Clumber Gardener - April 2018

Chris Margrave Head Gardener

We caught up with our Head Gardener Chris Margrave to find out what's happening in the Walled Kitchen Garden this month and what you need to be doing in your gardens for the season ahead.

Award Winning Hyacinths

The changeable spring weather in March and April really put our gardens to the test and it is interesting to note which varieties have fared best given the combination of bitterly cold winds, snowfall and heavy rains interspersed with mild, sunny spells.  Some spring flowering bulb varieties have performed better than others. This is an area where the plant trials work carried out by the Royal Horticultural Society (RHS) can prove very useful to gardeners wanting to make an educated choice about which varieties to plant.  It doesn’t matter how good a grower you are, if you choose the wrong variety, you may be disappointed with the results, in spite of your best efforts.

RHS trials cover the full range of garden plants, assessing, for example, hardiness, pest and disease resistance and flowering in ornamentals or yield in vegetables and edible fruits.  In 2012 the RHS conducted a trial on the performance of hyacinths, the aims of which were to draw attention to the range and colour of their flowers and to award the Award of Garden Merit (AGM) to the best performers.  The trial included some newly raised hyacinths and these are now becoming available for gardeners to buy.

Eight varieties gained the AGM in the trial.  When you’re choosing varieties to plant this autumn, look out for the following (and remember to take care, as the bulbs can aggravate skin allergies):

‘Fairy White’ is described as outstanding with clean, white, weather-proof flowers.

‘Dynasty’ has good form, standing up well and holding its pink colour well.

‘Aqua’ is a good, clear blue and stood up well to the weather.

‘Royal Navy’ is a lovely deep, rich blue.  Every floret is a real double.

Further information about the AGM winning hyacinths and other trials can be found on the RHS website 

Many of the hyacinths we grow in our gardens date from the 19th century.  They have deservedly stood the test of time and others, such as the early flowering blue ‘Ostara’ and yellow ‘City of Haarlem’, have been awarded the AGM from earlier plant trials and assessments.  The classic spring bedding combination is to grow hyacinths with other bulbs, such as tulips, and bedding like the low growing bellis daisy, winter-flowering pansies or forget-me-nots.  For knock out scent, grow them with wallflowers.

When you’re next visiting a garden centre, take a look at the label on the plant.  Some may have the trophy symbol which indicates the variety has been awarded the AGM.  This is across the board and could be a variety of fruit, shrub, hardy perennial or tender orchid, as well as a bulb, like the hyacinths.

Jobs for the Month - May

May is often the busiest month of the year as daylight length increases, temperatures rise and the danger of frosts subsides.

Hardy annuals can be direct sown into prepared soil this month to provide easy colour.  Candytuft, pot marigolds (calendula), love-in-a-mist (nigella) are all suitable, as are red field poppies. 

Sow carrots, beetroot and salad leaves such as lettuce and rocket.  For best results, water the base of the seed drill before sowing your seeds.

Harden off tender and half hardy plants such as summer bedding, summer container plants and half hardy vegetables such as sweet corn and runner beans, by gradually acclimating them to cooler, outdoor conditions.  They can be planted out when the danger of frost is past, usually towards the end of the month.    If a late frost is forecast, cover transplants over-night with horticultural fleece.

Water new plantings in dry weather.  A thorough soaking to the soil around the plant is better than a superficial spraying to leaves and the soil surface.  Watering in the evening will make best use of water.

On dry, sunny days keep annual weeds in check with a hoe.

Continue staking taller growing herbaceous perennials such as delphiniums.