Rule
1. It's your garden. Use any container you want or can find.
Attractive glazed pottery is readily and fairly cheaply available. Clay
and terracotta pots look good anywhere. There is nothing to stop you
from using whatever comes to hand. Plastic pots, half barrels, old water
tanks, oil drums, large tin cans, old boots, polystyrene fish boxes - if
they hold container soil you can adapt them. Just make sure the
container is large enough to hold a good volume of soil (the bigger the
better) and has a drainage hole or holes so that excess water can
escape.
Rule
2. There few plants that cannot be grown in a suitable size container.
This includes trees and shrubs, climbers, perennials, ferns and bulbs as
well as the more commonly grown annuals and tender perennials. Don't
limit yourself to a few common annuals. Experiment. If all you have is a
shady spot then use containers full of shade lovers. Ferns, hostas,
camellias, pieris, heucheras and many others can provide foliage
interest, while flowering interest can come from fuchsias, lilies and
impatiens. If your container garden is sunny but windswept use plants
that thrive in these conditions. Hebes, cistus, cordyline, pittosporum
and many others will all add decoration and provide a shelterbelt behind
which more delicate plants can grow. If you need height try climbers.
Small flowered clematis, morning glory, the less vigorous climbing
roses, nasturtiums and many others grow well in containers. If your
container area is really warm and sheltered then try tender plants.
Sub-tropical plants like bougainvillea, brugmansia, oleander, tibouchina
and hibiscus will thrive outside in warm summer areas - although they
will need winter protection in all but the most favoured sites.
Rule
3. Once you decide to grow plants in containers you must never neglect
them. Their roots can't escape and seek food or moisture, and
the top growth can't travel long distances to seek light. This means
that you must give them the right conditions in the first place and
continue to provide these throughout the life of the pot.
About
container soil. Good container soil should be free draining
but also hold moisture. It should also suit the pH requirements of the
plants. Rhododendrons, most heathers, camellias, pieris, skimmia, citrus
and many others must have acid soil. You can buy this at the local
garden centre. Others benefit from acid soils. Hydrangeas will never be
blue unless the soil pH is below 6. They will grow happily in more
alkaline conditions but will only come pink or red.
Use a variety of
container soils depending on the requirements of the plants. Most will
be fine with a 50:50 mix of soil based and organic potting soil. The
soil provides weight, a reservoir of trace minerals, and an environment
in which beneficial soil organisms flourish. The organic component
provides water-holding materials and also improves the drainage. For
acid requiring plants, use a similar mix in acid container soils. For
plants that need free drainage I add very coarse sand or fine gravel. To
all of these add drainage material - broken clay pots, stones or coarse
gravel, or polystyrene chunks in the bottom of the pot, and a mulch of
gravel on the top. What all of this means is that the plants never sit
in water, but have water constantly available unless the pot dries out.
If it does the soil part makes re-wetting far easier.
If
all you grow is annuals or tender perennials started afresh each year
you can completely renew the container soil each spring. Don't throw the
old soil out. It makes good mulch for the garden. For more permanent
plants renew the top 2 inches of the soil with fresh material as growth
starts in spring. Scrape off the gravel mulch and replace the soil with
fresh mixture.
Regular
feeding is a must. Use slow release fertilizer added to the
container soil when planting. This feeds the plants for a season but
there is nothing to stop you using any soluble organic fertilizer and
adding to the water once or twice a fortnight. Don't forget, the acid
loving plants will need their own type of fertilizer.
All
about watering. Never underestimate how much water most
container plants need. A large container - 18 inch diameter or above -
will need at least a gallon of water per session. In hot weather this
can be twice a day. A gravel mulch helps to conserve moisture, and
grouping the pots reduces evaporation, but container plants go through a
lot of water. If this is a problem, invest in an automatic watering
system which will keep the plants constantly moist. Alternatively, grow
plants that will stand some drought. A lovely pot of Aloe
aristata, a succulent, is will take days without water. Agaves,
pelargoniums, yuccas, sedum, sempervivum, cacti - if they can survive
your winters or you have a light frost-free place to overwinter them -
all are suitable.
Rule
4. Containers look better in a group. Unless your container
is exceptionally decorative a group of containers makes a far better
feature than a single pot. Pots can be added and replaced as required,
the group refreshed as plants go over, and new combinations tried when
you get tired of seeing the same arrangement. You can easily make
changes in a single container, replacing plants two, three or more times
a year. Try bulbs, wallflowers and pansies in spring, summer bedding
summer bulbs for the hotter months, autumn and winter interest from
chrysanthemums and foliage plants.
Rule
5. Grow permanent plants in their own container but combine single
season plants. This is one of the rules that can be
considerably bent but it is worth remembering that plants grow at
different rates and some could easily overwhelm their companions. This
is rarely a problem with summer bedding (although some modern strains of
Petunia have an astonishing growth rate) but combining perennial plants
in the same container can cause problems. Better to use one plant per
pot and group the pots.
Rule
6. Provide winter protection and guard against spring frosts.
In mild areas, most permanent container plants will survive the winter
outdoors. You still have to guard against the containers - and the plant
roots - freezing in the occasional bad spell, so pack the pots tightly
together under the house walls, use sacking to insulate the sides and
cover the plants with if frost threatens. In harder winter areas your
pots will need to be brought under cover and the plants hardened off as
spring turns into summer.
Rule
7. Don't plant permanent plants in overlarge containers. In
order to prevent the roots sitting in water, repot only when the
rootball reaches the sides and begins to mat. Then move the plants to
containers one or two sizes larger. For slow growing plants - pieris and
camellias for instance - it may take a couple of years before the plants
reach their final size. Once they do, root and top pruning every few
years will help to prevent deterioration. Think of it as bonsai on a
larger scale. For more information on this, see Potting and
Repotting plants.
Rule
8. Don't be frightened of using containers extensively. It's
your garden. A lovely small garden can be a tiny patch behind a town
house. You can grow hundreds of different plants in containers - lilies,
roses, peonies, clematis, camellias, annuals of all types,
rhododendrons, vegetables and fruits, and countless others. Large
containers and those on pedestals can be underplanted with flourishing
perennials and bulbs as well as colorful annuals or perennial
groundcovers. Even using simple plastic pots, you can arrange your
collection in such a way that foliage and flowers are the only things
visible for a magical effect.
