In your ornamental garden in March

General tasks

• Sow some hardy annuals such as Alyssum, Calendula, Eschscholzia, Limnanthes doulasii and Nigella - there are many more varieties to choose from in the Organic Gardening Catalogue.
• As the temperature increase so will weed growth. Keep a check on young weeds and remove them before they take hold.
• Spread mulches of compost or well rotted manure over herbaceous borders.
• Make a wigwam frame, place in a suitable place in a flower border and direct sow two sweet pea seeds at the base of each cane.
• 
  Viburnum tinus

• Prune summer-flowering shrubs like Buddleja davidii, Spiraea japonica, and hardy Fuchsia. They benefit from cutting down hard in early spring. If your garden is prone to late frosts, then cover the cut stems to protect new shoots.

  DON'T PRUNE spring flowering shrubs and climbers until flowering has ended. Wait until flowering is over, then prune as required - cutting back hard or re-shaping if necessary. If you want to reduce an overgrown tangle now, just remove a few selected branches to thin things out somewhat.

  Typical examples include Forsythia, Clematis montana, Spiraea x arguta and Buddleja globosa, Viburnum tinus and Ceanothus burkwoodii

• Finish tidying up last years dead growth on perennials before they start into growth as weather warms up.
• Regularly clean bird tables and birdbaths, provide fresh water and food. Birds are much more active this month, mating and nest building.
• Provide nesting materials such as pet hair, small twigs, straw and other suitable materials. Tie them in loose bundles and attach in trees or other places where birds perch around the garden.

Greenhouse

• Top-dress any large potted plants. Scrape off as much of the old compost as possible but be careful not to damage surface roots. Rich garden compost is ideal as a top dressing and a final thin mulch of horticultural grit will help retain moisture in the warmer months.
• Pot on any half hardy and tender perennials. A mix of good garden compost and 20% grit is often ideal for this. If you grow Agave and various cacti then increase this to 40% grit. Always wear thick gloves when potting on spiky plants. Cacti with small fine spines can be the worst offenders leaving dozens of spines in your hands that can take days to remove.
• Pest populations may start to increase dramatically. Be vigilant and deal with any pests promptly. This will help prevent any serious infestations building up as plants come into fresh growth. Scale insects are a particular problem on citrus trees. Start to deal with them now. Click to view our factsheet on Scale Insects
• Divide half-hardy and tender perennials, like Hedychium, Musa, Aspidistra, Agave and Aloe. Keep them well watered for a few weeks until you see active new growth.
• Sow seeds of perennials in modules. Plants establish quickly and are easy to pot on as root damage from pricking out is minimised.
• Fuchsias in pots that have been dormant will need watering now and dead stems cut back.

Lawn care

• 
  Give lawns a boost
• The grass will be growing steadily now. Make sure your mower is serviced and ready to go for the first cut of the season.
• Before mowing, remove thatch and moss by scarifying with a lawn rake. Set the mower blades to a higher setting (3cm) for the first few cuts.
• Stay off or try to minimise activity on your lawn if it is wet, it will turn to mud very quickly in the wet.
• If you have areas that get compacted, spike deeply with a garden fork. Get the fork to penetrate to the total depth of the tines and wiggle the fork about a bit to make the holes bigger. Repeat this all over the wet area and a little around it. This will help water drain away much more quickly.
• Give your lawn a feed. Try the Chase lawn fertiliser (spring treatment) from The Organic Gardening Catalogue. It has N; 9%, P; 3%, K: 3% and is ideal organic spring feed for your lawn.
• Re-seed any bare areas. Scratch the surface with a lawn rake and then sow. Net larger areas to prevent the birds from eating the fresh seed.

Ponds

• 
  Frogs emerge from hibernation
• Remove fallen leaves and other decaying plant debris from ponds. Frogs and other aquatic life will be emerging from winter hibernation so a good tidy up now prevents stagnation and build up of algae.
• Check submersible pumps, they can be cleaned and put back in the pond.
• Choose new plants for the pond, a good assortment will provide food and shelter for many pond loving creatures.
• Include those that float, oxygenate the water and those that prefer shallow water planting.
• Aim to keep at least half the surface covered with plants to reduce algal growth.
• Avoid plants that become very invasive, these include water fern, Azolla filiculoides, parrot's feather Myriophyllum aquaticum and curly waterweed Lagarosiphon major. These exotic plants can escape from garden ponds into the wild, choking our rivers, ponds and waterways and potentially damage our native wildlife.
• Visit the Wildlife Trust website www.wildlifetrusts.org for further details about invasive pond plants.
  

What to plant in March

As well as the suggestions below, March is a good month for planning and carrying out new planting of trees, shrubs, perennials and annuals.

• 
  Lonicera Fragrantissima
  a beautiful scented winter flowing shrub
  and widely available

• Plant summer flowering bulbs such as gladioli and lilies towards the end of the month, depending on your soil conditions. They don't like sitting in waterlogged soils. If you have heavy clay, line the planting holes with a layer of coarse grit.
  
  Alternatively plant bulbs in pots for adding colour in gaps around the borders later in the season.

• Cyclamen in their various forms are easy to find at the garden centre but make sure you buy the hardy varieties.

• There are a few shrubs that are easy to find and will add a lot of colour to the garden in early spring. Try Magnolia 'Galaxy', Magnolia 'Jane', Corylus avellana 'Contorta', (contorted hazel) and Hamamelis x intermedia 'Jelena'.

