TURNER'S glasshouse may be self cleaning, but the domestic one certainly is not and should be given a yearly cleansing to remove all traces of algae, harmful organisms and over wintering pests. Remove its contents and scrub it inside and out with washing up liquid and a dash of Jeyes Fluid in a bucket of warm water. Use a plant label to scrape under where the panes overlap. Before returning pots to the green house check their insides and undersides for snails, slugs and their gelatinous eggs.
And while you're at it, it's a good time to clear out all the dead pots and seed trays that accumulate in all but the most perfect of gardens. Discard any that are broken or cracked. Scrub the others with the magic solution, above. Put them away.