Diarmuid Gavin: Summer planning
Spring into action now for a colourful garden this summer
It may seem strange to begin to talk about the promise of summer colour when we are just over St Patrick's Day and about to welcome Easter, but successful gardening is all about planning well in advance. Even as our spring bulbs struggle with waterlogged soil and blankets of snow, we should look beyond this season to ensure we have some delicate sparkles of colour even after the herbaceous flowering period.
This requires planning and also some knowledge of the intricacies of flowering periods of different types of plants. So this week is about the potential of bulbs and tubers - not the ones flowering now, but the ones that will delight from summer to autumn. They are amongst the easiest of plants to grow with reliable and long flowering periods.
While some of the bulbs which flower in summer are hardy and are planted in the autumn (eg crocosmia, lilies and alliums), these can also go in the spring. However, many of our favourites such as dahlias (pictured) and begonias are tender and can only go out after frost. So now is the time to get them started indoors, either in your greenhouse or on a windowsill.
Begonias provide wonderful and colourful displays during the summer and are a staple of hanging baskets and bedding schemes. They're also extremely useful as they tolerate shade. Begonia tubers are available in the shops now or if you overwintered them, it's time to dust them off and get them going again. Place them sitting on moist compost, just lightly covering them. They usually have a concave hollow - this side should face upwards. Water them sparingly from below to prevent the tubers rotting from too much wet on their surface. Once green shoots emerge you can pot them up individually.
Here's an unusual one to try this year - the daffodil begonia. 'Daffadowndilly' looks like a daffodil but the flowers are a rich salmon pink. The unusual begonia blooms are held above dark green velvety foliage and will make for a unique display in your garden this summer.
The gladiolus murielae, or the Peacock Orchid, is such an elegant gladiolus: white with purple blotch at the base of the petals and sword-shaped leaves. These corms can be started off under glass in April. They prefer a loose-draining soil so adding sand to the compost will do this. Or you can plant them directly outdoors when the soil has warmed up a bit in late May and June so that you can enjoy their beautiful scent in late summer.
To keep your garden in full flower right through to the autumn, you shouldn't be without dahlias. They're easy to grow and in milder areas will still be displaying into October. As the tubers are tender they will be damaged by frost so you can't plant them directly in the ground until around late May. However, if you get them started off indoors now, your plants will get a head start and be flowering weeks ahead of outdoor planted ones. They're a great choice if you like cut flowers in the house, and the range of colours and shapes means there is a dahlia to suit everyone.
Any tender bulbs grown inside will need hardening off. This means getting them to acclimatise to outdoor life. Around late April or early May (after the last frost which varies according to what part of the country you live in) you will start popping them outside for a couple of hours each day. Do this for about 10 days and once fear of frost is past, they can take up their summer position outside. To maintain optimum flowering, feed every week with a high potash or tomato feed. If you don't have room or time to start these off now, you'll still be able to join in the fun by purchasing them as plug plants in the coming months.