Make new plants

Now is the time to dig up and divide all those hardy herbaceous perennials. It is still too early to divide grasses and bamboos though, leave them until May.

• Divide overgrown clumps of herbaceous perennials. Cut the tops back to 25mm-50mm and lift the whole plant out with a fork. Look for a natural line across the plant and cut it with a sharp knife right through, continue dividing like this until you have enough plants to suit your needs. Replant the pieces in groups of three to five to make an impact in ornamental borders from repeating colour schemes or pot up spares immediately, water well.
• Divide snowdrops towards the end of the month. They prefer to be planted 'in the green' once they have finished flowering. Alternatively purchase snowdrops from a reputable supplier then you can be sure that they haven't been taken from the wild.
• Sow seeds, either direct for hardy annuals or into modules for hardy perennials. This is the very best way to sow your perennials, as root damage from pricking out is non-existent. Plants establish quickly and are easy to pot on.

Easy perennials

This section gives you our suggestions of perennial plants that will look good or are looking good now, are easy to grow and fairly free of pest and disease, making them a good bet for an organic garden. All plants marked with a * indicates an Award of Garden Merit (AGM) from the RHS.

• Anemone blanda* is a beautiful bright blue, low growing perennial and feathery green leaves. A. blanda flowers from March right through to April and is easy in sun or part shade. Look out for the varieties A. blanda 'Radar'* with lovely bright pink flowers and a white eye and A. blanda var rosea which has a more subtle pink flower and white eye. A. blanda 'White Splendour'* is a stunning pure white variety and ideal for brightening up a shady corner.

• Primula are well known plants and important for attracting and feeding early flying bees and insects. Some of the very best Primula are the native ones. The primrose, Primula vulgaris is a beautiful and easy plant to grow, it likes grassy banks and woodland edges and it is easy to find a spot in any garden that will suit it. Grow it in full shade or full sun, it seemed very happy in both.
  
  There is a really lovely pink sub-species called Primula vulgaris ssp. sibthorpii*. Primula veris* or cowslip is another good native Primula are happy in the border, with its pretty yellow flowers held high on a stem it is well worth having. Primula elatior* or oxlip is in a way the best of both worlds of native Primula, as it has the tall stem of P. veris and the large pale yellow flowers of P. vulgaris. P. elatior has many sub-species to look out for, even a pink one called P. elatior ssp. meyeri but unfortunately this is very difficult to find.

• Pulmonaria are also diverse and easy to find. They tend to be low growing and come in a variety of colours from whites, pinks, blues and even red. Pulmonaria are happy to grow in full to part shade, they flower early in the year and keep their attractive foliage until the first frosts the following autumn. P. angustifolia* has deep blue flowers and large narrow oval leaves it is particularly useful in dry shade under trees or hedges. P. longifolia 'Margery Fish' * is one of the very best Pulmonaria with very light green leaves (as though all the speckles have joined up) and pinkish blue flowers, if you can imagine such a thing.
  
  P saccharata is probably the best known of the Pulmonaria and widely available. P saccharata has many cultivars, P. saccharata 'Mrs Moon' has broad leaves and pink flowers that fade to blue, P saccharata 'Sissinhurst White'* has small pale green leaves, with small speckles and pure white flowers, you need to find good stock of this variety as some seem a little sickly. P. rubra is a lovely red or bright pink species that is easy and also happy in the sun as well as shade. The very best of all is P. officinalis 'Opal' a stunning pale blue variety with lightly speckled leaves, 'Opal' holds its flowers up above the leaves and really shows off.

• Pulsatilla vulgaris* is a British native and particularly useful as it does not mind dry, sunny positions. In its natural state it lives on grassland and is often found on chalky soils. Pulsatilla vulgaris has delicate feathery leaves and striking purple flowers with a rich yellow centre. Both leaves and flowers emerge at the same time. P. vulgaris 'Alba'* is a good clean white form and both the species and the white cultivar are easy to grow and find at the garden centre. There are many other Pulsatilla worth trying if you see them. P. alpina is another good white and P. alpine ssp. apiifolia* is a beautiful primrose yellow with a deeper centre and again both will tolerate a dry and sunny position.

Pest & disease watch

• 
  Ladybird larva feeding on aphids

• Look for first signs of aphid infestation on newly emerging shoots. Aphid colonies can rapidly take hold especially during warmer spells.

  Members: See our factsheet on Aphids for ways to keep this pest under control.
  (Factsheet requires members' password)

• Watch for 'damping off' disease in seedlings in the greenhouse or indoors. This fungus causes the stems to collapse and the seedlings to fall over.
  • Ensure that seedlings get enough light to prevent them becoming 'leggy' and turn seed trays daily to ensure even growth.
  • Overcrowding and damp also contribute to 'damping off', so don't sow seeds too thickly and keep watering to a minimum. It is better to have a tray of fewer, healthy plants than to lose many to this disease.

• Lily beetle

  Check Lilies, Soloman's seal and Fritillaries for first signs of this conspicuous, bright orange/red beetle towards the end of March. Adult beetles overwinter in the soil, moving up into plants from late March onwards. Remove and destroy any adults and keep checking plants through April, wiping off any eggs and slime covered larvae that you find on the leaves.

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