How to Make a Hot Bed with Manure

The ability to start and grow vegetables eight weeks earlier than your growing season would normally allow is possible when you use a cold frame as a hot bed. While a standard cold frame adds some heat from the sun, it is transformed into a hot bed if you utilize the decomposition of manure to generate heat. Early heat for crops means the soil temperature is optimal for germinating seeds and supporting young growth without the threat of frost.

Things You'll Need

• Shovel
• Cold frame
• Fresh manure
• Pitchfork
• Water
• Garden soil
• Soil thermometer
• Vegetable seeds

Instructions

1. Dig the soil in a full sun location 3 to 4 inches deep in an area equal in size to your cold frame’s base. Dig the soil as soon as the ground is workable. Place either a store bought or homemade cold frame directly over the loosened soil facing south ideally, or west.

2. Work your manure with a pitchfork to mix in possible straw, sawdust or other bedding material that may be present. If the manure appears dry, then add water to moisten it. Fill the cold frame 1 foot deep with manure.

3. Press the manure down with the shovel blade to pack it along the bottom. Pour garden soil over the manure to 3 to 4 inches deep. Place a soil thermometer into the garden soil so you can read the temperature without moving it. Don’t push the thermometer into the manure.

4. Shut the cold frame lid. Check the soil temperature each day, waiting for the thermometer to read 80 to 85 degrees Fahrenheit for two to three days in a row, usually after a week.

5. Plant into the upper garden soil layer any seeds you want to grow in the hot bed, such as lettuce, spinach, onions, radishes and broccoli. Maintain a moist soil around the seeds through frequent watering.

6. Prop open or take the lid off the hot bed during warm spring days to avoid overheating the seedlings. Replace the lid each night until all threat of frost has passed. Keep the lid off all summer long as the vegetables grow as normal.

Tips & Warnings

• Incorporate the manure into the soil in fall after all of your vegetables have been harvested. If you don’t want to work the manure into that area, then shovel it out and put it into your composter or spread it around the base of other plants as a fertilizer treatment.

• Hot beds can also be used to start cuttings of other plants or seedlings for transplanting into other areas of your vegetable garden.

• Don’t add fertilizer to the growing plants in the cold frame. As the roots grow longer, they will extend into the manure and be fertilized naturally.

• Watch for slugs inside your hot bed, which will be attracted to the heat of the soil. Treat by hand picking and moving farther away from the frame.

References

• Ed Hume Seeds: Growing Vegetables in a Cold Frame or Hot Bed
• “Essential Guide to Back Garden Self-Sufficiency”; Carleen Madigan; 2009