There is usually more to do in the garden in March than the previous two months as the weather is improving and growth is getting underway. The achievements you make in March will pay dividends right through until the autumn.
Soil
Rake any remaining autumn leaves and composts or work into the soil. Dig in organic fertilizer.
Vegetables
Outside
Some vegetables can be planted at this time of year – onions, shallots, garlic and early lettuce. Sow onions 12mm deep and 200-300mm apart.
Sow spinach in a sheltered border preferably with a southerly aspect.
Plant mint
You can make a new rhubarb bed now or transplant old roots from one part of the garden to another.- make sure the ground is well manured first
A few roots of horseradish are always useful plant in an out of the way part of the garden – it is an extremely difficult plant to get rid of once established.
Sow stump rooted carrots outside choose a sheltered place- main sowings will be next month
Cauliflowers that were raised from a September sowing in a frame can be planted outdoors if they are hardened off.
Make first sowing of outdoor peas and early potatoes in mid to late March.
In the Greenhouse
During the month, seedlings such as cauliflowers, lettuces and tomatoes raised in the warm greenhouse or frame last month will be ready for pricking out (when they have made two true leaves). Lift and dibble them 50mm apart, water freely and shade for few days.
Several vegetables that you have already sown will need to be resown to provide a succession. Radishes – should be in a frame as they need to grow rapidly. Mustard and cress can be grown freely in the frame or greenhouse. Lettuce can be grown in the greenhouse early in the month and outdoors later in month.
Sow broad beans, cucumbers and celery in the greenhouse.
Sow herbs such as thyme, sage and marjoram in a frame or greenhouse.
Onions and leeks sown in the greenhouse in January and vegetables sown in early February can be moved to a frame where they can be hardened off ready for planting outdoors in April.
Pot early tomatoes and make further sowings in the greenhouse.
Sow aubergines and capsicums (peppers) in a propagating case.
Plant melons that have been raised in greenhouse in February.
Fruit and Berries
Outside
Newly planted apple and pear trees will need a formative cut – pruning accelerates the budding process.
Identify the main shoots and cut off any competing stalks or branches right back to the trunk – establish which will be the leaders that will form the top of the tree.
March is an ideal time to prune sensitive trees like peaches. Shorten the main spur and remove any competing shoots. Cut off any competing shoots on the branches and remove all growth from the inside of the framework and any dead shoots.
Remove upright shoots as they will grow rapidly but tend not to add to your fruit crop as the fruiting wood will develop from the horizontal shoots.
Protect early fruit blossom – outdoor peaches and nectarines should now be coming into flower – if you can, protect these with fine mesh in front of the trees.
In the Greenhouse
Peaches, nectarines and apricots in an unheated greenhouse will come into bloom early in the month.
Flowers and Shrubs
Outside
Summer and autumn flowering ornamentals should be pruned in March. Leave spring flowering ones.
Thin out summer flowering plants such as perennial shrubs – some can be left such as laburnum and magnolias.
Continue to prune roses. Remove any protective pine needles, straw or leaves as they will inhibit the growth of the plants.
Roses should be fertilized at the end of March – loosen up the ground around the base and work in organic all purpose compost or special rose fertilizer and water.
Roses can also be planted in the spring
March is usually the best time to transplant most herbaceous plants – try and do on good days early in the month as persistent rain can hold you up later. Split by hand if possible but use a small fork for very tough clumps. Replant with a spade or a trowel and work some fine dry soil around to thoroughly firm in the plants.
This is a good month for transplanting snowdrops.
Plant summer flowering bulbs.
Special rhododendron fertilizers can be used to enhance your flower crop.
Spread bone meal or compost around plants and begin planting new perennials preferably when the sun is not shining directly on them. Place taller plants at the back and shorter at the front.
Add organic compost and leave room for them to grow.
Many are sold in containers – if roots are dry give a good water first and place them in the ground to the same depth as the container. Press earth around and give plenty of water as new plants are almost always thirsty.
Some perennials such as peony roses, irises and bleeding heart are not suitable to plant in the spring so check first.
Ferns can be planted in shady spots and they like a layer of bark mulch or wood chips. A good range of greens is available.
Sow sweet peas outside - about 25mm deep and 50-75mm apart in rows 250mm apart.
In the greenhouse
Take cuttings of bedding and greenhouse plants such as heliotrope, marguerite, fuchsia and pelargonium. As soon as they are long enough, sever them cleanly immediately below a joint and then insert them in well drained boxes or 100mm pots filled with a sandy compost.
If you have a heated propagating case, this is ideal but otherwise keep in a shaded place.
Stop early carnations that were rooted in December and January – the tops are broken off which makes the plants produce sideways growth, usually at about the seventh joint.
Perpetual flowering carnations will need to be potted on to 75-100mm pots. You can continue to pot new cuttings of chrysanthemum and carnations
Early March is a good time for potting summer and autumn flowering plants and all plants that are grown principally for their foliage such as palms and ferns.
Many herbaceous perennials and rock plants can be raised from seeds sown at this time of year in a frame or unheated greenhouse including delphiniums, lupins, perennial gypsophilias, perennial statices, coloured primroses and polyanthuses, violas and pansies.
Sow half hardy annuals in a frame if you have no heated greenhouse
This is also a good time to sow seeds of cacti and succulents
In a heated greenhouse, cannas and dahlias can be started by planting the roots. Begonia and gloxinia tubers that were started in January can also be potted.
The greenhouse will now be filling with many more seedlings of vegetables, half-hardy annuals and greenhouse plants needing pricking out and young rooted cuttings.
The temperature should be kept at around 13-16 deg C and ventilation is needed – increase top ventilation on bright days as temperature can rise rapidly.
Roses in pots started in the greenhouse during January or February will benefit from an occasional spraying with a greenfly killer.
Lawns
Lawns will look tatty at this time of year – remove moss, dead grass and leafy moulds by raking or scarifying the surface.
Top dress the lawn with ‘controlled release’ fertilizer that will last until the autumn. Water with a sprinkler.
March is also a good month for turf laying and for repairing bare places in lawns – choose a day when the surface is dry enough to be walked on and can be broken down reasonably well with the fork or rake. See our section on Lawns for more information.
Building
March is a good time to paint or stain fences before climbers start to grow up them.
Other Jobs
Weed all paths and patios.
Clip ivy on the walls
Add fresh compost to plant containers
Beware of slug activity as the temperatures rise. They can strip young plants and new growth, doing irrepairable damage.