Here are a few cases where a soil test would help you have the greatest success:
- Colorado and Norway spruce grow best at pH 6.0 or above. If planting these types and soil pH is less than 5.8, add approximately 6 lbs (6 cups) lime within the expected mature tree drip line (minimum 3 ft by 3 ft) and incorporate to a depth of 6 to 8 inches prior to planting.
- White and red cedar grow best at pH 6.8 or higher. If planting these types, and soil pH is less than 6.6, add 9 lbs (9 cups) lime within the expected mature tree drip line (minimum 3 ft by 3 ft) and incorporate to a depth of 6 to 8 inches prior to planting.
- Black walnut and Kentucky coffee tree grow best at pH 6.8 or above. If planting these types and soil pH is less than 6.6, add approximately 9 lbs (9 cups) lime within the expected mature tree drip line (minimum 3 ft by 3 ft) and incorporate to a depth of 6 to 8 inches prior to planting.
- Blueberries require acidic soils. Michigan State University Extension recommends the soil pH be between 4.5 and 5.5. If you plant blueberries in the neutral soils (soil pH 6.5 to 7) favored by most plants, the plants will be yellow and grow poorly if they grow at all. Most people do not have soil that is naturally that acidic, and so often their blueberries fail if they do not use a soil amendment.
- Black-eyed Susans, day lilies, mums, lavendar, asparagus, tomatoes, pole beans, beets, brussel sprouts, kale, spinach, crookneck squash, and peas all love soil between 6-7.5.
- Azaleas, camellias, rhododendrons and blueberries are just four of the plants that love to sink their roots in acidic soil. Gardeners label these plants “acid-loving," but it's not really acid these plants seek. Rather, they crave the nutrients that low-pH, acidic soil provides.
- Holly plants are one of the most recognizable symbols of Christmas and they grow best in well-drained and moist soil with a pH level between 5.0 and 6.0.
- Hydrangeas are one of these plants that will keep surprising you. If you provide them with acidic soil, they will bloom blue, but if you add a bit of lime, they will change the color to a more pink one
- Adding large quantities of organic amendments to the planting hole is usually not a good practice. If soils are ‘heavy’ and have poor drainage, the extreme textural and soil structural differences between the hole and the area surrounding the hole may inhibit roots from extending beyond the altered area. It is best to plant trees and shrubs in existing soil, even if it is not ideal. Choosing a species that can adapt to these less than ideal existing conditions may be more practical.
Ask us for a soil test bag and we will help you get the testing process started!
SOURCES: UW SOIL & FORAGE LAB, https://uwlab.soils.wisc.edu/resources/tree/, BackyardSidekick.com, Pennington.com