Containers for interest all year round
Where water is a scarce resource, container gardening can offer an opportunity to make the most of what is available – giving more to plants in active growth and less to drought-adapted plants such as succulents and bulbs.
Containers for plants can vary enormously, so bear in mind that you will want to move and change your display, bringing to the front those that are performing well at different times and ‘resting’ others.
Container gardens and plants in pots have become increasingly popular over the last few years. There’s now a category for container gardens at RHS Chelsea Flower Show and they are a good option for people with small gardens or balconies.
The gardening year here in the Algarve starts in autumn, with removal of summer colour annuals, trimming, and replanting plants. Propagation is a great way to have continuity for good plants and save the expense of buying new each season. Prepare pots for the winter months by dividing and splitting plants into smaller pots and feeding to promote new growth.
Winter in the Mediterranean is the main growing season so, when necessary, hand water as this helps ‘observing’ containers and any problems can be seen and dealt with early.
Spring is peak time for bulbs, especially tulips, small narcissi and muscari. Summer is show time for alliums, lilies, begonias, fuchsias and alstroemerias. In late summer, dahlias and salvias take over. Foliage plants such as cordyline, grasses and some herbs can provide colour, scent, movement and contrast. Native plants do not usually enjoy growing in containers and lavenders, cistus and phlomis will not thrive.
Use stone mulches or place smaller pots onto larger pots to avoid moisture loss – take care when using saucers under pots so that drainage is not impeded. It is possible to lift pots with bricks, which helps during any rainy weather. If compost becomes waterlogged, plants will rot. Drainage is vitally important in containers.
When starting a new pot, use a slow-release fertiliser which can be added to the compost and will last a whole season. Watering can leach nutrients from the soil in containers and poor water quality will have more impact for containers.
Bulbs are a great addition to any container and can be planted deep, especially in warm dry conditions. Crocks can be placed over the drainage holes in the base but just to keep the hole clear is enough. Use a nitrogen-rich compost and a potassium-rich feed, such as tomato food, to promote flowers.
Always water after planting except in the case of cacti and succulents. They need a couple of days to acclimatise and there is also the risk of rotting. It is possible to grow vegetables and salad leaves in containers, as feed and water can be better controlled than in the ground.
If you start planning your container garden, try to think about ‘right pot, right plant and right place’. Colour contrasts work well. For instance, deep red with silver foliage and fresh greens with white flowers. Dead head regularly and check for dryness by digging into the compost with a finger.
Dry soil on the top might not mean dry soil further down. A good ratio of plant to pot is about 1 to 1 ½ times foliage to pot. Do not overpot but move plants on gradually as they grow. Pots placed together closely provide shade from bright sun and promote a humid atmosphere. Try to build natural communities so that the pots might disappear altogether, and you get an impression of a garden flowerbed.
When planting, always put pre-soaked rootballs at the same level in a mixed pot and keep clear 2-5cm below the rim to allow for future watering.
Some safety hints together with more general advice:
- Plant the pot in situ to save heavy lifting
- If possible, bang down the pots to remove air pockets
- Keep the compost fluffed, not compacted, and add pearlite or grit for drainage
- Use larger plants within the pot to shade smaller plants
- Put in a layer of bulbs
- Wear sturdy shoes, not open sandals
- Always lift with a straight back
- Use more drainage for cacti and succulents
- Add broken pot shards to give crevice garden effect
- Use broken pots for small plants on surface of larger pots
- Put compost around all root balls, even those on the edge of pots
With grateful thanks to Harriet Rycroft. She enjoys helping people from many parts of the world to make the most of their container collection. Her new book ‘Pots’ is due out in October, and she has a colourful Instagram account.