April is an exciting and busy month to be a gardener; however the weather can still be unpredictable. Beware of frosts, and keep vulnerable plants and new shoots protected at night if a frost is forecast
Without doubt the star plants of April are members of the ericaceous family, including Azalea, Camelia, Pieris and Rhododendron. Ericaceous plants are known as ‘acid-lovers’ or ‘lime haters’ as they do not like growing in soils that contain lime (Alkaline soil) or soil that has a high pH. If you try growing ericaceous plants in alkaline soils they produce yellow leaves. This is a condition known as chlorosis, and the plants will not grow or flower well, and eventually die.
The main reason for chlorosis is that acid loving plants need plenty of iron, and other soil nutrients, that become insoluble or ‘locked up’ in high pH soils so that the plants can’t absorb them. Breckland soil is unique and variable, with underlying chalk being largely covered with wind-blown sand, resulting in areas that have an acidic top soil but alkaline sub-soil. Often, when planted in our soil, ericaceous plants initially thrive, until their roots reach lime. It is better to grow ericaceous plants in large pots (not terracotta which contains lime) filled with ericaceous compost. Also by growing ericaceous plants in containers it allows you to grow them in the right place in the garden, and you can move the plant to a more visible location when it’s looking its best. The plants listed above prefer a position in light shade, or out of direct sunlight – especially early morning sunlight which can cause the flower buds and flowers to turn brown and drop off.
The other thing you need to ensure fabulous flowers and healthy growth is to feed the plants with an ericaceous plant feed which contains specific nutrients. This can be either granular or liquid. Because Rhododendrons, Azaleas and Camellias set their flower buds from June to August, its essential to keep them well fed during this period. They are also prone to drying out during prolonged dry periods so it is important to keep the compost moist, this is particularly important during the flower bud setting period in summer, if the compost is allowed to dry out the bud set can fail. As our tap water contains lime do not use it to water ericaceous plants, instead use collected rainwater. Dead-heading Rhododendrons after flowering not only makes the plant look more attractive it is also important to prevent the spread of fungal disease and to stop the plant setting seed which will be detrimental to next years flowering. Dead-heading is fairly easy as the central axis or truss will break free from the plant with a simple twisting method between your thumb and forefinger. When dead-heading take care not to damage the growth bud or new shoots directly below the flower cluster as this will also be detrimental to next years flowering.
Here are my other top tips for April:
• Tie climbing plants into their supports
• Lift & Divide congested clumps of bamboos and grasses.
• Pinch out the growing tips of bedding plants such as fuchsias.
• Feed, Weed & Mosskill lawns.
• Sow seeds of marrows, courgettes & squashes indoors in 3 inch pots of seed compost.
Whatever April brings I hope you get a chance to step out into the sunshine and enjoy the season as you tackle this months gardening jobs.
Rachel Sobiechowski BSc (Hons) P&R Garden Supplies, Fengate Drove, Brandon 01842 814800 www.p-rgardensupplies.co.uk