Q: This spring I would like to plant some blueberry bushes. The soil in this area is mostly clay, with a heavy limestone content. I have dug several holes about 2 feet deep, 3 feet in diameter, and 5 feet apart. The soil from the holes has been mixed with a generous amount of decayed organic matter and replaced. I would like to add an amendment to the mixture to acidify it. However, I have been told not to use aluminum sulfate because it will stunt the blueberry plants. What additive would be best for the blueberries?
Also, I would like to have some way to test the pH of the soil. I know there are several labs in the area that can do this for a fee, but over a long period the cost becomes burdensome. I have noticed, in gardening magazines, a meter with a probe that is inserted into the soil to test the pH factor. Are these devices accurate or just a gimmick? Are there any low cost alternatives to the lab method? I would appreciate any advice that you can offer. – Jon Lutgring
A: Blueberries do best on loose, even sandy, acidic soils. It is very difficult to lower pH by a large amount and keep it low for an extended period of time. Blueberries prefer a soil pH between 4.0 and 5.1. In home garden situations, a pH somewhat higher than 5.1 can be tolerated if other cultural practices are optimum. Soils with pH higher than 5.1 can have pH corrected by applications of sulfur or aluminum sulfate. I don’t know any reason why aluminum sulfate would stunt the plants unless it is not properly mixed into the soil.
Preferably, the soil pH would be corrected one or two years before the plants are set.
It may be best to build a raised bed and bring in completely new soil, amend highly with
peat moss and test the pH. Have a professional lab run the pH for you initially, then buy one of the meters and see how your results compare to the lab. Generally, you get what you pay for in regards to pH meters. The cheap ones aren’t usually accurate but will give you a rough idea of your pH.
Q: Last year I wrote and asked about planting asparagus seed. I planted one long row at the beginning of my garden. Then the garden was flooded by heavy rain. Since nothing came up, I planted lima beans in the same row. Well, the garden was flooded by a second heavy rain, and the limas rotted.
After quite a while, weeds came up. Finally, I noticed some asparagus in the weeds. I weeded it, and now I have a nice row of asparagus. It’s been quite a conversation piece here at the farm. – Gertrude Goebel, Andrews, Ind.
A: They say a watched pot never boils- maybe your asparagus decided not to come up until you gave up on it!
Q: I have several Christmas amaryllis. They are about three or four years old. For a couple of years they bloomed beautifully, but for the last two years they have gotten leaves but do not shoot any flowers. I leave the leaves on the bulbs until spring, at which time I set them outdoors for the summer by burying the pots in soil. I bring them indoors in late September before frost, put them in the basement for about six weeks or so to rest, and then repot them to bloom at Christmas time. Can you help me? Do amaryllis only bloom for a couple of years? – Mrs. James Wilder, Monroe, Ind.
A: Make sure you fertilize regularly after the plant finishes blooming and when you bring it out of dormancy. Amaryllis do not require a chilling period like many other flowering bulbs, but they do require a period of cool, dry dormancy at 40-55 degrees Fahrenheit. Make sure your basement is cool enough. Try repotting your bulbs this year and provide cool temperatures (55-65 F) when you bring them indoors.
Q: Can you tell me what the problem was with my zucchini last year? I am enclosing pictures of blooms on 12- and 14-inch stems. My vines were huge and very healthy, but they were loaded with these long-stemmed blooms. A very few zucchini appeared, but they decayed as soon as they shed the bloom. The only thing I can come up with is that they were not pollinated. Thank you. – Lowell Caudill, Linton, Ind.
A: I ran this past a couple of vegetable experts at Purdue. They said most of the flowers are male blooms, which explains the lack of fruit. Weather or low light can be culprits for causing few female flowers. Also, nutrition, soil moisture and cold could affect the stalk length, although they have never seen any as long as yours. It seems everything about zucchini happens in abundance!
Q: For two or three years our tomato plants have been turning black from the ground up, then they die. We would appreciate some help. I heard on television that Epsom salts would take care of this, but they didn’t tell how to use it. Do you have any advice for this problem? – C. Musselman, Kendallville, Ind.
A: Tomatoes are susceptible to various problems, so you should take a sample to your county Extension office if the problem recurs this summer. At the very least, ask your Extension office for a copy of HO-26A, “Tomatoes,” and BP-3, “Five Steps to Healthy Garden Tomatoes.” Epsom salts are magnesium sulfate, so applying this product would only be helpful if either magnesium or sulfur are lacking in the soil. The blackening of your plants sounds like an infectious disease, which isn’t likely to be remedied by Epsom salts.
Q: When we dug our potatoes they had spots on them, and when you peeled them you had to peel part of the potato to get away from the spots. Is there something we could put on the ground to avoid this? – Adrian Miller, Winamac, Ind.
A: Potato scab is a disease common to some potato cultivars that are grown in alkaline soil. Plant certified, disease-free tubers of cultivars with good scab resistance. These include ‘Norchip,’ ‘Norland,’ ‘Superior,’ and ‘Oneida.’ ‘Katahdin’ and ‘Kennebec’ have fair scab resistance.
Dry soil favors scab infection, so water regularly, especially from flowering to six to nine weeks thereafter. Avoid excessive lime, manure or wood ashes. Rotate the area out of potatoes every three or four years.
Lowering the pH to a range of 5.0 to 5.5 will decrease the incidence of scab infection. Have your soil tested to determine its current pH, and apply sulfur to lower pH if necessary. Sulfur application rates are available from your county Extension office. Ask for HO-62A, “Potatoes.”