The March Garden
Thoughts and advice for the gardener in March.
Hello,
The month of March stretches ahead of us, offering the opportunity to get out into the garden again and although the month is the official beginning of spring, but it can be very cold at times so keep an eye on the weather forecast and wait to do jobs if conditions aren't right.
The clocks also go forward this month on the 30th March so the lengthening daylight hours also help plants to really get growing. Spring bulbs take centre stage in the borders and in patio pots, rewarding your efforts for planting them last autumn.
Roses:
Prune bush and shrub roses this month, climbers care usually pruned in the autumn so that they can be tidied and tied for the winter months. The main reason for pruning roses is to build a healthy framework of shoots that will produce a good display of flowers.
Thinning over-crowded growth allows light and air in, so there will be a lesser chance of problems with pests and diseases. Use a sharp pair of secateurs, cuts must be clean and not ragged.
Remove any dead or unhealthy wood.
Then check for any shoots or stems that are rubbing against each other and cut them both out.
Prune the rose back to the required height. Always pruning to an outward facing bud. The main rule with pruning roses is that the harder you prune the more vigorous the subsequent growth will be.
Clear up rose pruning’s carefully, its best to dispose or burn them as they can harbour disease. Then mulch around the rose with well composted farmyard manure.
Hardy annuals can be sown in pots or modules to provide colour in the garden. In mild conditions you can sow directly outside.
A spring sowing of sweet peas can be sown outside this month. If you have sown sweet peas last autumn encourage them by placing them in a sunny position, perhaps on a high shelf in the greenhouse that gets plenty of light.
Sow summer bedding plants in a heated propagator or under glass.
Watch out for perennials putting on growth, which may need support by the end of the month.
Check whether containers need watering. Even at this time of year, they can dry out. Pots that are sheltered by buildings can miss out on any rainfall. If in doubt, check the compost at a hand’s depth to see if it feels dry. Aim to keep pots moist, not wet, and don’t let them dry out.
Pots and tubs benefit from topping up with fresh John Innes compost. Old compost can be removed and replaced with new if there is not much room for topping up. Some grit will also deter slugs.
Feed borders with a general-purpose fertiliser at the manufacturer's recommended rate.
Early spring is an ideal time to plant herbaceous perennials, including Geranium, Astrantia and Oriental poppies.
It is time to start thinking about your lawn:
This is the time of year when grass starts to grow vigorously. The lawn will need your attention now, particularly if has not had any attention in the winter.
From the middle of the month (again weather dependant) the lawn should be raked and mowed. Rake vigorously, first in one direction and then another, to get rid of any accumulation of dead leaves and moss, then brush over with a stiff yard brush to scatter any worm casts. This will also bring the blades of grass upright ready for mowing.
With grass growth just starting, mower blades should be set fairly high at about 2.5cm (1 in). You can lower the blades later when growth is more rapid.
Now is a good time to trim and redefine lawn edges, using a sharp, half-moon edging tool.
Towards the end of March or early April (weather / warmth dependant) give the lawn a good feed with a special compound lawn fertilizer that contains a high proportion of nitrogen. This will provide a good green sward that will be strong enough to withstand any drought later on. Feed the lawn on a warm day after there has been a spell of rain and the soil is moist, but the grass dry. (If more rain is forecast, postpone the operation.) Make sure you distribute the fertilizer evenly; special hand distributors are available-or you may end up with scorched and patchy growth.
Plant summer-flowering bulbs. Rather than just popping the bulbs in, the preparation of the soil to provide good drainage will help in preventing the bulbs rotting, especially in the soils we have in this area, digging in multipurpose compost mixed with horticultural grit is an idea solution. Anemone tubers need particularly well-drained soils.
Indoor forced bulbs that were in the house for winter displays, but which have now finished flowering, can now be planted into the garden, taking care not to disturb the roots.
If you have not done this yet, cut back ornamental grasses and other perennials left for winter interest if you have not already done so. Even if they still look good, you need to make way for the new growth.
Cut off old leaves of hellebores that produce flowers from ground level to expose the flowers and remove possible foliar diseases such as hellebore leaf spot.
Divide and/or plant bulbs-in-the-green, such as snowdrops and winter aconites, if not done in February.
Divide clumps of herbaceous perennials that you want to propagate, those that have become too large for their allotted space, and those that are flowering poorly or have lost their shape.
Divide hostas before they come into leaf.
Divide hellebores and polyanthus-type primulas after flowering.
Continue to deadhead winter-flowering pansies and other winter bedding. Pansies will carry on into the spring and even to early summer, if attended to frequently.
Deadhead daffodil flowers as they fade but allow the foliage to die down naturally.
Herbaceous perennials infested with couch grass and other perennial weeds should be lifted so the weeds can be removed. Improve the soil by digging in organic matter before replanting.
Clear up weedy beds before mulching. Mulching with a deep layer of organic matter helps to condition the soil, suppress weed growth, insulate plant roots from temperature fluctuations, and conserve soil moisture during the summer.
It is best to get plant supports in early, so that the plants grow up through them, covering them discreetly. Adding rigid supports afterwards usually looks unattractive and results in bunched stems lacking sufficient ventilation. Criss-crossing strings from hidden or decorative posts work well, allowing stems to grow up in the gaps between strings.
Watch out for downy mildew and black leaf spot on winter pansies. Remove any infected leaves and destroy badly affected plants.
Remove dead leaves from around the basal rosettes of alpine plants to prevent rotting.
Top dress spring-flowering alpines with grit or gravel to show off the plants and help prevent rotting around the neck.
As always, I wish you happy gardening.
Rog
The writer, Rog Leppard, is a professional gardener with his own gardening business and a gardening writer, based in Ashurst Bridge.