Monthly Advice - March Jobs in the Garden

posted this on 18 Jul 2016

MARCH IN YOUR GARDEN march jobs

Hedging 

  • Hopefully you have mulched well around your newly planted - and even established - hedge plants but if you have not, weeds start to emerge this month and next stealing food and water just when young hedge plants need them most. It is easiest to get rid of weeds when they are small, so on a dry day use a hoe to uproot ordinary weeds so that they can die and return their nutrients whence they came. Any perennial weeds (ground elder, bindweed, couch grass) or tap root weeds (dandelion, docks) or persistent blighters like creeping buttercup need digging out properly (some might apply a judicious dose of glyphosate) and perennial weeds should not be added to the compost heap. b. A good mulch once the weeding is done helps to suppress seeds that have not yet germinated and also traps winter moisture before temperatures rise and the soil dries out. If your hedge is by a wall or close to tree roots and the soil is dry, water really well before applying your mulch.
  • It is still cold, but once the Met Office starts predicting consistently higher temperatures, you can uncover newly planted evergreen hedges.
  • If it does not rain, water newly planted hedging. In the first year of a plant’s life it must NEVER run short of water. To do so may kill it and will certainly prevent it establishing well.
  • Evergreen shrubs only absorb water from the soil when it is about 4-5 degrees centigrade so if you are going to move any evergreens, March is a good time before spring has properly sprung but when there is a little uptake of water to guarantee recovery after the upheaval.
  • Any lepidopterist will have several Buddleja davidii in the garden for their butterflies and March is the ideal time to finish pruning them. Cut out old branches at ground level to allow new growth to come through

Fruit Trees

  • As the temperature rises towards the end of the month, dormant fruit trees begin to take up water from the soil again to fuel them into spring. All fruit trees need enough water to produce a decent crop of fruit so if it has been dry, water around your fruit trees, especially if they are in the rain shadow of a wall or trained up one.
  • Frost remains a hazard for newly opened buds and infant blossom. It is almost impossible to do anything about large trees but if you see a frost forecast it is worth throwing some fleece over bush trees or have some fleece or polythene attached to two posts that you can then stretch out and lean against a wall-trained tree.
  • Indoor nectarine and peach trees need pollinating by hand. For some reason midday is the prime time for pollen to run, so grab your paint brush (in the old days they used a rabbit tail) and dab a little pollen from one flower onto another and so on all through the tree. Do this three times in total over the next 2-3 days.
  • This is a good month to feed your fruit trees with a high potash feed. Make sure that you pull away any mulch, apply the fertiliser, water so that the fertiliser dissolves to become available to the plant, and then replace the mulch.
  • If you had pear midge then launch a pre-emptive strike by using a spray that contains bifenthrin. Spray the whole tree when the buds are white but still.
  • For non-organic gardeners with apple trees that had scab last year, spray towards the end of the month. There are several fungicides on the market but the nearest you get to an organic version is a copper based type. (The sulphur sprays are less efficient.) The first spray should take place when the buds are closed and the second when they are JUST beginning to show the first signs of colour as the buds open. Spray in the evening when there are fewer pollinating insects around. In future raking up the leaves in autumn and burning them helps prevent any re-occurrence. Keep a watchful eye on both the leaves and fruit for signs of scab to catch any symptoms early. You should then minimise your chemical use and get rid of it.
  • March and April are great tree planting months because roots grow so quickly when the soil is warming (most commercial orchards are planted even later, in June). However all that sudden growth does mean that you have to keep them well watered.

Garden trees

  • Not exactly trees but they should have been spectacular shrubs for the last few months are the dogwoods. Whether you have the bright red Cornus alba ‘Sibirica’ or flaming C. sanguinea ‘Midwinter Fire’ or any of the others, March is the time to cut them down to size so that you get a stubby framework. Prune each stem to no more than six inches (15 cms) above the soil. Known as coppicing, this will encourage brightly coloured, whippy, leafless stems for winter interest next year. Cornus flowers are not much to write home about but they are full of pollen so if you are wildlife garden orientated, then cut down half of the stems for you and leave the other half for the bees. Willows can be coppiced in the same manner. 
  • As with fruit trees and hedges, mulch around any ornamentla trees for the first three years of their life to suppress any weeds and to keep vital water in the soil so that the tree roots never dry out. Well rotted compost, spent mushroom compost, leaf mould or a mulch mat will all do the job.
  • Last good month to plant ornamental trees. As always the key things to remember are soil preparation and watering. We have a good video on how to plant a tree here. You won't need one on how to water, but please remember that more trees dies from lack of water in their first year than from all other causes put together. The watchword here is that when you water, do it really well. A quick splash is (worse than) useless.

