Correcting Soil Problems - Acidic Soil

By learned about the different types of soil in your region, you can determine the best solution to put your garden at the ideal level for getting the best yield or color.

Acid Soil

Solution 1  - Test the pH with a meter or kit

Reminder that Neutral soil has a pH of 7 but most garden ideal pH is 6.8 to 6.5.  If you are below a pH of 6 then you are going to have problems

1. Take soil sample from several different spots in your yard.  Scrape off the top layer of grass and roots and take a 6" deep slice with a plastic or stainless steel trowel.
2. Place the soil in a stainless-steel or plastic bowl and let it dry.  Mix and crumble it with your hands making sure not to touch it with a tin or aluminum tool.
3. Read the directions that came with your soil kit. Add the recommended soil to the test vial.  Remember only to sure a plastic or stainless-steel tool.
4. Following the kit's direction, add the reagent or tables and distilled water to the vital and shake it for the recommended time.  Determine the pH by matching to the color against the kit's chart.

Solution 2 - Look for indicator plants

Look for acid indicators plants, some can actual come into your garden as weeds or grow wild on your land so make sure to test the pH first.

 

ACID INDICATOR PLANTS:

GRASSES	WEEDS & WILDFLOWERS
Common Bent grass (GrassesAgrostis spp.)	Wood Anemone (Anemone nemorosa)
Sheep's Fescue (Festuca ovina)	Angelica archangelica
	Blue bellflower (Campanula rotundifolia)
SCHRUBS	Meadowsweet (Filipendula ulmaria)
Hawthorn (Crataegus spp.)	Wild strawberry (Fragaria Vesca)
Holly (Ilex spp.)	Wood sorrel (Oxalis spp.)
Rhododendron spp.	Plantain (Plantago spp.)
Brambles (Ribes spp.)	Lesser Celandine (Ranunculus ficaria)
Elderberry (Sambucus spp.)	Curly Dock (Rumex crispus)
Blueberry (Vaccinium spp.)	Red Campion (Silene dioica)
High Bush Cranberry (Viburnum trilobum)	Chickweed (Stellaria media)
	Dandelion (Taraxacum officinale)

 

Azaleas thrives in acid soil

Solution 3 Add Lime 

Ground limestone is generally used to help reduce soil acidity by containing so many nutrient elements that carry a positive charge.  "Soil becomes acid when too many of the negatively charged ions on clay particles and organic matter hold hydrogen rather than one of the other positively charged cations-forms of calcium, potassium, magnesium, and some type of nitrogen." Limestone will change the balance because it is full of calcium and depending the type of limestone you have, magnesium.  When these elements enter the soil, they disperse hydrogen.  

By adding lime you may think you have fixed your problem, but this isn't a one-time fix-all solution.  Depending on the decomposed organic matter in your soil, the less quickly the lime will filter through your soil and disappear over a period of time.

Living in an area that receives a lot of rain, your solid can revert back to being too acid for your garden plants. To help against this happening test your pH every other year once you levels are 6.5.

Remember to choose the type of lime that you are going to use carefully.  Check your soil test for the levels of magnesium, it's possible to have excessive magnesium levels and still have acid conditions in your soil.

• If magnesium is high use calcitic limestone

. 

• If magnesium is low use dolomitic limestone.

 Never use gypsum to correct soil acidity.  Gypsum contains a type of calcium that doesn't alter pH so it will correct calcium deficiency in soils with optimum pH levels.

Apply limestone on a calm day because the particles are small and can drift easily.  Also wait two weeks after applying lime to apply compost or manure because lime causes nitrogen in those materials to volatilize and blow away.          

1. Measure the garden size to determine the amount of lime to use.  
2. Calculate by using the table for soil type and amount each 100 square feet.
3. Weigh the lime and sprinkle over area (if adding more than 5 pds (2.25kg) divide both the area and lime into manageable amounts
4. Rake the lime into the soil immediately to keep it from blowing away.  By setting a tiller to the shallowest depth and move slowly to mix it.
5. Water immediately. This helps it begin reacting with the soil and to let the calcium seep into the root zone.  
6. Wait about 2 weeks to begin planting

Determine the amount of lime to use by following the instructions below.

Application Rates:
Type of Lime	Soil Type	Pounds                                          (per 100 sq ft/9.3 sq m)
Calcitic	Clay soil	9
	Loam	6.5
	Sandy soil	2.5
Dolomitic	Clay soil	7.75
	Loam	6
	Sandy soil	2

 

A sandy soil of a pH of 5.8 will require less lime then a clay one with the same pH to bring it up to 6.5.  The table are standard amount to bring up the pH one point from 5.5 to 6.5 (for example).  If your soil is more acid it would be better to add the suggested amount in the early spring and then add additional limestone in the fall or following spring.

Solution 4 Choose Plant Tolerant of Acid Conditions

Plant for Acid Soils

Annuals & Perennials	Shrubs	Trees
Bugle (Ajuga spp.)	Serviceberry (Amelanchier spp.)	Fir (Abies spp.)
Butterfly weed (sclepias tuberosa)	Barberry, Red bearberry (Arctostaphylos uva-ursi)	Pecan (Caryl illinoiensis)
Chrysanthemum & Dendranthema spp.	Heather (Calluna vulgaris cvs.)	Cedar (Cedrus spp.)
Lily of the Valley (Convallaria majalis)	Health (Erica spp.)	Dogwood (Cornus spp.)
Daylily (Hemerocallis cvs.)	Euonymus spp.	Crab Apple (Malus spp.)
Iris spp.	Creeping wintergreen (Gaultheria Procumbens)	Sourwood (Oxydendrum arboreum)
Gayfeather (Liatris spp.)	Mountain Laurel (Gaultheria procumbens)	Pine (pinus spp.)
Lily (Lilium spp.)	Bayberry (Myrica spp.)	Oak (Quercus spp.)
Cardinal Flower (Lobelia cardinalis	Rhododendons & Azaleas (Rhododendron spp.)
Lupin (Lupinus spp.)	Rugosa Rose (Rosa Rugosa)
Flowering tobacco (Nicotiana spp.)
Balloon flower (Platycodon grandiflorus)
Primrose (Primula spp.)
Black-eyed Susan (Rudbeckia hirta)
Stonecrop (desum spp.)
Marigold (Tagetes cvs.)
Foamflower (Tiarella spp.)
Pansy (Viola x wittrockiana)

 

Rhododendron (rhododendron)