Is it possible to grow cultivated blueberries in garden soil that have been limed and fertilized for many years?
It is both possible and easy, and inexpensive to prepare such garden soil for cultivated blueberries.
Growing Culture For Vigorous Plants
I have 160 plants of a dozen varieties, but the most interesting blueberry project is the row of 12 plants growing in soil that has been limed and fertilized for years.
If the soil is reasonably well drained, you can lower the pH reading from 6.5 to 5.5 without difficulty, as will be explained.
You indeed find vigorous, highly-productive plants in swampy areas. But if you examine closely, you will discover that the plants usually grow on hummocks.
In one of my experimental plots, the plants have made very poor growth where water lies in the spring and after heavy rains.
Choose a spot with adequate drainage for your plants. Then, with deep mulching and the sprinkler, you can provide the moisture essential for both vigorous growth and productivity.
Five Essential Points For Growing Blueberries
With blueberries, there are five essential points to consider.
Soil Acidity
First, acidify the soil a few months ahead. If you plan to set out plants next spring, acidify this fall.
In average soils, 3 pounds of powdered sulfur per 100 square feet will lower the pH by one degree.
If you have average-type loam soil, it is probably between 6 and 6.5.
The safest method is to send a soil sample to your state experiment station. First, write to the station for its direction sheet on taking and sending soil samples.
I figured on a 4’ foot wide strip, 50’ feet long. Six pounds of powdered sulfur brought the reading from pH 6.2 to about pH 5, and in that reading, the plants are doing well.
Scatter the sulfur and rake it into the top 2” or 3” inches of soil. Then allow time for soil bacteria to oxidize the sulfur, at least 3 months.
What little data I have on this point indicates a 6 months period gets the plants off to a better start.
Soil Mixture And Planting Depth
Second, dig the holes 2’ feet in diameter and 8” inches deep. Mix ⅔ of the sulfurized soil with ⅓ sawdust by volume to fill the hole.
In some of my early experiments, I used ½ sawdust and ½ soil, but the ⅔ soil mixture gives better results.
The blueberry plant, unlike most, has no strong root hairs. Instead, the mass of blueberry roots is fine and thread-like and needs a porous soil in which the roots can push their way.
When planting, a common mistake is to set plants too deeply. Instead, try to keep the mass of roots about 3” inches from the surface.
Plants are set 4’ feet apart. It takes five or six years before they bear much of a crop.
That is why it is well to set out three or four-year-old plants if one can afford it.
After the plants are set, keep them well-watered for at least a fortnight. Blueberries may be set either in the fall or in the spring.
Mulch Adequately
Third, after the first year and the weeds are well eliminated, mulch heavily. I prefer a well-packed layer of old hay, about 4” inches deep.
One can also use the following:
- Peat moss
- Sawdust
- Shredded sugar cane
If you have witchgrass in the spot where you plan blueberries, get rid of it before setting out the plants. The only certain way I know is to spade it out.
I use a long-handled five-tined fork, often called a stone fork. You cannot raise blueberries in competition with witchgrass any more than you can raise raspberries or asparagus in witchgrass-infected soil.
Fertilize With Ammonium Sulfate
Fourth, fertilize with ammonium sulfate. I use no fertilizer the first year, but I apply two ounces to each plant in the second year.
One ounce is spread in early April, with the second application made about June first.
Each year after that, I increase an ounce to the half pound level. I spread half the annual application in early spring and the other half on June first.
You can spread the fertilizer on the mulch, and the rains or the sprinkler will take it down into the soil.
Annual Spring Pruning
Fifth, after the plants are three years old, the annual spring pruning is one of the major secrets of a satisfactory annual crop.
Write to your state experiment station for a free bulletin on cultivated blueberries.
In general, I have found that most of us do not prune enough after the plants reach maturity.
Choosing Excellent Blueberry Varieties
Regarding choosing varieties, I like Jersey, Pemberton, Atlantic, and Rubel, four of the older ones.
I am trying new varieties, too, including Berkeley, Dixi, Herbert, Earliblue, and Bluecrop, but have not had sufficient experience with these to offer an opinion.
Undoubtedly some of the newer varieties will prove better than the older ones. However, the first four varieties mentioned are doing well for many growers.
44659 by Haydn S. Pearson