March is the beginning of spring with longer days which means there’s lots to be getting own with in the garden. However, don’t forget that the weather can also have a more wintry feel with cold winds and low temperatures. Stick to sowing indoors on a bright windowsill or in the greenhouse and don’t be tempted to put tender plants out just yet.

Keep your flower garden sparkling

• Tidy tatty plants: cut back old stems and foliage to just above the ground, taking care not to snip off new growth. 
• Refresh containers:  check over planters, window-boxes and hanging baskets. Pick off dead or damaged leaves and flowers. Scrape away around 2.5 cm of compost from the top and replace with fresh compost. 
• Prune roses: March is your last chance to prune roses, but avoid days when frost is forecasted because the pruned stem may split. Prune to produce an open-centred plant for good air circulation and to encourage new growth.
• Prune fuchsias: cut back to one or two buds on each shoot to encourage a bushy growth.
• Cut back buddleias: cut back last year’s growth to short stubs, just above healthy buds or new shoots, to encourage strong and floriferous regrowth.
• Deadhead daffodils: snip developing seed-heads off so the plant directs its energy and nutrients back into replenishing the bulb. Leave the foliage in place as it will also feed the bulbs.
• Cut back cornus: and other shrubs grown for their colourful winter stems to encourage new stem for next winter. Cut them right back to their base. 
• Cut back hydrangeas: as new shoots are starting to develop, it is time to give hydrangeas a trim to encourage flowering and new growth. Prune off the old flowers to the first healthy pair of buds below. On large and older plants cut out stems down to the base to encourage fresh growth.
• Penstemon: pruning back hard annually is recommended to avoid them becoming woody and leggy. It is best to wait until towards the end of the month or the beginning of April when there is no risk of frost. 

Preparing for colourful and wildlife-friendly plants

Fertilise and mulch your borders: mulch the surface with a 3 to 5 cm  layer of organic matter. It will improve the soil help to suppress weeds and trap moisture in the soil. 

Sow half-hardy annuals: zinnias, cosmos, nicotiana, marigolds, wildflowers….sown indoors in seed trays or plug modules by March or April will start flowering in June. 

• Use peat-free, seeding compost. Fill the seed tray with compost and level the surface by running a piece of wood over it to scrape off the excess. 
• Depending on the size of the seeds, either sprinkle then in a very thin layer or push the seeds one by one. 
• Sieve compost over the seeds and label your trays so you know what is growing.
• Using a watering can with a very thin rose head, gently water the seeds. An alternative, known as bottom watering, is to stand your tray in a shallow tray of water to properly saturate the compost. If using this method, pay close attention to how the tray feels, in terms of weight, once saturated (when the surface of the soil is moist) and use this as a reliable gauge for future watering.
• Cover the tray or plug modules with a clear piece of plastic, to maintain an even temperature and to keep the soil moist. Or use a bespoke propagator that has its own plastic lid. Place in a warm place indoors but not in direct sunlight.
• Remove the plastic cover as soon as the seeds have germinated. The young plants are ready to be “pricked” out when the second pair of leaves emerges. 
• Pricking out seedlings: handle them only by their leaves, not the stem. Fill a new tray or small pots with compost and plant seedlings about 5 cm apart, burying the seedling up to the base of the first set of leaves. 
• Pot individually: after 2 to 3 weeks the young plants will be large enough to be moved individually into pots or planted outside in well-prepared soil. Don’t allow the soil or compost to dry out and if you are planting outside watch out for slugs and snails. 

Divide perennials and ornamental grasses: early spring is the time to refresh herbaceous perennials and to propagate them. Large mature clumps of geraniums, astrantias or hostas can be split now to make more. Some ornamental grasses need division because they die out in the centre. They should be dug up with the outer vigorous sections replanted and the central dead part discarded.  

• Split plants into clumps that are small enough to handle but big enough to make an impact. Discard any old woody centres. 
• Dig up the clump using a spade an ensuring that you get all the roots. 
• Separate the clumps using and old knife, trowel or spade and replant small sections into their new positions immediately. Water them well. 

Transplant foxgloves: Many foxgloves self-seed around the garden and seedlings often appear near the parent plant. These can easily be transplanted to other areas where they have more space to develop. Try to get as big a root ball as possible. Most foxgloves are biennial and you might not get flowers in the same year that you plant the plants. If you want biennial foxgloves to self-seed around the garden and flower reliably every year, you will need to sow or plant them two years in a row. 

Get dahlias under way:  in the greenhouse or in a frost-free growing space, pot up tubers in peat-free multipurpose composts, with the buds facing upwards. Keep moist and place in a bright location until they are ready to plant out at the end of May.

In the vegetable garden

Dig in green manure grown over the winter. Do this while stems are still soft. Chop up leaves and stems with a sharp spade before burying them in the soil.

Weed vegetable seed beds. As the soil starts to warm up and days get longer, weeds will thrive. Keep on top of them before they have a chance to set seeds and spread. 

Dig compost and well rotted manure into your vegetable beds to prepare for the growing season ahead.

First outdoor sowings: cabbages, broccoli, cauliflowers, kale, corn salad, peas, broad beans, parsnip and turnips, beetroots, carrots, Swiss chard can all be sown from mid-March, directly outdoor. 

Sow seeds indoors: using the technique described above for half-hardy annuals, in seed trays or plug modules, sow, sweet peppers, tomatoes, cucumbers, courgettes, aubergines and salads. 

Asparagus: Weed and mulch asparagus beds. Asparagus has shallow roots so weed by hand to prevent damage. March is also the time to plant new crowns. 

Potatoes: are mainly planted in spring, over several weeks, according to the variety. Seed potatoes chitted in February are ready to be planted  from mid-March when the soil temperature has warmed up to 6-10 degrees. Potatoes like rich, fertile soil, so dig in plenty of garden compost or well-rotted manure.

Rhubarb: mulch with a thick layer of well-rotted manure to keep it healthy and to reduce moisture loss. Take care not to cover the crown.

Raspberry: 

• autumn-fruiting raspberry canes: cut to the ground to stimulate new canes, which will fruit in the autumn.
• Summer-fruiting raspberry: cut the tips of the canes that have grown beyond the top of their supports, cut just above a bud.

Fruit trees: mulch with well-rotted manure or garden compost, taking care not to mound mulch up around the trunk. 

Don’t forget 

Attend to your pathways:  Before herbaceous plants start to tumble onto paths, attend to repairs and scrub hard surfaces as paths can be slippery after winter rain.

Support your early perennials: Now is the best time to put plants supports in place for Delphiniums, lupins and peonies. You can use metal support, or recycled hazel, willow or birch prunings.

Resume mowing: give your lawns its first trim of the year. Do it on a dry day with the mower on its highest setting for a light trim.

i