Roses

  • March is the last (and best) month for planting bare root roses.
  • Many people prefer to leave their hybrid tea and floribunda rose pruning until spring. So, if you think that the frosts are over, prune with SHARP secateurs or loppers so that you make good, clean cuts that heal quickly. Cut to an outward facing bud so that you encourage summer growth away from the centre. Modern bush roses tend to be grafted onto vigorous stock so do not be shy about giving your rose quite a severe haircut. It will redouble its efforts for you as a consequence. And, thin out the centre of the plant if it is looking too busy because the better the shape and the space within the plant, the better your display of flowers and the healthier the plant.
  • Never pruning rambling roses now because you will lose all of their flowers. We will tell you when!

Soft Fruit

  • Autumn fruiting raspberries should have been dealt with by now by cutting them right down to the ground and then feeding them generously with a high potash fertiliser, but if you are leaving it as late as March (slap on wrist!) then make sure that you look out for and protect any new shoots that may be appearing. You should only remove the canes that fruited last year. Take them out at ground level.
  • Briar fruits like blackberries, loganberries and tayberries fruit on last year’s growth. Tie old growth in one direction and new growth in another so that you can make your pruning life much easier next year.
  • If you have any lovely mini Victorian cloches or any large clear plastic container (even if it was the packaging for a supermarket joint) pop it over a strawberry plant or two so that they fruit a little earlier.
  • Gooseberry advice remains the same as in February and involves pruning so that the plant has an open centre to prevent mildew. Unless you grow them in a fruit cage you will need to net your gooseberries against the birds.
  • Blueberry maintenance time….any formative pruning to attain a good, open shape should be carried out in March – see /gardening-advice/growing-soft-fruit/growing-blueberry-plants-in-open-ground for more information. Blueberries that are grown on open ground in an acidic soil and not in a pot should be fed with a lime-free compound fertiliser in March. If your blueberries sulked and grew less than 30 cm last year then it may be worth applying sulphate of ammonia (follow the instructions). Water well with rain water and then mulch.

Climbers

  • In case you missed the February jobs, and since this February has been the coldest month this winter, it is worth repeating that you need to prune your yellow winter jasmine – Jasmine nudiflorum – once the flowers are over otherwise it becomes lanky and unruly. Cut out any diseased or damaged wood and then spread the main branches over the area that you want covered and tie them in to wall supports to make your basic framework. Then on each main branch, shorten the sideshoots to 5cm from the main stem for a sunburst of flowers next winter. Feed and mulch with an organic fertiliser. If you are short on mulch, a stone at the base of the plant will keep the roots cool and damp.
  • Summer flowering jasmine requires a different tactic; here you have to be ruthless and remove complete main stems. Remove as many main stems as you feel necessary to keep the jasmine in its allotted space. Pruning the sideshoots just results in a tangle of foliage making it difficult to see the flowers.
  • Early March is a good time to tidy up the rather grand lady members of Clematis Group 2 or B because their buds should now be well formed and are easy to avoid. In essence you should aim to do as little as possible but taking each stem from the top, work down to pair of really strong and obvious buds and just snip away any unbecoming growth above them. Ideally the clematis should be trained so that you can leave much of the growth in place and only remove any main stems that have strayed and are now in the wrong place.
  • Group 1 clematis like C. armandii or C. montana should get into full swing towards the end of the month – what fun!
  • Overgrown honeysuckle can be brought back under control in March. When a plant has become a complete tangle it is sometimes difficult to see what should come out, so wait for the buds to break and that way you can see which stems will flower and are worth keeping and which can be removed in good conscience. Generally honeysuckles should be pruned shortly after flowering just to keep them to their allotted space.
  • Hydrangea petiolaris, the climbing hydrangea that is so useful to people with problematic north walls to cover, will still have its spent flowers. Remove these to allow the new buds to form and replace them.

