Community ClicksQ: A recent test of the soil from our blueberry patch showed a pH of 3.7 and low calcium.
Our blueberries are not doing well.
Can soil be too acidic for blueberries?
A: pH is a measure of acidity.
A pH of 7 is neutral; a pH of less than 7 is acidic.
Blueberries like acidic soil with a pH between 4.5 and 5.5; a pH of 3.7 is too acidic for them.
An excessively low soil pH increases a plant’s uptake of aluminum and manganese; decreases its uptake of calcium, magnesium and potassium; and decreases soil microbial activities that contribute other nutrients to the plant.
None of these things are good for your blueberries.
Too much aluminum results in poor root development; a low calcium accentuates the root problem and causes new leaves and root tips to die.
To increase the pH by one unit to 4.7, incorporate finely ground dolomitic limestone into the soil at a rate of five pounds per 100 sq. ft. of bed.
This amount will change the soil pH slowly so that you don’t make it too alkaline.
The limestone will not only increase the pH but also provide the needed calcium.
Q: Is it okay to plant a purple raspberry next to a red raspberry?
A: Although different raspberries types will grow next to each other, it is not always advisable to plant them in the same row.
Red raspberries put out new canes from both their crowns and roots and quickly spread beyond the original plant.
If you grow purple raspberries in the same row as red raspberries, the purple raspberries will likely be overtaken by the red raspberries.
One the other hand, purple and black raspberries usually put out new canes only from their crowns and do not spread as readily as red raspberries.
They probably can be planted next to each other in a row.
Q: I just repotted my spider plant.
Is there something wrong with the roots?
A: Spider plants (Chlorophytum comosum) are easy-to-care-for houseplants that form thick, fleshy tubers on their roots.
These tubers store water and sustain the plant during drought but can quickly fill the pot.
Crowded roots encourage spider plants to produce baby plants on long stalks, but they also prevent water from soaking through to the center of the root mass and can force the plant out of the pot or crack the container.
When the roots of your spider plant become too crowded, repot the plant into a larger container.
Be sure to break up the root mass and remove some of the tubers to allow new potting soil to fill in around the roots.
Q: I understand that sweet cherry trees need pollen from a different variety to set fruit.
Can an ornamental cherry tree cross-pollinate a sweet cherry tree?A: Although there are sweet cherries that are self-fruitful and do not need a cross-pollinator, most sweet cherries need pollen from another cherry variety to bear fruit.
Ornamental cherries have double flowers or extra petals that occur at the expense of reproductive organs or structures that produce nectar.
They typically do not produce pollen, and even if they do, the bees aren’t interested in visiting them.
If you have a sweet cherry that is not self-fruitful, you need another sweet cherry that blooms at the same time to pollinate it.
Tart cherries generally bloom too late to be reliable cross-pollinators.
Some sweet cherries, however, are genetically incompatible and will not pollinate each other.
To select compatible sweet cherry varieties, check out WSU’s Fruit Handbook for Western Washington available for free at http://cru.cahe.wsu.edu/CEPublications/eb0937/eb0937.pdf.
Jeanette Stehr-Green is a WSU certified Clallam County Master Gardener.
Send your garden and plant questions to This Week’s Garden by sending an email to news@sequimthisweek.com.
Your questions may be edited to fit the available space.
If we are not able to answer your question in a column, we will contact you directly if you provide your email address or telephone number.
For more gardening information, attend the Green Thumb Gardening Tips Brown Bag Series at the Clallam County Courthouse, 223 E. Fourth St. in Port Angeles.
These free educational events are held at noon on the second and fourth Thursdays of each month.
On July 28, veteran Master Gardener Larry Lang will talk about low-maintenance gardening.
