DISTANCE EDUCATION COURSES The following are our most popular distance education courses in General Gardening. Click on the course of interest for further details:
For the serious Home Gardener: HOME GARDEN EXPERT COURSE Entry Level Courses for a career in Horticulture: HORTICULTURE I (More students have started a career in horticulture with this than anything else we offer, since 1979)
FOUNDATION CERTIFICATE II in HORTICULTURE (Awarded by the RHS, accredited UK qualification introduced in 2009, promises to be the premium entry level qualification world wide).
Entry Level Certificate:
CERTIFICATE IN HORTICULTURE VHT002 (previously C12CN002, established in Australia since 1995 and adopted by schools in Bermuda, the UK and the USA). Graduates of this course have an outstanding track record for developing careers in all sectors of horticulture throughout the world.
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SOIL TEMPERATURE
The rate of absorption of water and nutrients is affected by the temperature of the soil. Too much heat or cold will slow the whole metabolism down. Soil temperature is not always the same as atmospheric temperature. Mulching a plant, or adding organic matter to the soil will even out (or lessen) the fluctuations in soil temperature. As with most organisms, plant roots will grow within a particular range of tolerance which will vary from one species to another.
How to Improve Soils
Organic matter plays an important part during the formation of aggregates and also in their stabilisation. The roots of plants, soil micro-organisms and earthworms all help to form aggregates.
Roots probably play the most important role in forming aggregates. The movement of roots through the soil, their expansion during growth squeezes soil particles together… The drying of a tube of soil around each root makes the soil stress and strain this in turn causes the clay and mineral particles in soils to line themselves up with one another.
You can see the importance of this interaction when you consider that the particles in stable aggregates are held together in part by:
Chemical bonding of inorganic materials such as iron, aluminium oxides and silica
‘Skins’ of clay around the aggregates
Molecules of organic matter
To help improve soils it is important to:
Add lots of organic matter to all soils – composted kitchen scraps, weeds (but not the seed heads), lawn clippings, sawdust, straw…anything that was once living and can be broken down by soil organisms.
If your soil is sandy, add lots of decayed organic matter and cover the soil with mulch.
If your soil is heavy clay, dig in sand and organic matter. Adding gypsum or products like Clay Breaker will help to open the soil and improve drainage.
Add earthworms to the soil, but make sure they have enough organic matter to encourage them to stay.