Lavender

  • This is the time for ordering lavender plants. Deliveries begin when the weather is right – often from the middle of April, but the best plants for creating a good lavender hedge in the first year are 2 years old and are grown in 1.5 litre pots. They are always in short supply so order early to avoid disappointment. 
  • If you are planning on planting lavender, start preparing the bed now. There are really good notes on how to plant lavender here

Bulbs

  • Some daffodils may be going over towards the end of the month. Deadhead as many as you can so that all of the plant’s energy goes back into the bulb ready to produce more flowers for next year as opposed to into creating a (useless to the gardener) seed head. Leave the foliage intact.
  • You will still be able to plant snowdrops, aconites and bluebells in the green. Any winter flowering shrub or specimen tree will be enhanced by an underplanting of bulbs to draw attention to them. Try looking at focal points in your garden that do NOT have bulbs around them and imagine white, blue or yellow there. 
  • Forced indoor bulbs made a great present over Christmas and the early months of the year but rather than chucking them on the compost when they are over, plant out your narcissi, dwarf irises, grape hyacinths and hyacinths in the garden taking care not to damage their root system. Chances are that with a bit of a high potash feed and a little water they will surprise you next year with another display of flowers. Do not try to force them again though – they will have run out of stamina and it will be a waste of your time. 
  • Not a bulb, but who can resist a sweet pea? So, if you were organised enough to sow some in autumn they can be planted out in nutrient rich soil towards the end of the month and keep them watered well. Equally, if you want to sow them direct it is worth soaking the seed in water for an hour or two before you plant them. An old trick was to make a nick with a knife or use a nail file to weaken the outer skin so that it was easier for the pea shoot to germinate and emerge.
  • The end of March is the time to ponder summer bulbs and add them to your borders or cutting garden. Eucomis, gladiolus, gladioli and many lilies all now come in exciting guises with surprising colours and sizes. They are a really effective and reliable addition to any border.

Olive and Bay

  • Potted olive trees can come out of hiding and adorn terraces, front doors and vistas again. Keep them watered and a little phostrogen once a month will not go amiss.
  • Your bays will need an annual feed and March is the best time to give them a shot of slow release fertiliser to welcome them into the warmer months.

Other Stuff - including soils, lawns, ponds, terraces

  • Chore Bore of the month. Clean your greenhouse glass to maximise the amount of light available for your seedlings. Lots of light leads to strong, sturdy seedlings that will be pest and disease resistant. It is amazing how mucky glass becomes and cleaning it does not take too long. At the same time, consider researching some of the automatic vent openers on the market now. Being too hot can be just as bad for plants as being too cold and the range of ventilation options is now much larger and less expensive than it was. 
  • Store your compost and growbags in the greenhouse so that they are nice and warm when you start using them. 
  • Plants that have been in your greenhouse over winter will have exhausted their compost so feed or repot them. c. Start your tomatoes, aubergines and peppers this month. You can also succession sow lettuce, cabbage and cauliflower in March. You might experiment with mixing some veg in with your herbaceous borders – think carrot leaves next to Hostas, or Ruby chard with Gazanias or beetroot with Begonias… 
  • While on the subject of borders, all of those lovely winter flowering plants like Skimmias, Sarcococcas, Lonicera purpusii, Hamamelis and some Viburnums will finally be going over. Lightly trim any spent flowers and primp into shape where necessary. 
  • Scarifying and removing the thatch and moss from your lawn is another job that is put off year after year. Set aside an afternoon to tackle it. It is immensely satisfying to see how much rubbish you remove from the lawn and it is good exercise to boot! Use a tined lawn rake if your lawn is small or hire a scarifier for the weekend. A few weeks later with a little bit of feeding, your lawn will look quite changed (for the better!).
  • As soon as you notice that your lawn is becoming a little shaggy start your regular mowing regime again. Keep the blades high to begin with. Little and often is the mantra if you are to achieve a manicured lawn.
  • All that ferreting round in multi-purpose compost and whisking out of weeds will wreak havoc on your hands. BEFORE you go out into the garden, run your nails through a bar of soap, put hand cream on and then gardening gloves and you will ameliorate at least some of the damage.
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