March can be a frustrating month, keeping an eye on the weather forecast is essential in order that we do not miss the dry days and the opportunity to get out in the garden. There is however, much to do indoors, sorting seeds, pots, labels and planning annual displays.
We often have part bags of potting compost left over from last year and the dilemma is what to do? Should we throw it on the garden or can we use it for potting on. My advice is any open bags should be mixed with compost from the compost heap and used to improve the soil when planting. Compost that has been stored for over six months can go sour, this means that the fertilizer in them deteriorates and especially with soilless composts the organic matter (peat or composted material) can either go mouldy or green. As a born and bred Yorkshireman I am reluctant to just use this up on the garden, instead I prefer to mix it with equal parts of newly bought compost and use it in my containers. If on opening the bag it smells unpleasant then it is best to mix this into the compost heap. Always use new compost for potting on and germinating seedlings under glass, as young seedlings and growing plants are more susceptible to pest and disease attack.
Any fertilizers and feeds from last year should be ok, providing they are not out of their ‘Sell by’ date, and that dry fertilizers have been kept dry. Ideally you should try to use up chemicals and in the year you purchased them as some can lose their effectiveness.
If you have a heated greenhouse, the Pelargoniums and Fuchsias and Dahlias started into growth last year should be showing signs of new growth. It is essential to place them in a light and airy place with a minimum night temperature of 10C (50F), to maintain active growth.
Towards the end of the month there should be enough growth to start propagating. New growth shoots that are about 7.5cm (3inches) long should be removed with a sharp knife just below a leaf joint. Fill a small pot (9cm – 12cm) with cuttings compost (add a little grit sand, Pearlite or Vermiculite, available from most nurseries and garden centres) prepare the cuttings by removing the lower leaves leaving two pairs of leaves at the top. Dip in a rooting powder or gel and using a dibber make a hole in the compost next to the edge of the pot. Insert the cutting and carefully press the compost from the middle of the pot towards the cutting. It is essential that you do not squash or damage the cutting as it will simply rot rather than root. Water the cuttings in and place in a plant propagator or if you do not have one place the whole pot inside a reseal able plastic bag. Once each day open the plastic bag for 10 to 15 minutes then reseal. After about three to four weeks you should be able to see white roots emerging from the drainage holes in the pot. Wait a couple of weeks and then pot the cuttings on into individual pots (9 – 10cm) using fresh compost. They don’t need the propagator or plastic bag now but keep them in the warm greenhouse as they develop.
March is also the busiest month for sowing seeds, give them the same conditions as your cuttings and try to divide your sowing into weekly batches otherwise you could have hundreds of seedlings to prick out at the same time.
If the weather is fine and the lawn is dry enough to walk on start by gently scarifying with a wire rake, any repairs such as turfing and seeding will be done next month, followed by a spring feed.
March is the last month in which you can plant trees, shrubs and perennials that were purchased as bare root plants, if the weather delays planting then pot them up using old compost and plant as soon as the weather improves.
Next month, Pricking out and potting on, pruning spring flowering shrubs, and taking stock in the garden.
Happy gardening,
Martin
York Gate Garden is owned and maintained by the charity Perennial (Gardeners Royal Benevolent Society) which provides advice help and support in times of need or difficulty for people who are working in, or have retired from any of the gardening trades. (Registered Charity no. 1155156). Opening times and further details can be found on our website at
www.perennial .org.uk
