The soils at Dairy Flat are limestone based, and funny as it may sound, are deficient in lime or acidic. We apply lime at the rate of 1 cup to 2 plants on the high side of the beds to allow water to wash it in. If the plants are in the ground at this stage the lime can burn the foliage so care is needed.
The use of sawdust/shredded plant material as a mulch during the growing season means the soil uses a certain amount of nitrogen to break up the rotting matter. So at the start of the shoots we usually sprinkle Urea at a rate of 1 handful per 3-4 plants on the high side of the plant.
We apply 15% Potash Super North S. (Potash, superphosphate and sulphur) on the farm grazing areas as a result of soil sampling - so we also apply it to the dahlia beds. This is usually a sprinkle after planting and one more before Christmas when the weather looks grotty - but before the mulch goes on.
A list of suitable sprays are available from your local garden centre.
HOMEMADE REMEDIES - from Auckland Dahlia Society
Red Spider Mites
Red Spider Mites dislike humid conditions. Use a milk spray for mites and eggs.
1 cup buttermilk, 4 cups flour, 5 gallons water.
Mix well and use daily until condition clears.
White Fly + Red Spider - Witches Brew
375 ml Sunlight Liquid, 100 ml Scrubs cloudy amonia, 50 ml citronella, 1 cup washing soda disolved in boiling water. Add to 5 litres water.
Use at 100 ml to a litre of water.
1 Tblspn vinegar, 1 Tblspn Janola, 1 Tblspn Sugar, a few drops of detergent.
Mix in a bucket full of water and spray on the plants.
USE ONLY AS DIRECTED - NOT INTENDED TO REPLACE A REGULAR SPRAY ROUTINE. DAHLIA HAVEN ACCEPTS NO LIABILITY FOR DAMAGE/LOSS INCURRED AS A RESULT OF USING THESE SPRAYS.