Gardening With Reduced Water

March 26, 2019

This was one of the handouts from Wayne at his Spring Meeting seminar. Thanks again Wayne!

Plants:  Structure and Function

Roots: 

  • passively absorb water, when the soil is moist enough
  • actively pump water in, when soil is less moist

Leaves:

  • photosynthesis uses water, respiration produces water
  • photosynthesis should exceed respiration
  • transpiration – evaporation of water through stomata (stoma – singular)

Wilting is a NORMAL reaction of a plant to dehydration, plants compensate

Soil: Structure and Function

Soil is a complex mixture of inert particles, organic matter, and biological agents.  The inert particles are classified by size, with clay being the smallest.  Larger particles are silt, sand, and then increasing sizes of gravel. 

Clay: 

  • the particles pack tightly, holding water well but reduce the “air spaces”
  • when very dry, it contracts and forms large cracks

Sand: 

  • particles pack less tightly, holding water poorly, but allow larger “air spaces”
  • particles pack less tightly, holding water poorly, but allow larger “air spaces”
  • when it dries, there is little change in its appearance or  texture

When sand and clay are mixed they tend to separate, as the clay settles down to the lowest levels, leaving sand and gravel nearer to the surface.

Environmental factors:

Sun: 

  • exposure of plants and soil to sunlight increases the demand for water
  • shade reduces photosynthesis rates, transpiration and drying of the soil
  • reflection of light from walls or fences increases intensity and water demand

Wind:

  • increased wind causes an increase in transpiration, and soil evaporation 

Good Practices to Reduce Water Usage:

1. Choose better plants:  irises vs hydrangea; hostas  vs trilliums

2. Soil Amendments:       addition of peat moss, compost, organic matter

3.  Planting: 

  • timing: spring or fall, avoid summer, cloudy days, imminent rain
  • process – water and organic matter in the hole, transplanter fertilizer, optimum spacing, topping the leaves / stems

4.  Seeds: presoak larger seeds, trench, water, seeds, cover

5.  Deep Rooting: water retaining material below the plants, promote deep, strong roots 

6. Watering: water very early in the morning, or late in the evening, water heavily when you water, don’t “wet” the surface

7. Mulch: reduces soil temperature, evaporation, lighter coloured mulches preferred 

8. Potash: addition (August) of potassium to soils (especially sand), reduce water loss by plants

9. Windbreaks: trees, shrubs, and fences slow wind, reduced water needs

10.   Raised Beds: dry faster, line the sides with heavy plastic, mulch well