Choosing annuals for tubs
Q Apart from lobelia, which blueflowered annuals work well in tubs? SHARON CARTER, DURHAM
A Lobelia is the best known blue annual, although there are pink, red and white forms too. A useful trailing alternative for baskets is isotoma with pale pink starry flowers, which are also fragrant. Didiscus is a similar, powder blue, though taller and good for cutting. Don’t forget nigella, ageratum, pansies and petunias.
Q Is it too late to sow my basket plants? MARY PHILLIPS, KIRKLEES
A Bedding plants can be sown at different times, depending on how quickly they flower from seed. People often sow begonias first, because the tiny plants grow slowly. It’s too late to sow them now (May). Marigolds and other fast-growers can still be sown now and will flower this summer. Although they’ll bloom later than most, they should still be looking good at the end of summer. Others to try include cosmos, dahlias, zinnias and hardy annuals such as nigella and poppies.
Q Which are the best plants for pots that only get a little sun? JAN PAINE, DARTFORD
A Begonias of all kinds are the best choice and will give a colourful display for the longest season. Fuchsias are another option and often do better in a little shade than in full sun. Lobelia will also grow and flower well, as will mimulus and most summer foliage plants such as coleus and lamiums.
Q How can I tame my overgrown potted carex? HEATHER WILLIAMS, NEWCASTLE
A Now is the ideal time to remove your Carex oshimensis from its pot and divide it. The roots will be dense and will need to be cut, vertically, into sections with a knife, then repotted. Take the opportunity to remove old leaves and trim the rest back by about half to reduce water loss. Tidy it while it’s re-establishing.
Q Can I keep winter pansies? EMMA SCOTT, BLACKBURN
A Winter-flowering pansies usually peak in April and May, but as the weather gets hotter and they set lots of seed they start to get exhausted and fade. If they’re in a cool spot, trim them over and feed them well and they should sprout and flower again. There is a risk that they’ll give up in midsummer, so it would be best to replace them in July.
Q Why have my bedding dahlias turned yellow? FRANCES PRICE, EXETER
A It’s important to gradually harden off young plants to outside conditions after being grown in a greenhouse. Without acclimatising them, young plants can be scorched by bright sunlight, bleached by cold winds or damaged by frost. Plants should recover but the existing leaves may well die.