. microphylla var. koreana) and little-leaved hollies (Ilex crenata ‘Soft Touch,’ Ilex vomitoria ‘Bordeaux’ or ‘Schillings Dwarf’). Conifers like dwarf Alberta or Colorado blue spruce (Picea glauca var. albertiana, P. pungens f. glauca), juniper (Juniperus spp.), arborvitae (Thuja occidentalis) or false cypress (Chamaecyparis spp.) work well as container focal points. Combining several different small conifers in one container makes an attractive and deer-resistant dish garden.

Harbingers of Spring
     Layering small bulbs into winter containers gives a late-winter color burst that also heralds spring. Tuck in 20 to 30 early small daffodils (Narcissus obvallaris, Quail,’ ‘Tête-à-Tête,’ ‘Canaliculatus’); crocuses (C. tommasinianus are least attractive to squirrels); snowdrops (Galanthus elwesii, G. nivalis); and/or crested iris (Iris cristata). Where winters are colder than the coast’s, add squill (Scilla sibirica) and grape hyacinth (Muscari spp.) to the list.          

The plantless holiday planter

It Doesn’t Have to Be a Plant 
  
       But who ever said you have to use plants? Decorate your containers for the holidays with big red bows, clusters of ornaments and garland, but don’t let your imagination stop there. Pine cones, either spray-painted or au naturel, look great all winter erupting out of a pot. Fill windowboxes with Christmas-tree balls of every color and size to carry through to spring (look for ornaments labeled for outdoor use: the colors on the indoor ones chip off after a couple of months). Dried ornamental grass plumes, corkscrew willow twigs, or sprays of berries—real or artificial—bound into sheaves with bright ribbons add height and drama.
           
Sometimes a Pot Is Just a Pot
     To me, one of the most striking aspect of winter is its unclutteredness. In the same way we find beauty in leafless tree limbs, pretty pots standing empty gracefully echo winter’s simplicity.
A winter container vignette

     Thanks for dropping in. Keep warm.
                                                                            Kathy 

 P.S.--If you're reading this from New Zealand, would you log a comment to tell me where you're from? I seriously considered emigrating years ago, but was already over 40, and 'way too poor, worse luck. But I loved your country, particularly Ahipara and Te Anau, Dunedin and that mountain on the west coast of the North Island whose name escapes me at the moment.