Container Gardening

First Principles ? The Big Mistake ? Choosing and Filling a Container ? Plant Suggestion

When I look around my garden I realize what?s unnerving this year: my containers. They are pathetic, half haven?t been filled leaving a serious gap in the look of the garden. These things take time and consideration-it?s not like the old days of nothing but red geraniums or white petunias on the back stoop. My idea of a really good time is to cruise around the neighbourhood and pinch ideas from containers on display around houses and, especially, in good garden shops. Creative stealing has always been an honourable part of gardening. Horticultural Design and Via Verde are two such productive places in Toronto. Hort Design headed by Michael Renaud is an established institution and Via Verde is brand new one rising out of the ashes left by the closing of Cruickshank?s which left people aghast last year. Here the intrepid owners Annette McCoubrey, Linda Ledgett along with partners Nancy Grepe and Kathryn Bustin are with us again doing new and fresh things. My patrolling of the Rialto has led to a mini-revolution in my own container gardening and I hope will do the same for you.

First Principles

  • Don?t think just one season. Pots can be put out early with bulbs and perennials (hyacinths and hellebores; narcissus and hostas) and late (grasses for sure), along with all the usual favourite plants for summer.
  • One thing that bugs me completely is seeing a container jammed with plants, every one different. It turns into visual mush. These experts emphasize overplanting to begin with but using no more than three kinds of plants. Just stuff them in making sure you have the edges covered up to soften them. When the plants get too big you can always move some out.
  • Study every detail: the location of the planter, the container itself, its shape is especially important. Make sure it fits properly and this will help dictate what to put in it. A tall thin house needs a different arrangement from a wide sprawling house.
  • Consider the background, the colour of your house, the railings (formal, informal) Blend with it or make the container complementary but don?t let it clash. If you can (and this might have to be custom finished) find containers that match the brick or the house.
  • Sounds odd to have to say this but?make sure you have plants with the same light needs together in one container. Mixing up shade and sun loving plants will mean that half your arrangement will die.
  • Don?t make any combination too upright or too sprawly: get a good mix of both. If you use an upright plant, make sure it looks very sculptural. Phormium, for instance, demands something equally formal and interesting below rather than fluffy plants around it.
  • Take into account how you?ll see the containers: only on the way into the house? Make sure you plant for scent. On the balcony: where will you be sitting inside and how will it complement the room you are in. On the deck: don?t let them overwhelm your seating area or fall into your food.
  • Be brutal: if a combination doesn?t work out, chuck it and start again. Removing things will always help if you?ve headed in the wrong direction. The simpler the better.

The Big Mistake

Ditzy little containers. Buy larger than you think you need, advise Via Verde, chances are you?ve miscalculated what it will look like in the space you?ve got. Having little pots dotted about means you won?t get a splashy effect and they look uncomfortable. Like all other forms of gardening, scale is incredibly important and if you use little containers you won?t do justice to the space. They recommend measuring the space first, then look for as few containers to fill it as possible. Their analogy: if you have a hundred dollars, buy one pot rather than two for $50. Hort Design cautions not to use a huge container with a little plant in it; or a giant plant in a little container. They will grow but a fuchsia standard in a little urn will dry out quickly and two weeks later is dead. Hort Design?s bete noir is seeing a huge topiary on a plinth and slightly cock-eyed. Don?t put big things on pedestals if they don?t need the height. Always have topiary dead straight.

Choosing and Filling a Container

Choosing the right container is fraught with controversy: all the same, all different? Everyone has a opinion. It?s not like decorating your living room where eclecticism is everything. With containers you want some consistency. I?ve always had a clutter of container styles and I?ve always hated the way my blue and white mix didn?t quite work with the terra cotta and the concrete. For good reason-it has no articulation.

  • Keep it simple, says Via Verde: formal with formal, casual with casual. One element could, for instance, be the leitmotif: different mediums but with a woven pattern to keep them hanging together. Hort Design believes in being consistent: all the same terra cotta, cast iron. Failing this, have the same colours and mix different styles. For instance, stone and cast iron are fine if colors are the same tone.
  • Speaking of colour don?t forget the house: it?s a mistake not to take in just what this background is and don?t let your container planting fight against it because the house always wins.
  • The medium is definitely the message: cast iron in an informal setting isn?t as compelling as it is in a formal one; just as a terra cotta might now look great in a formal setting.
  • Time: don?t kid yourself about this. If you?ve got an hour a week, or you?ll be away all summer, make sure that this is taken into consideration when you choose plants. If you sweep through with a watering can once a week don?t plant things that need watering twice a day. Don?t plant annuals needing constant deadheading if you don?t want to spend the time fussing about. Be sure you?re interesting in looking after your containers otherwise get low-maintenance perennials that won?t take a lot of time.

