Best of the bunch - Pieris

This beautiful shrub which thrives in acid soil looks fantastic at this time of year, when the new leaves on its dense, evergreen foliage turn bright red, then pink and creamy white, and it produces long sprays of blooms which look like lily-of-the-valley.

It needs little attention, other than to be planted in ericaceous compost, but prefers shade from the morning sun.

Among the most popular varieties are P. floribunda 'Forest Flame, while if you want something slightly different, there's a white and green-leaved variety called P. japonica 'Variegata'.

Pieris are ideal shrubs for an acidic woodland settings or in large pots of ericaceous compost.

Good enough to eat - Coriander

It's one of my favourite herbs, used to dress many Asian dishes or adding flavour to salsas, fiery dips and salads.

It needs to be sown in rows or patio containers every six weeks or so from late spring to mid-summer to ensure a long harvest, or on the kitchen windowsill for fresh leaves all year round.

If you're just growing leaf coriander, sow from late April onwards in a sunny, sheltered position in well-drained soil, in a place which will be partially shaded during the hottest part of the day to allow the leaves to retain their flavour.

Coriander doesn't transplant well, so sow it where you want it to grow. Seeds should be sown half a centimetre deep and then thinned slightly, although with leaf coriander you only have to do this if they're very overcrowded, and water them sparingly.

When the plants are 15cm high, cut the leaves, repeating this every month. If you want the seeds, you'll need to sow by May and thin the plants more, as to get a good crop of seeds the plant doesn't like to be crowded.

Good leaf varieties include 'Cilantro' and 'Leisure', which can be grown as a cut-and-come-again crop, keeping them around 10cm (4in) tall, while 'Moroccan' is good for seeds.

Three ways to... Beat weeds

1. As tiny seedlings appear, hoe every week or two, preferably on a dry, sunny day, leaving the weed seedlings to shrivel in the sun.

2. If you weed when the annual weeds are bigger, dig them out individually, clearing them away afterwards or they'll root back into the soil.

3. With tough, perennial weeds such as ground elder or bindweed, either use a systemic weedkiller, based on glyphosate, painted or sprayed on the offending plants on a dry day, which is absorbed through the leaves and slowly kills the roots. Wait a few weeks to see if regrowth appears and if it does, treat them again. If you are a committed organic gardener and don't want to use weedkiller, re-visit the offending weeds each week, removing all top growth, which will weaken and eventually kill them.

What to do this week

:: Put new aquatic plants in the pond, either in the soil at the bottom or using special aquatic baskets.

:: Earth up early potatoes.

:: Keep planting vegetables into the ground and under glass for a succession of crops.

:: Harden off aubergines which have been raised under glass, planting out under cloches and working a little general fertiliser into the bed beforehand.

:: Pinch out badly placed shoots on pruned rose bushes.

:: Plant crocosmia, galtonia, gladioli and nerine.

:: Net blackcurrants against birds.

:: Start pruning trained fruit tree forms, such as espaliers, fans and cordons, to encourage fruit bud formation

:: Plant evergreens and shift large specimens if necessary.

:: Remove cloches from strawberries during the day to allow access by pollinating insects.

:: Protect crops from carrot fly.

:: Prune Clematis montana after flowering.

:: Sow fast-maturing and late-flowering annuals directly into their flowering positions.