March gardening tips: jobs to do and what to plant

18 February 2021

Find out what needs doing in the flower bed and vegetable patch in March, plus what you can plant now and what you need to do to get your garden ready for summer.



What to plant in March

Flower seeds to sow in March

Hardy annuals can be sown in trays indoors or under glass now but unless you live somewhere mild it’s a bit early for half hardies.

There’s nothing more depressing than seeds that fail and these should deliver: honeywort cerinthe major ‘purpurascens’, cornflowers, borage (great for bees and decorating drinks) and viper’s bugloss (also great for bees and for butterflies).

If seed trays have been stored somewhere outdoors or weren’t washed when you put them away give them a good wash and brush up with hot soapy water and don’t think you’ll save money by using old compost or earth – you’ll regret it when seeds shrivel and die.

Use large trays, fill with seed compost to near the top and water with a can with a fine rose or stand in a sink until the tray’s absorbed moisture. Don’t use water from the butt as this can lead to disease and try to use lukewarm rather than freezing cold water.

Sprinkle over seeds as sparingly as you can manage and use a sieve to sprinkle of a light layer of dry compost. Sit somewhere light and neither too hot nor too cold. You want an even temperature around 18C or 64F. Some people like to cover the tray with glass or a clear polythene. You should see results in a week or two.

Once the seeds germinate remove any covers or you’ll get condensation and rot. Whilst you are waiting watch that the compost doesn’t dry out but don’t overwater either. Aim for a consistently moist compost.

It's your last chance to plant out summer flowering-bulbs like lilies, as well as any forced bulbs you might have had indoors over winter, such as daffodils and hyacinths, if you haven't already.

Vegetable seeds to plant in March

Hardy crops can be planted out in March, although those in the very north of the country should wait until the end of the month or even early April, depending on the weather. Hardy vegetables include broad beans, peas, spinach, garlic, onions, radish, Swiss chard and beetroot. Sow in short rows at weekly intervals to ensure a steady crop over summer and autumn.

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Garden jobs for March

Feed roses

If you haven’t already done so give roses their first feed of the year. Use a tailored rose feed as they need the correct mix of nutrients. And don’t think you’ll be doing them a favour by over feeding. You’ll end up with too much sappy soft growth that makes them less able to withstand pests. Feed again in April/May and, if you want, they can have a final feed in July but no later or that soft wood will make them vulnerable to winter cold.

Mulch borders

What you mulch with will depend both on what you have to hand and on what condition your soil is in. Hard clay soils can be opened up by digging in or mulching with composted bark or well-rotted manure or grit. Avoiding walking on the soil which only compacts the soil even more, by spreading your weight across a board. Sandy soils also benefit from annual applications of well-rotted manure, home compost and other organic matter.

Find out more about mulching to save moisture

Deadheading and pruning

Cut off old hellebore leaves to stop disease and to show off fresh new flowers.

Dead head daffodils by cutting flower stems to the base but let foliage remain to help build up energy stores in the bulb. This reduces the chance of them coming back blind (without flower) next year. Without deadheading the plant will put all its energy into producing seeds instead. However, wild varieties such as Narcissus obvallaris can be left to spread by self-seeding. Daffodils will also benefit from a liquid feed every other week and try to avoid them drying out for a month or so.

Prune outdoor fuchsias back to one or two buds on each shoot, ie about four inches above ground level cutting to just above a pair of buds. This will encourage new shoots.

Cut back cornus and salix which are grown for colourful winter stems .

Deadhead and prune hydrangeas before the sap starts to rise.

Prune winter-flowering jasmine, cutting last year’s growth to a good sideshoot.

Plant a clematis

March is a good time to plant a summer-flowering clematis. These climbers race away now and those that flower after Midsummer’s Day (21 June) produce lots of smaller flowers from top to toe. Classic varieties include 'Étoile Violette', ‘Polish Spirit’, and ‘Betty Corning’. Pruning’s easy, just cut them back to the lowest buds in mid-February and they won’t suffer from wilt.

Mow the lawn

Once your lawn has had a few weeks of new growth you can give it its first mow of the year, if it isn’t wet or frosty. Make sure your mower blades are in good condition to avoid tearing the grass, and very lightly rake the grass to remove debris. Mow with the blades at their highest setting. Apply a spring or summer lawn fertiliser towards the end of the month according to pack instructions.

Chit potatoes

If you haven't already started your potatoes start chitting them now. Large egg trays left somewhere bright are perfect for this.

Spruce up garden furniture

Time to spruce up your wooden garden furniture for the year ahead, because the weather’s improving day by day. Choose a dry day and brush down any wooden chairs and tables before applying Ronseal’s Garden Furniture Restorer or similar product. It’s suitable for all hardwood furniture and it’s pet and plant-friendly. Stir the tin, apply the gel with a brush and leave for 15 minutes, before scrubbing and hosing it off. Leave it for a day and then apply furniture oil, which comes in teak, clear or oak. They also do garden paint in 24 tasteful shades, for pots, brick, wood, terracotta or metal.

Clear up the vegetable patch

If you’re keen to get started now’s a good time to weed beds, clear away old debris, netting, bean supports and the like and to stand back and survey with pleasure a clean, raked surface.

Dig a bean trench

A wheelbarrow of part composted kitchen waste can be wheeled to where you want to grow any greedy plants like beans. Dig a trench a couple of feet deep, fork over the base to loosen the soil, tip in the organic matter and mix in the previously dug out soil. If you’re me it’s worth putting in markers, or even erecting your bean poles, so you don’t forget where the treasure’s hidden when it comes to planting time. Leave a good couple of weeks before you sow your seeds.

Divide perennials

This is the key moment for dividing clumps of perennials because it’s possible to break off the outer, vigorous pieces and replant them straight back into the soil with a dusting of blood, fish and bone. Only select clumps with sparse middles, or ones with perennial weeds, or clumps that need reducing in size. Lift them with a fork and most will pull part into hand-sized pieces (others may need chopping with a spade).

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Tending to your houseplants

When you see growth starting again it's time to check your houseplants. Some may just need a tidy up, clearing away dead leaves and debris and a bit of a prune to get it back into shape. If roots are appearing through the base it’s a sign they need repotting. If you cant see the roots, but it’s a while since they were repotted, try to loosen the plug of earth out of the pot and see if the roots are circling as if desperate to get out. If so it’s time to repot. 

Ideally, water plants a few days before repotting. Use washed pots, one size larger than the existing pot, and fresh clean potting compost – whichever is correct for the plant. Some plants like a lighter mix so I tend to mix up my own soil for each plant using a combination of potting compost, sand and perlite as necessary. 

You can add water retaining gel granules if you like and some plants benefit from a topping of grit.  

If the plant’s just not going to come out of the pot you can try to eke out a little more time by top dressing. To do this carefully scrape off an inch or so from the top of the old soil, avoiding damaging the roots, and replace with fresh new potting compost. Water pots well and drain. Avoid putting newly repotted plants in direct sunlight but let them recover slowly. 

After a week or so they should be nicely settled in.

Visit our gardening section for more gardening tips and advice, including guides to maximise your spring garden.

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The opinions expressed are those of the author and are not held by Saga unless specifically stated.

The material is for general information only and does not constitute investment, tax, legal, medical or other form of advice. You should not rely on this information to make (or refrain from making) any decisions. Always obtain independent, professional advice for your own particular situation.