Tips on how gardeners can revive their waterlogged lawns and bring them back to their former glory - plus, find out what else needs doing in the garden this week.

By Hannah Stephenson

If the recent deluge of rain means your luscious, closely-cropped carpet of green is now nothing but a soggy bog, you might be feeling a bit downhearted.

But don't despair, say the experts, there is still hope for your languishing lawn.

Guy Jenkins, Johnsons lawn seed expert, firstly advises to just give it time.

"Don't rush to work on your lawn as soon as the water has subsided," he says. "Treading on wet, saturated soil will easily result in compaction, reducing your lawn's aeration and drainage even further. Only sow seed after the ground has become workable again."

Sometimes though, the only real option is to start again; if your lawn suffers from consistent waterlogging, or is covered in moss or has bare, muddy patches. Jenkins says sorting out a proper drainage system and sowing trusted grass seed will save you time and money later. On a poorly drained site where water lies on the surface at times, land drains are the only solution. If in doubt, seek professional advice.

When water simply won't drain away, the RHS advises that you may have to replace the lawn with a new one, using turf laid on a 5cm (2in) bed of sharp sand, overlaid with topsoil improved by generous manuring and thorough cultivation.

Smaller lawns on heavy clay soil can frequently be drained by raising them slightly above the adjoining ground level. A gravel edging to the lawn will carry away excess moisture.

When a lawn lies wet for any length of time, damp conditions encourage algae, lichens and liverworts. This includes bubble-like Nostoc algae and dog lichen. They both flourish in badly-drained lawns but can develop wherever the aeration is poor and may even appear on well-drained turf if the surface has become compacted and is inclined to remain damp after rain.

Algae also thrives in shaded conditions and where soil fertility is poor, so it's frequently found on turf beneath trees. Moss is a common sight where conditions are damp, but particularly if there is shade and an acid soil.

Pricking or slitting the surface can improve a waterlogged lawn, the RHS adds. Try making 2-3cm (1in) slits or holes, although deeper spiking is better, especially with a tool designed to leave holes 10-15cm (4-6in) deep. These holes can be filled with a free-draining material, such as proprietary lawn top dressings or horticultural sand, which will allow the water to flow from the surface to deeper, less compacted layers.

Hand spiking tools are available but an ordinary garden fork can be used too. Alternatively, for larger lawns, use powered tools. Try a hollow tiner, which has hollow spikes and removes plugs of soil that are then swept up and removed. Pricking and slitting are best carried out once the excess water has drained away, especially where machinery is to be used. In small areas where standing water persists, sweep it off the lawn and into the beds before spiking with a hand spiking tool or garden fork.

Once you've cleared the latest mess, it is also important to consider the root of the problem and hopefexampleully prevent it happening again. For exmaple, do you live in an urban area, at the bottom of a valley or flood plain, or on top of heavy clay?

"All of these factors can affect how your lawn copes with excess rainfall," says Jenkins. "In urban areas, water flows over pavements and patios, with the extra surface run-off resulting in flooding.

"Simply by keeping a well-maintained lawn, providing somewhere for water to drain away, we can all do our bit to prevent flood damage."

If you plan to sow a new lawn this spring, raking soil over to form a fairly fine tilth should ensure optimum germination rates, but only do it when the soil is dry enough to work.

Heavy rain washes nutrients out of the soil, so to help encourage new grass, apply a lawn fertiliser or buy grass seed which includes fertiliser or dressing, so that it can grow more extensive root systems better able to withstand drought and flooding.

Best of the bunch - Forsythia

The forsythia is always a welcome sight in spring, its bright yellow tubular flowers appearing on long stemmed branches before the leaves. These deciduous shrubs, which make good hedging or sit easily among other plants in shrub borders, will grow in moist but well-drained soil in sun or partial shade and should be pruned after flowering as they usually flower on the previous year's growth. Pruning immediately after flowering allows the maximum time for development of young growth to provide the following year's flowers before the end of summer. Early blooming shrubs like flowering quince make good companions as they offset the forsythia's bright yellow blooms. Other plants that co-exist well with forsythia are vines such as purple wisteria, which blooms after the forsythia, providing more colour for a longer period. Good varieties of forsythia include 'Lynwood Gold', 'New Hampshire Gold', 'Kusma' and 'Golden Bell'.

Good enough to eat - Sowing peas

Many people may only know the frozen kind, but there's nothing quite like shelling fresh peas into a bowl in summer, and eating a few as you go along.

At this time of year you need to sow peas under cover in modules. If you have a small garden but want to make the best use of vertical space, choose a tall variety such as 'Alderman' and give it good support.

However, there are many much shorter cultivars, including dwarf varieties, which are virtually self supporting and suitable for containers.

Pea seedlings can be transplanted into the ground when they are around 10cm (4in) tall, and if the weather is cold protect them with fleece. Insert supports around the plants.

They like rich, moisture-retentive soil which has been enriched with compost or well-rotted manure to help see them through hot weather, which they dislike. You'll need to water them well and mulch around the base of the plants.

Sowing seed in a single row or pair of rows works best for taller varieties as it makes it easier to support them and give good ventilation around the plants.

Keep them well-supported and water well once flowering has begun to allow the pods to swell properly. Harvest them regularly to ensure they are at their peak.

What to do this week

:: If the ground isn't too wet, plant herbaceous perennials including geranium, astrantia and oriental poppies.

:: Plant out onion sets to their required spacing, usually about 10-15cm (4-6in) apart along the row.

:: Hard-prune stems of dogwoods and willows to encourage a flush of new shoots.

:: Lift and divide marginal plants which have grown too large.

:: Cut back ornamental grasses and other perennials left for winter interest, if you haven't already done so.

:: Improve drainage by hollow spiking the lawn to help prevent the problem recurring.

:: Keep grass trimmed away from the base of trees growing in grass, as this can compete for moisture and nutrients.

:: Finish winter-pruning gooseberries, shortening long site shoots and removing congested stems to create open-centred bushes.

:: Protect the blooms on cherries, currants and early-flowering fruit from frost.

:: Cover soil in the kitchen garden with polythene or cloches to warm it up for early sowings.

:: Open the lids on cold frames each morning to improve ventilation, closing them again each evening.