RHS diary: March - Telegraph Barley straw can be useful in reducing the growth of algae in ponds, but it needs to be put in place now to be effective. Most gardeners either overlook feeding bulbs or feed too late, when they are in bloom. Sow fresh seed of parsnips in clusters of five seeds 6in apart, to ensure there are no gaps in the rows of this slow-to-germinate vegetable. Hard-prune dogwoods and willows grown for their bark colour to get bright, young stems for next winter. Guide to useful kit Garden sieves come in all shapes and sizes, but one of the most useful when sowing seeds is the Burgon & Ball potting riddle. The circular plywood frame supports a 4mm galvanised mesh, ideal for covering small seed with a light covering of sieved compost. Measuring 8in in diameter, it's also compact and light enough for single-handed use. The traditional design goes hand in hand with robust construction, which should see the product outlast most of its owners. burgonandball.com RHS news and events It's the start of the Grow Your Own calendar in all of the RHS gardens this month, with events and activities to encourage everyone to have a go at growing fruit and vegetables during the Grow Your Own Weekend (March 24-25). From planting demonstrations and expert advice to cookery demonstrations and seed planting for children, there's something for every level of gardener. To find out what's on, visit rhs.org.uk/gardens. Marvel at the orchids in the glasshouse at RHS Garden Wisley (March 17-April 15) where popular and rare varieties combine to make an amazing display both at ground level and up in the branches. See rhs.org.uk/wisley. Visit the RHS London Orchid & Botanical Art Show (March 16-17), where you can browse and buy from a spectacular array of orchids by specialist growers from across the globe, and enjoy work by top botanical artists. At RHS Garden Hyde Hall, treat your mother to a special lunch over the Mother's Day weekend (March 17-18). Enjoy the spring colour emerging in the garden before a special meal with local, seasonal produce in The Barn Restaurant. Two courses for £21.95, three for £23.95. Booking essential (01245 402103; rhs.org.uk/hydehall). If you've ever wanted to try beekeeping, buzz along to RHS Garden Rosemoor on March 21. First Steps in Beekeeping will cover where to locate a beehive, bee behaviour, what equipment you need and much more. Honey and beeswax products for sale. For details, visit rhs.org.uk/rosemoor. Time to plant evergreen shrubs Spring is the ideal time to plant evergreen shrubs, such as camellias, daphne and skimmia, as they establish well in a warming soil. Unfortunately, a good deal of "advice" on how to plant trees and shrubs is nonsense; poor planting technique is only exceeded by a lack of aftercare as the most common reason for failure. It pays to take a little time to select good, healthy plants with well-balanced branches. Check that the plant is not root-bound and avoid pots covered with moss or weeds. Ensure the species is suited to the conditions in your garden. Most shrub root activity takes place in the top 12in of the soil, so dig a hole about a spade depth deep but three times the diameter of the container. On a good soil it is not necessary to add any organic matter but on poor sandy soils consider mixing about 10 per cent organic matter with the soil set aside for backfilling. Ignore advice not to "disturb the root ball." Thoroughly tease out the roots to ensure they grow into the surrounding soil. Do not plant too deeply. Scrape off the excess compost from above the root collar - the point from which the main roots flare out from the trunk. Use a cane to check that the root collar is level with the surrounding soil. Replace the backfill, using your heel to firm the soil. Water well. Mulch over the root area with compost, mulching bark or manure to control weeds and conserve moisture. But keep the mulch away from the trunk. During the first two years, water well once a week with up to a bucket of water in dry spells to ensure the water reaches the bottom of the roots. For more information, see rhs.org.uk/advicesearch. Plant of the month Daphne odora 'Aureomarginata" AGM Flowering from midwinter to early spring, this is one of the less demanding daphnes but impressive nonetheless. The rounded, evergreen shrub grows to about 5ft and bears lance-shaped, glossy, deep green leaves, narrowly edged with yellow. The clusters of very fragrant red-purple flowers are almost white within. Hardier than the normal form, 'Aureomarginata" was once known erroneously as Daphne japonica. Although introduced from Japan, where it has long been cultivated, it is native to China.