When container spring bulbs are over and stored away or planted out in the garden, the vacant pots they left are a chance for a heart-gladdening display of colourful summer bulbs and tubers.
Some, such as begonias and dahlias flower repeatedly once they start while others such as acidanthera and Pineapple Lily keep blooming for many weeks.
Agapanthus is not outstandingly long-flowered at first, but its usually blue blooms are spectacular and their tall seedheads are pretty in winter vases.
When it’s kept happy with rich feeding, water and bonemeal, its tubers increase into large masses which in time produce masses of blooms. Agapanthus is well-suited to containers because it well-tolerates being potbound. But all the evergreen kinds are tender, and should be taken inside for winter.
There are hardier deciduous amaryllis but the variety I grew was much smaller than evergreen amaryllis but hardy overwinter in zone 7. My experience was with Cally Hardy mix (seed from www.chilternseeds.co.uk).
Containers are very suitable for slug-prone plants because it’s easy to wrap some copper slug tape around the pot, and they’re safe for a couple of seasons. That’s why aside from their huge range of colours and shapes, the smaller type containerized dahlias are carefree as well as gladsome once they start blooming.
But big dahlias like the dinner-plate varieties do tend to drape their leaves down the sides unless you imprison them with tomato cages.
Like agapanthus, dahlias enjoy a sunny spot and love soil amended with compost or low-nitrogen fertilizer. They need a lot of water, too, especially since containers tend to dry out quickly. Given this, the tubers enlarge into very impressive clumps quite fast.
The colours and shapes of dahlias are incredibly varied from solid reds, yellows, whites and pinks to very busy mixes and matches like yellow-tipped reds or apricot and pink blushes and ones that shout across a garden such as the blood-red wine and white of the dinner-plate dahlia ‘Tartan’.
People challenged by containers in shady places will find begonias the ideal plant for their situation. Begonias need shade. You’ll be advised to start your begonia several weeks before frost. That’s good advice – when you’re dealing with a begonia that’s already a long-time friend.
But when you’re going to acquire a new begonia, it’s useful to choose one already in flower so that you avoid colour surprises. That’s because when treated well, begonias are a very long-lived plant which can be stored year after year, encouraged to sprout early and after frost put back in its summer home.
Begonias always spring late into flower, but after that they don’t stop until frost.
Callas are more popular each year now that they’re appearing in a variety of colours. Also people have discovered this plant’s love for shade. They also love moisture and protection in winter. The coloured callas are especially tender.
There is a larger, sturdier white-flowered calla which can be hardy on the Coast in a warm, sheltered place.
One easy and inexpensive summer bulb is acidanthera. It looks like a white narcissus with a splashy wine-red throat, is hugely fragrant and flowers for ages. During winter corms can be stored in mesh bags like narcissus.