Plant Suggestions

  • Via Verde prefers texture to brilliant blooms and that?s something I?d go along with. Foliage plants always look good in a container and are generally easier to care for since they?ll require little or no deadheading. Concentrate on leaf sizes (large vs small); green and brown and purple foliage. For instance choose from this group: Campanula ?Blue Clips?, scaveola (also blue), heliotrope and purple basil along with variegated helichrysum and Lady?s Mantle (Alchemilla mollis).
  • Tone on Tone is another the Via Verde concepts that works beautifully with the following plants which will give you a sensuous wallop of texture as well as scent: santolina, lavender (how about the new variegated form), teucrium, helichrysum.
  • They also like lavender standards underplanted with heliotrope. Putting heliotrope with a rose extends the containers usefulness simply because heliotrope has such a lovely scent.?
  • Horticultural Designs veers toward enchanting combinations of ferns, grasses and tropicals: Pennistum rubrum or blue lyme grass mixed in with a leafy chartreuse plant such as Neonpothos (it?s in the philodendron family and has a heart-shaped leaf); Muehlenbekia has a dark brown stem with a little round leaf. These combinations are so subtle and low maintenance it?s possible to go away for a weekend without worry. The Muhlenbekia can twine around forms for topiary or be used as a cascader. They also use sword ferns in their combinations.
  • I?m crazy about lime green and burgundy foliage and will look for any combination of the two with coleus is at the top of the list. Coleus just gets better and stronger as a plant with sensational new forms coming out each year. And I?ve always got to have a pot of the biggest rosemary I can find (and hope to winter over indoors) both for cooking and smell put that with the dark purple of Cryptotania japonica and you?ve got a dazzler.
  • Lots of Hostas. These are ironclad plants, absolutely great for containers. Since they come in so many sizes and colours you can afford to have a collection of them ranging from pale blue, to stripey greens and yellows to pure gold. I like to use them alone in a container. So a small one in a small container seems to me to be the best if you?re showing it off. But take size seriously some of the hostas can get huge. H. ?Krossa Regale? is stunning and all the blue forms-including ?Halcyon? and0?-are equally effective.
  • All of us agree: at least one container of sempervivums: the classic hens-and-chicks, is a must. You can?t have too many semps and if you have a location that?s sunny and windy these are the answer to your problems. They come in colours ranging from deep red to brilliant almost yellow-green, silver gray, webbed and they all deserve attention. They combine superbly with echeverrias and other succulents.
  • I?m trying every perennial I can, especially euphorbias and hellebores, to see how well they do containers and how they winter over stored in a cold shed. Japanese maples look incredibly beautiful in containers. I have an Acer palmatum ?Villa Tranto? so gorgeous everyone who visits stop in awe in front of it. There are new forms of Japanese maple becoming available and many them are quite small. Make sure you have a place to replant in the garden in the autumn or storage in autumn. They?ll croak in most part of Canada. See below.
  • I was so excited about putting perennials in containers I almost forgot how many good annuals have come to us recently. Bacopa is a lovely small-leaf plant with masses of white flowers. B. ?Olympic Gold? has brilliant yellow leaves; and Bacopa lenagera ?Variegata? has variegated leaves that are perfect to stretch imagination to pick up either colour in coleus or some of the other foliage plants.
  • Coleus has so many new forms on the market I can?t keep up with them any more. Here?s where you can get the burgundy and lime colours that are so wonderful. They look good with almost everything.

Balcony and rooftop gardeners don?t have to worry about the weight of most containers unless they are planning on trees and large shrubs. Most containers filled don?t weigh much more than a small child. With trees and huge shrubs, make sure you know what your building code demands. And that there?s a service elevator to bring up material, soil and the plants.

  • Fibreglass containers are ideal for balconies and rooftops. They are much more sophisticated these days (and not that cheap either) and can stay out all winter. With any large container try it out empty and once you?ve decided on the final spot make sure it?s on chocks to keep it off cement floors. Then proceed:
    • Make sure the container has a hole in the bottom. If not, get one drilled to make sure there is some form of drainage.
    • Put something in the bottom to keep soil from running out, you will have to water heavily in most cases. I picked up this tip: use all the leftover plastic 6-pack containers turned upside down. This will take up volume especially in large containers and provide drainage. Otherwise use a shard of terra cotta, piece of landscape cloth or layer of sticks.
    • Add the special soil mix. There are several sources of potting soil (don?t use garden soil). This is a a water retentive soilless soil mix. Via Verde recommends using Seagrow a potting soil which contains all the nutrients needed. It doesn?t have to be replenished every year which is crucial if you want to keep your containers in place all winter. It retains moisture well. 31L/$10.95 isn?t cheap but I like the idea that you don?t have to keep bumping it up which you should do with ordinary potting soil.
    • Place the plant so that it?s an inch and a half or so below the top of the pot. Experiment by moving the plants around to get a pleasing arrangement.
    • Water thoroughly and keep it watered on a regular basis twice a day if they are exposed to sun and wind.
  • Winterizing: If you plant to leave containers in situ, place them on chocks, trivets or bricks to keep them off cement floors or wooden decks. This will help with drainage and keep them from getting frozen. To overwinter perennials, make sure you have a frost proof container, line it with a thin sheet of Styrofoam. When the sun hits it in winter it won?t thaw. It?s the freeze-thaw action that?s a killer for container plants.

Here?s what I ended up doing with my own containers: I clustered the ones with the same medium together in different parts of the garden. I?m keeping only a few of the largest and getting rid of the rest. All the little pots are now used in a line under a bench where they are charming and decorative. I?m going to try to control the urge to buy any more containers of any kind unless they are frost-proof and I can leave them outside all winter. The final caveat about containers is don?t ever let them get out of context. They should relate to your garden if you have one; and if you don?t, well, this is a wonderful way to develop your palette and learn about foliage and textures you?ll end up loving.