Tuesday 27th April 2010RHS Level 2 Certificate in Horticulture 1 Weeds Good and Bad

Tuesday 27th April 2010RHS Level 2 Certificate in Horticulture 2 Weeds Good and Bad Weeds can have both positive and negative attributes with a garden Can you think of any positive attributes of garden weeds? Can you think of any negative attributes of garden weeds?

Tuesday 27th April 2010RHS Level 2 Certificate in Horticulture 3 Positive Attributes Weeds can be: Attractive – such as field pansy and scarlet pimpernel Edible – like chickweed, fat hen, nettles and ground elder Food and shelter for birds, for example teasel, thistles and ivy Food for beneficial insects, for example cow parsley and host to creatures that will eat pests Attractive to butterflies and bees for example dandelion and white clover Useful additions top the compost heap: deep- rooted weeds for example dandelions can bring up potassium and phosphorus for other plants

Tuesday 27th April 2010RHS Level 2 Certificate in Horticulture 4 Good Enough to Eat Some weeds are very good to eat Late april to the end of May is the best time to make nettle soup, using just the freshest new growth Dandelion leaves are good in salad Ground elder was originally grown as a vegetable crop Wild sorrel makes a good sauce Horseradish, which can be one of the most intrusive of all weeds, is essential to a rib of beef

Tuesday 27th April 2010RHS Level 2 Certificate in Horticulture 5 Positive Attributes Weeds can be: Weeds can act to: Prevent soil erosion Prevent nutrients being washed out of the soil Deep rooted weeds break up the soil in turn providing good drainage

Tuesday 27th April 2010RHS Level 2 Certificate in Horticulture 6 Negative Attributes Weeds can be: Spoil the appearance of beds and borders Overwhelm other plants smothering them with vigorous growth Compete for soil moisture and nutrients Reduce yields of fruit and vegetables Make harvesting more difficult Act as host plants for pests and diseases

Tuesday 27th April 2010RHS Level 2 Certificate in Horticulture 7 Weeds as Hosts to Pests and Diseases Groundsell host to rust Fat-hen may act as a host to insect pests including the mangold fly and black bean aphid

Tuesday 27th April 2010RHS Level 2 Certificate in Horticulture 8 Weeds growing are a useful indicator of the nature and condition of your soil. Sorrel and plantain point to an acidic soil Charlock and poppy thrive on lime soil Chickweed is a good indicator of a neutral pH Nettles, ground elder, fat hen and chickweed point to a soil high in nitrogen Silverweed and greater plantain will grow on very compacted soil Creeping buttercup, horsetail and silverweed point to a wet soil with poor drainage