Home Jobs March gardening jobs

March gardening jobs

Here are your gardening jobs for the month – with added links if I have more information on the subject. They are all still relevant to do now if you’ve fallen behind or if the weather’s been bad.

Packed-out propagator
Packed-out propagator – not this year, I’ve barely started

Week 1

This is the start of the main sowing period (March-May) for a huge variety of hardy annuals, half-hardy annuals and vegetables. Judge by the weather, the current conditions and what protection you can provide whether it’s time for you to sow or not. Seeds will rot in freezing or waterlogged conditions outside – try starting crops off in modules in a cold greenhouse, cold frame or propagator, then harden off to be planted out. IF IN DOUBT, PUT IT OFF!

Sow seeds in modules/pots in an unheated greenhouse: broad beans, leeks, lettuce, rocket, coriander, peas and Swiss chard. Sow sweet peppers, chillies, tomatoes, cucumbers, aubergines, celery and globe artichokes in a propagator.

Sprinkle granular fertiliser around clumps of spring bulbs.

This is the best month for planting roses in heavy soils or in cold areas. Don’t plant a rose where one was grown before, otherwise, new introductions may suffer from replant disease. Feed plants with a granular rose fertiliser as they come into growth. Prune established bush and standard roses as they start growing but before any leaves unfurl.

Onion Rumba sets
Onion Rumba sets, March 2013

Plant onion sets in modular trays of compost, raising plants under cover to plant out later.

Dig compost into borders (if workable) to improve water retention and clean up fallen branches and leaves as you go.

Hoe bare areas of soil on dry days to remove weed seedlings.

Keep feeding the birds and put up nesting boxes.

Photinia Pink Crispy, Magnolia Sunsation and Acer shirasawanum Jordan, February 7
Photinia Pink Crispy, Magnolia Sunsation and Acer shirasawanum Jordan, February 7

Buy and plant shrubs and perennials as soon as possible. It gives them more time to get their roots established before the growing season – drought and heat kill more first-year plants than the cold.

Cut back ornamental grasses and other herbaceous perennials to make way for the new growth. Lift and divide large clumps of hosta, or any other hardy perennial with a crown.

Plants infested with couch grass and other perennial weeds should be lifted so the roots of the weeds can be removed. Improve the soil by digging in organic matter before replanting.

Add copper rings to pots to protect plants from slugs and snails.

Hello Hellebores, January 31
Hello Hellebores, January 31

Cut off old leaves of hellebores that produce flowers from ground level to expose the flowers and remove hellebore leaf spot.

Continue to deadhead winter-flowering pansies. Watch out for downy mildew and black spot. Remove any infected leaves and destroy badly affected plants.

Aphids can multiply rapidly during mild spells. Protect sweet pea plants in particular, as they can get sweet pea viruses, which are transmitted by the sap suckers.

Plant deciduous hedging plants, shrubs, trees and climbers.

Last chance this month to prune late-summer flowering deciduous shrubs, such as Buddleja davidii, Caryopteris clandonensis, Ceratostigma, Hydrangea paniculata, Leycesteria, Lavatera, Perovskia, hardy fuchsia, and deciduous Ceanothus. Shrubs such as Eucalyptus gunnii and Cornus sanguinea cultivars are cut back very hard to deepen the stem colour and keep them manageable.

Prepare seedbeds, covering them with polythene or fleece to warm up the soil before sowing. Try to avoid digging in wet weather – work from a plank of wood, to avoid compacting the soil. Try not to fall off.

Clematis Mme Julia Correvon still blooming at the end of October
Clematis Mme Julia Correvon still blooming at the end of October

Cut back late summer and autumn flowering (group 3) Clematis, if not done last month. Cut to the lowest pair of strong buds above ground level, then mulch and feed.

Prune back stems on pot-grown overwintered fuchsias, and place them in a well-lit, warm spot to re-shoot. Pot them on in fresh compost and start feeding six to eight weeks later.

If you have seedlings and cuttings in the greenhouse, make sure they are getting the maximum light, or they will become weak and leggy. Turn them once a day so that they get light on both sides.

It’s your last chance this month to plant bare-root fruit trees, and ideally plant container-grown ones too. Apply a mulch around fruit trees, nuts, and bushes as long as the ground isn’t frozen and repot or top dress container-grown fruit.

Continue chitting early and maincrop potatoes.

Pot up or plant out strawberry runners
Pot up strawberry runners

Week 2

Plant strawberry runners in hanging baskets to grow in the greenhouse for an early summer crop.

Divide clumps of herbaceous perennials that you want to propagate, those that have become too large for their allotted space, and those that are flowering poorly or have lost their shape. Divide hostas before they come into leaf.

Repot established Agapanthus into slightly larger containers. Plant begonia and Gloxinia tubers in pots.

Prune out old stems of elder (Sambucus) to promote new growth from the base.

Prepare soil for summer-flowering bulbs like gladioli
Prepare soil for summer-flowering bulbs like gladioli

Plant summer-flowering bulbs, such as Gladioli, Tigridia, Galtonia, Eucomis, Anemone, lily and Acidanthera. Prepare the soil first, to make sure that drainage is enough to prevent the bulbs from rotting. If in any doubt, wait.

