Gardener's diary - March gardening

Try to finish all planting by the end of the month in milder climates; in colder climates it can be left another 2-3 weeks.

Sowing of perennial seeds can be done for plants such as Delphinium, Aquilegia and Gypsophila. If sown in gentle heat plants will germinate within 3 weeks.

Michaelmas daisies and Delphiniums that have over-wintered in the greenhouse should now be suitable for taking cuttings.

As long as the soil is not too wet add a dressing of bone-meal to beds prepared for the sowing of annuals and break up the surface to produce a tilth.

Cultivate the soil around biennial plants if you have not already done so.

Sow seeds for Ageratum, Dahlia and Zinnia, amongst others. Seedlings that have been pricked out can be moved to a closed cold frame towards the end of the month. Seeds sown in February can now be pricked out.

March is the time to prune those shrubs which, like Buddleia, will flower later in the year on the new growth. Plants which flower on the previous year's growth, for example Forsythia, should be pruned immediately after flowering.

As soon as the weather allows trees bought from garden centres and nurseries should be planted in moist soil and well watered in.

Complete planting of deciduous bare-rooted hedges and container grown specimens. Prune established hedges and spray with fungicide.

Prune rose hedges by removing dead and weak growth and cutting other stems back by a third.

Trim annually, the timing depending on the type of heather. Trim winter heathers immediately after flowering. For summer flowering heathers remove flowered growths. Take care not to cut back into old wood of both types.

If you didn't take cuttings in the summer then heathers can be propagated by layering. Complete any planting not finished in the autumn.

Snowdrops can be moved now. They are an exception to the rule about moving plants whilst still growing.

Plant Gladiolus as soon as the soil permits.

In Alpine houses increase the amount of watering and ventilation. Continue potting up seedlings and divide and re-pot those plants that need it.

Rock gardens and raised beds should be cleaned up and specimens planted now will have a greater chance of surviving a dry summer. Lay slug pellets as these plants can be particularly vulnerable.

This is the beginning of the mowing season. Check for worm casts before mowing and roll the lawn if needed before cutting with the blades set high. Collect clippings to prevent clogging and apply a lawn fertilizer.