By Glenn Withey
my partner and I enjoy renovating garden beds, it may take two or three years
before a design concept comes to fruition. With container gardening, results
come a lot quicker. Gardening in containers allows you to create a totally
different look each year, if you choose.
the most important rule is having a quality, aesthetically pleasing container.
If an unplanted flowerpot is homely, it will most likely remain homely when
planted. Beautiful pots can be expensive, but you can take years to build a
nice collection, one piece at a time.
Another consideration: is the ceramic container
frost-proof? As a general rule, the higher the pot’s firing temperature, the better
are its chances of long-term survival. That said, on occasion a pot may crack
if waterlogged and frozen.
containers can be quite nice, but offer no insulating value—roots can burn in
the summer, and plants freeze even more quickly in winter. This problem can be
alleviated, to a degree, by lining the pot with a firm insulation material.
Rust stains from steel containers may also be a problem, so be aware when
siting them on a patio or deck. There are some very handsome fiberglass/resin
pots around, but we’ve only seen a few good-looking plastic pots.
it comes to the container’s size, there is another rule of thumb: try to use as
large a pot as possible (so long as it looks good). The larger the container
is, the slower it will be to dry out.Also, in a windy site, a taller pot with
say, a Japanese maple, will have a greater chance of toppling over, versus a
short, wide container with the same plant.
Try to group containers
together in some odd number. If you have a symmetrical garden layout it’s fine
to keep them so but otherwise if you have, say, four pots, think about creating
a group of three with the last one offset. Stand-alone containers work, if of
good quality. I usually keep pots below the height of railings and windows if
they are in front of them, but that’s not a fast rule—every situation needs its
As the saying goes,
“Garbage in, garbage out.” This applies to your soil, too. The most expensive
brand may not be the best, even less likely will the cheapest. If you have a
brand that works well for you, stick with it. When trying a new soil, plant one
container and see how the plants perform.
to aggressively feed containers with both time-release and liquid fertilizer.
Over the years, I’ve gotten in the habit of using less with good results.
When planting, add a
time-release fertilizer and skip the weekly liquid feedings. Come August, or
when the planting begins to flag, use some water-soluble fertilizer to pep
Certain plants, such as
brugmansia, are food hogs. This plant is difficult to overfeed. I still
remember watching one being potted up, and my friend put in a good pound of
time-release fertilizer. The plant loved it…
In my early days I relied on annuals. Nowadays, I use at
least half evergreen plants, as they offer year-round interest. If there’s a
suitable spot in the ground when I take the planting apart, I will reuse the
Since day one I’ve always included some fragrant plants. I
once planted lilies in containers by my entry door. Wonderfully fragrant, they
thrilled me. Then they went out of flower and summer wasn’t even half over. By
the end of summer I’d learned my lesson. Most floral “show-stopper” plants are
not very appealing out of flower. Nowadays I select plants that earn their
keep. Good foliage and structure is most important, followed by how long a
plant will flower.
using shrubs or small trees, remember that if you want to remove a plant
(intact) at some future date, the opening of the pot needs to be wider than its
middle or bottom. This may seem self evident, but often containers flair
slightly inward, which results in much swearing when trying to remove said
Root hardiness is critical
when selecting permanent plants. Containers freeze solid long before the ground
does. As a general rule, if a plant is borderline hardy here in the ground,
don’t expect it to thrive long-term in a pot. Of course there are exceptions to
this rule, but spending $100 on a conifer is likely a wiser choice than spending
the same amount on a phormium.
I love simple, graphic plantings. Three beautifully clipped, dome-shaped
boxwoods are often more pleasing to the eye than an eclectic mix of plants. Of
course one is entitled to change one’s mind, and I might say the opposite next
I create mixed containers, I generally don’t cram as many plants in as I used
to. Twenty years ago, I might’ve smooshed ten different species into one pot.
Now, I am much more likely to put in three different species, or even a single
kind of plant per pot, with five or seven pots grouped together to create a
you want to mix evergreens with annual color, be careful how you place
rambunctious annuals. While boxwood and yew can take considerable shading, many
conifers will resent it and dead chunks may appear. Also, planting a four-inch
annual amongst the roots of a well-established permanent plant could be tricky
work. Unless it is quite tough and vigorous it will need more TLC in order to
compete. A container where all the plants are of relatively equal size and the
“playing field” is more even will increase the odds of a beautiful outcome.
Plan on either installing a
drip system or being there throughout the summer, hand-watering. At the Dunn
Gardens, where I work, I hand water. Summer is the one time of the year when I
want to be there, enjoying the best of what the region has to offer.
For a lot of people, drip
irrigation is the choice. Be aware that once a system has been installed, it
will need maintenance. Emitter lines will plug, so check the system several
times a year.
Once a pot has dried out
and the soil has pulled away from the edge, it takes diligence to rehydrate it.
Repeated soakings are in order, especially with a peat-based mix.
Conversely, keep the
container’s drain holes clear. On more than one occasion I’ve had plants almost
drown. Roots can grow in or out through the drain holes and plug them.
Train your eye to notice
the color of foliage—leaves will often show stress with a slight graying before
it’s too late to save the plant, but you need to act fast. The beauty is—if you
lose the plants, at least you still have the container to replant!
Remember to maintain the
plantings weekly. Even supermodels look dreadful if they aren’t cleaned,
groomed and kept healthy. NWGN