Gardening jobs for March

The gardening season is starting properly now, despite the cold nights.  There are some early spring jobs to be done such as trimming back deciduous grasses, and if evergreen grasses are looking tatty, you could give them haircut to tidy up too.  Fresh growth will be starting at the base.

Other evergreen monocots such as Liriope muscadine and Phormium can also be kept tidy by pulling or cutting old a dead leaves off from the

Early spring pruning:

Dogwoods (Cornus) and willows (Salix) grown for their colourful stems in winter are cut back now: willows can be cut back hard every year, but some cornus is not quite so vigorous and can be done every other year or less. Buddlejacan be cut back hard too to keep it under control.

You can start pruning Hydrangeas, taking out old flower heads and any other growth can be cut back to a third. Remember though that any late frosts will hit the new leaves and buds hard, so if you are in a frost prone area it might be better to leave pruning till later. If they do get hit by very late frosts like last year, don’t worry, they will come back and just flower a bit later than usual. Give them a feed to help them recover.

Tidying up early spring flowers:

Cut back the older leaves on Hellebores to allow the flowers room to shine. It will also prevent the spread of the common hellebore leaf blackspot. Make sure you clear up any old diseased leaves and do not add to your composter.

After spring bulbs such as daffodils, hyacinths and grape hyacinths have finished flowering, you can deadhead the old flowerheads. Don’t be tempted to cut back all the old foliage though – the plant needs to put energy back in the bulbs for flowering next year – so just let it die back naturally.

You can also divide clumps of spring flowers like snowdrops or aconites when they have flowered but are still in leaf and replant, and also clumps of polyanthus (Primula x polyantha) or primrose.

Dividing established perennials:

Many summer flowering perennials will be showing new shoots now, so you can lift and divide any large clumps that have got woody in the centre or that you just want to make smaller. This works for plants like Phlox paniculata, Asters(now called Symphyotrichum), Sedum (now called Hylotelephium) and Rudbeckia among others.

If you wanted to divide your Hostas, this is the time to do it before they start into leaf.

Spring planting:

You can still plant bareroot or rootballed shrubs until the weather warms up, and on clay soils, it is often better to leave hedges and tree planting until now.

Roses are best planted now too. We have will have some in stock soon – keep an eye on our website. You should avoid replanting them where an old rose has been before, and incorporate some composted farmyard manure in the soil, as well as using a specific mycorhizzae for roses that will help the roots establish.

Topdressing containers:

This is the time to topdress any permanent pots with fresh John Innes compost. Scrape away the top 5cm of the existing compost in the pot as carefully as possible around the plant, trying not to damage the roots and replace with fresh. If you want to deter slugs you can add a layer of horticultural grit on top.

Turf:

If you want to seed a lawn this year, you should start preparing the ground now ready for sowing in late March/early April. You can of course still continue turfing now.

If you think your lawn needs a bit of a boost, you can feed it with a high nitrogen feed from late March.

Mulching and feeding established plants

As the soil starts to warm up (and the weeds start to grow!) it’s a good time to weed and mulch beds with mushroom compost, composted manure or tree and shrub compost. Sandy soils and loams are done now; clay soils take longer to warm up so better leave until April. Remember mushroom compost will raise the pH of the soil and is not good for ericaceous plants like Rhododendrons.

If you have any weak, damaged or heavily pruned plants, you can feed them with a balanced fertilizer like Fish, Blood and Bone. For newly planted hedges or anything which you want to put on lots of leafy green growth, use Chicken Manure pellets or other high nitrogen feed.

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