Soil Mix

General Tips

Start your roses off right by paying particular care to your soil mix. Use a well-drained, sterilized soil that is high in organic matter. Note: When storing your soil mix, keep it on a concrete pad or other form of barrier to prevent disease and pest contamination.

The ideal soil mix has 30% pore space to allow for oxygen, water percolation and nutrient absorption. A soil mix that is too heavy can cause poor drainage and shipping problems.

Roses prefer a slightly acidic growing medium—or a pH of 5.8 to 6.5. Use limestone or dolomite to correct the pH levels.

Sample the container pH levels and electrical conductivity (salt content levels) weekly during the growing season. The water leachate should be below 3 deci-Siemens/meter during the growing season and below 2 deci-Siemens/meter at the time of shipment. To obtain water leachate sample, do the following: one hour after regular irrigation, pour distilled water into the container and capture the runoff as it leaves the bottom of the container.

Soil Mix Recommendations

Your climate and location conditions will determine your choice of soil mix. Below are some suggested soil mixes:

  • Heavy Mix: 2 parts sterilized soil, 1 part peat moss, 1 part sand.
  • Medium Mix: 1 part well-aged composted bark, 1 part sand and limestone as needed to adjust the pH level.
  • Light Mix: 1 part well-aged composted bark, 1 part peat moss, and sand if needed for additional weight.

NOTE: Sand is helpful to keep plants upright at garden centers. When using sand, mix it into the media instead of layering it at the bottom.