1. Composting Basics

2. What is Compost?
Composting is the process of breaking down organic matter, and the elements and nutrients retained in it, back to a chemical state where it is again available for plants to use

3. What Does Compost do for Soil?
Increase water and nutrient holding capacity
Balance pH (buffering)
Food for soil organisms and slow release nutrients for plants
Improves soil structure

4. Nutritious soil for healthy plants

5. Essential Components of a Composting System
Organic matter- C:N 30:1
(Plant and animal matter and manure)
Water %
Oxygen (large pore space allows for more gas exchange)
*You are creating an environment for the decomposers to work their magic

6. Carbon:Nitrogen ratio C:N Greens: Mostly nitrogen
Carbon:Nitrogen ratio C:N Greens: Mostly nitrogen. Fresh, moist, likely to get smelly Browns: Mostly carbon. Old, dry, no noticeable smell
Greens C:N ratio
Browns C:N ratio
Horse manure
18:1
Dry garden waste
40:1
Cow manure
16:1
Leaves
60:1
Chicken manure
12:1
Straw
75:1
Grass clippings
20:1
Hay
Kitchen waste
25:1
Wood chips
400:1
Fresh garden waste
30:1
Paper
150:1
Coffee grounds
Urine
1:1

7. Water and Oxygen Water Necessary for life
40-60% usually ideal in compost
As wet as a wrung out sponge
Coarser textured compost can hold more water
Too wet will reduce oxygen levels
Oxygen
Aerobic decomposition is ideal
Faster, higher quality product
Less off gassing of nitrogen
Better smell

8. Ways to Compost
Hot
Passive

9. Passive Composting: A slow, cool decomposition process mainly mediated by fungi and secondary decomposers such as springtails, sow bugs, earthworms and nematodes
Easy
Takes time
Does not kill weed
seeds and pathogens

10. Passive Compost Rings

11. Passive Compost: Rings

12. Passive Compost: Rings and Bins
Photos courtesy of Dr. Mack Thetford. Homeowner compost rings and compost bins at Press Street Gardens

13. Passive Compost: Turning Bins

14. Red Worm Composting
Redworms in bins, are fed compost and garden scraps (vermiculture)
Worms digest the compost and excrete soil (worm castings)

15. Vermiculture: Red Worm Composting
Redworms are surface feeders that consume and break down a wide range of kitchen waste and greens
Avoid feeding: meat, citrus, dairy, oils
Feed top of pile
Cover with damp and fluffed newspaper or other bedding materials
Keep moist and cool (below 84°F is ideal)
Allow for drainage
Screen or barrier to avoid mass exodus
Infamous denitrifiers (nitrous oxide evolution)
Do not expect “castings” to be a fertilizer
Great addition to potting soil, or garden soil amendment

16. Hot Composting: Higher energy input Short time,as fast as 18 days
Fast, high temperature decomposition process mainly mediated by bacteria, actinobacteria, and fungi
Higher energy input
Short time,as fast as 18 days
for initial breakdown
Kills weed seeds and pathogens
More nitrogen conserved

17. Hot Composting

18. ECUA: Bloom Yard waste and biosolids Composted at high temperatures
High quality standard
Inexpensive
Environmentally friendly
Safe

19. What to do with compost? Top dressing of compost
Top dress around perennials, trees and shrubs
Incorporate into soil before planting
Can you use too much?
Compaction, drainage issues
Nutrients will leach into soil and be incorporated by soil organisms over time
Top dressing of compost
Incorporation of compost into soil

20. Plants respond to compost!

21. Camellias like compost too
Camellias thrive is slightly acidic and well drained soil
Top dress plants with compost avoiding mounding compost close to the trunk
Slow release plant food
Cools soil
Helps manage moisture

22. Questions?