In the greenhouse ​

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• As seed sowing gets into full swing, it's important to know which seed to sow when. It's easy to miss the window for some, like Iceland Poppies, Cobea or snapdragon that need to be started early undercover, and you don't want to sow other seed prematurely and end up with leggy plants (Cosmos, I'm looking at you).
   

• Work backwards from your last frost date and use the info/dates on the packet of the seed to help you figure out the best time to sow what in your region. March is a good time to sow most hardy annuals indoors undercover - you'll be able to sow these direct outside later this month. 
   

• Wait until the second half of the month to sow half-hardy annuals. Most only need to be started off 6-8 weeks before the last frost date.
   

• Pinch out the tips of winter/autumn sown sweet peas to encourage side branching. It's possible to use the tips to propagate more plants - treat them as you would any softwood cutting - just pot them into free draining compost using a little rooting powder to encourage them on their way.  

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Bulbs, tubers, corms & claws

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• Start off ranuculus and anemone by 'pre-sprouting' the corms in a seed tray of 50/50 compost/vermiculite in a propagator or on a heat mat (or put them in a plastic bag in the airing cupboard). Once the roots are an inch or so long, pot them on into 9cm pots or 15-cell trays in the greenhouse. 
   

• If you are intending on taking cuttings from your dahlias this year to increase stock, it's time to wake them up. Put the tubers into 5L pots or a seed tray (depending on the size of the tuber).  It's much easier to take cuttings later if the top couple of inches of the tubers are above soil level, so don't submerge them completely. The pots will need to go on heat mat or propagator in the greenhouse. There's still time to get hold of bare root dahlias if you haven't already. They're still online and in shops, but won't be for much longer. 
   

• Plant any summer/autumn flowering bulbs such as lilies, gladioli, nerine and acidanthera.
   

• Once daffodils, muscari and other spring bulbs have finished flowering, deadhead any you haven't already cut. Allow the leaves to die by naturally to allow photosynthesis to occur. 
   

• Lift and divide snowdrops to increase your stock - ideally done just as the flowers go over -  known as 'in the green'.

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​In the garden

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• Weather & soil conditions permitting, continue to prepare beds by clearing the last of any dead foliage from perennials (if you haven't already) and pulling out any weeds. Perennial weeds are much easier to tackle now as the roots won't have had a chance to properly take hold yet. Once clear, mulch with a thick layer of homemade compost or manure.
   

• Make a special effort to prepare the area where you will plant your sweet peas - they will flourish the extra effort of digging in plenty of manure and general fertiliser. Install the support system prior to planting the plants out later this month. 
   

• Start to plant out any autumn-sown hardy annuals like cornflowers, ammi, wild carrot and orlaya. Acclimatise them well to conditions outdoors by 'hardening' them off properly to give them a fighting chance once they're out in the garden.
   

• Get the last of the overwintered biennials like foxgloves and wallflowers in if you haven't already. Hold back on any planting out for a few days if the ground is very wet or a very cold spell is forecast. A feed of seaweed should keep the plants happy if you are held up in getting them out.
   

• Create plant support and structures from willow/hazel. Use poles cut back in mid winter whilst the plant was still dormant. Anything cut later will sprout once in the ground. 
   

• Deadhead hydrangeas before new growth begins to show. 
   

• Divide any congested clumps of perennials such as Delphiniums, sedum (hylotelephium) or ornamental grasses.
   

• It's a good time to buy small pots of perennials to plant out as they are cheap at this time of year - they will bulk up quickly if planted now and offer good value for money. 
   

• Prune any roses you haven't had a chance to tackle yet, but leave any ramblers until after they have flowered in the summer if you fee they need taming a little.   

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Last call: 

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• It's the last chance for ordering and planting out bare-root plants as the season will come to a close towards the end of this month.