Gardening tips March
Have you managed to get out in your garden yet with all this damned weather? Its been so pants I have a long list of February tasks still to do (including making my garden sheep proof – bahh). But with a cheek pinchingly fresh first weekend in March behind us already, and some blue sky forecast I’d better get my boots on. You’ll remember last month, I confessed my failures in the garden department? Top tips this month come from the charming Darren Dickey – Head Gardener at one of the six gardens of Cornwall – Trebah Garden – the gobsmackingly awesome garden paradise in Mawnan Smith. Trebah has its very own secluded beach on the Helford River, an amphitheatre and totally spendiferous cafe – an absolute must see if you are down that way.
Over to Darren:
Prune your late flowering shrubs. One of the largest pruning jobs we have at Trebah is the Hydrangea Valley. With over two acres of mostly blue Hydrangea macrophylla this is quite a task taking around three weeks.
General wisdom has it that hydrangeas should be pruned after the last frosts have passed. Therefore in a usual winter March is the best month. We tend to be quite ruthless, removing about a third of the old wood down to the ground. This process helps generate fresh growth from the base and a strong framework, with the end result being larger flower heads. The remaining framework of last Years wood is then cut back down to about three buds. Old plants can be regenerated by taking the whole plant down to ground level but do bear in mind it will not flower that year.
March is also a good time to look at planting deciduous trees. It is always important to prepare the planting hole so as to give your tree the best chance of establishment. It is now thought that a square hole is best as this allows the roots to run through the corners rather than following the circle of the hole making the tree unstable. If the soil is reasonably good it is best not to add anything as it will be more inclined to establish better if the soil is the same as that surrounding the hole. One thing that can be beneficial is a michorrhizal mix of fungi that helps the roots absorb moisture and nutrients.
When planting the tree it is important to first soak the root system for 30 minutes or if it is in a pot water it well before removing it from the pot. If the tree is in a pot and is pot bound, trim the roots. There are a couple of exceptions to this rule as magnolias and eucalyptus resent root disturbance and should not be pruned. With a bare root tree just tease the roots apart to get an even spread. The tree should then be planted to the original pot level or first flare of roots. The soil should then be firmed around the root ball with the heel of your boot. If the tree is large and moves around a lot in the wind it should be staked. Once in place the tree should be checked and watered when needed. Although the surface may seem moist the root system may still be dry. Be careful not to over water especially in moist soil conditions.
Summer flowering bulbs such as alliums, cannas and agapanthus add to the summer display of colour at Trebah. March is a good time to seek out your favourites and plant them in the garden or in pots. Be careful when planting bulbs that are susceptible to wet conditions by making sure the soil is free draining.
Herbaceous borders are also a welcome addition to the summer and will often take you right the way through to the autumn. Now is the time to lift and divide clumps to make way for new additions, bulk up existing clumps or remove those that have reduced in vigour and are flowering poorly. If you are starting out with a new garden this is a good way of increasing the size of your collection, especially if you have a friend that has established plants that they are prepared to divide and pass them on to you.
People often think that bamboos are a plant that does not require any maintenance but this is not true especially if you want to keep them looking good. At this time of the year it is the ideal time to prune out old dead or dying canes, feed with a high nitrogen fertiliser and mulch to help maintain moisture during the summer months. March is also a good time to move bamboos as they establish best at this time of the year. The important things to remember is to maintain a good root ball, by taking as many of the rhizomes as possible, leaving the canes attached and when planting giving the canes some support. This is usually best achieved by creating a goalpost wooden frame and then tying the canes to it until the plant has established. Watering is also crucial and the plant will have to be watered on a regular bases, especially in dry conditions, continuing right the way through the summer if necessary.
Open daily, all year round. Trebah Garden, Mawnan Smith, TR11 5JZ 01326 252200