Propagate dahlias from tubers. Pot them up in multi-purpose compost so that the old stalk is just above the surface. Water and place in a warm, light place or in a propagator. Once the fresh shoots have grown to 7.5-10cm (3-4in), cut them off with a knife. Dust the ends with hormone rooting power and push them into a pot containing cuttings compost. Place back in a propagator or plastic bag until roots appear.

Mulching with a deep layer of organic matter helps to condition the soil, suppress weed growth, insulate plant roots from temperature fluctuations, and conserves soil moisture during summer.

Peach dahlia
Peach dahlia, Harrogate Autumn Flower Show

Feed borders with a general-purpose fertiliser, such as Growmore.

Roses will benefit from feeding with a granular rose fertiliser as they come into growth. Finish pruning established bush and standard roses as they start growing but before any leaves unfurl.

Mulch raspberries, blueberries, cranberries and lingonberries with well-rotted farmyard manure (not mushroom compost as it is too alkaline).

Untie canes of blackberries and hybrid berries that have been bundled together for winter, and train into arches before the buds burst.

Glorious red kale
Glorious red kale

Feed crops that have stood all winter, such as kale or chard.

Start preparing runner bean supports and trenches for sowing (in May) or planting out (in June).

Sow seeds in modules/pots in an unheated greenhouse: broad beans, leeks, lettuce, rocket, coriander, peas and Swiss chard. Sow sweet peppers, chillies, tomatoes, cucumbers, aubergines, celery and globe artichokes in a propagator.

Yellow Bouquet lily
Bouquet lily. Picture; Sue Welford

Week 3

Sow dwarf French beans under glass in a large pot for an early crop in June.

Plant lily bulbs in pots to transplant into the border.

Take cuttings from Dahlias planted last month to raise new plants.

Sow hardy annual flowers where they are to bloom if your soil is workable, such as Calendula, Nasturtium and Nigella. You can also sow them in modules if you have space in an unheated greenhouse to give them a faster start.

Snowdrop time
Snowdrop time

Divide and/or plant bulbs-in-the-green, such as snowdrops (Galanthus) and winter aconites (Eranthis hyemalis), if not done last month.

Check whether containers need watering. Sheltered pots can miss out on any rainfall. Pots and tubs benefit from topping up with fresh compost.

Check autumn-sown sweet peas and apply mouse and slug controls if necessary.

Sweet pea Harrogate Gem
Sweet pea Harrogate Gem

Feed trees, shrubs and hedges with a balanced fertiliser (such as Growmore or blood, fish and bone), sprinkling it over the root area before hoeing into the soil surface.

Delay pruning spring-flowering shrubs until after they have flowered. Don’t prune slightly tender evergreen shrubs (such as Choisya, until April), but do tackle hardy types. Remove reverted green shoots on variegated evergreens.

Overgrown climbers can be renovated. Deciduous varieties will be at bud burst now, so you can tell which growth is dead and alive – suitable for Lonicera (honeysuckle), Hedera (ivy) and rambling roses.

Cacti should be kept dormant until spring is definitely underway, then increase watering and feed to bring it into active growth.

On mild days, open vents and doors of greenhouses to reduce humidity and help prevent disease.

A beautiful sight in blossom - plum Lizzie
A beautiful sight in blossom – Japanese blood plum Lizzie on March 25

Apply a nitrogen feed to plums, cherries, cooking apples, pears and blackcurrants.

Prune blueberries and apply sulphur chips to beds of blueberries, lingonberries and cranberries if needed.

Sow under cloches: carrots, beetroot, broad beans, salad onions, cauliflower, cabbage, Brussels sprouts, spinach, leeks, lettuce, rocket, coriander, mixed salad or stir fry leaves, radish, turnip, peas and Swiss chard.

Daffodil Minnow

Week 4

Plant first-early potatoes in sacks, as long as you can protect the haulm from frost.

Cut the spent heads off narcissus and daffodils, but leave the leaves to die back naturally.

Sow wildlife-friendly flower seeds where they are to flower, such as honesty or verbena to encourage insects.

Sow summer bedding plants in a heated propagator or under glass.

Primula Moonstone divisions, January 8
Primula Moonstone divisions

Divide hellebores and polyanthus-type Primula after flowering.

Top dress spring-flowering alpines with grit or gravel to show off the plants and to help prevent stem rots.

Improve the drainage of heavy soils by working in lots of organic matter.

Get herbaceous perennial supports in early, so that the plants grow up through them – I use sturdy twiggy branches. Adding rigid supports later looks unattractive. Crisscrossing strings from hidden or posts works well, allowing stems to grow up in the gaps between strings.

Hosta before bud break
Hosta before bud break

Continue to protect new growth on lilies, delphiniums and hostas, etc, from slugs and snails.

Prunus species (ornamental cherries, plums and almonds) are vulnerable to silver leaf if pruned before midsummer, and should not need routine pruning if planted with enough space for their eventual size.

Remove netting placed over the pond to protect it from leaf fall. Divide marginal and bog garden plants if overcrowded. Contain vigorous perennials by planting in aquatic plant baskets and top with a layer of gravel. Cut back old marginal vegetation.

George eating ribbon grass as fast as it grows in the pond

Protect fruit blossom from frost, but make sure insects can reach the flowers or else hand pollinate them.

Switch to a summer feed for all citrus trees and increase watering.

Pollinate strawberry flowers under glass by brushing over them with your hands. Plant out cold-stored strawberry runners.

Plant onions, shallots, garlic, Jerusalem artichoke tubers and asparagus crowns if the soil is workable.