Blueberries top the U.S. Department of Agriculture's list of fruits high in antioxidants, and grow rampantly on the East Coast, but many Western gardeners struggle to grow even a handful.
That can change with some careful tending, say some local expert gardeners. Although blueberries are generally believed to require more rain and colder winters than seen in the Bay Area, they come in varieties that actually can thrive here with some special attention.
If you start now, you could have blueberries by July or August, just in time for a summer pie or tart.
The trickiest part, according to the experts, is keeping the soil moist and making sure the berry plants get enough sun.
One success story is Palo Alto gardener Dexter Girton, who has eight blueberry plants in his yard, in six varieties, some with berries so heavy that some branches are pulled to the ground.
"One of them is the pink lemonade variety, which means the berries are pink in color when ripe," said Girton. "The other varieties are: Bluecrop, Jewel, Misty, Harpblue, and Southmoon."
To block birds and squirrels from eating his berries, Girton said he will cover all of them with wide tulle fabric, and then bird netting on top of the tulle.
"In addition to eating fresh blueberries and freezing the ones we can't eat, we make jam with some of the blue ones. We make enough jars to give some away as gifts," Girton said.
For this kind of success, blueberries need the soil to be well aerated, moist, and very acidic, so native clay soils in the Bay Area must be well-amended to achieve this, said Master Gardener Candace Simpson, who will actually be teaching an upcoming class on this topic.
"To start out, the best way is to buy young blueberry bushes in gallon pots from a nursery, and spring is the time that most nurseries are well stocked with them," she said.
Blueberries have a fibrous, shallow root system that should never dry out, Simpson cautioned.
"The species best suited for the Bay Area are southern highbush," she said. "But northern highbush also grow very well here, even though they require more cold weather in the winter for maximum production."
"Water should be applied over the whole root zone," said Simpson. "A good way to do this is with drip tubing or small-diameter soaker hose laid in a spiral around the bush."
"In the summer in Palo Alto, we water blueberries growing in full sun and set up this way with drip irrigation three times a week for 45 minutes each time. Blueberry plants should always be well mulched to help prevent the evaporation of irrigation water from the soil surface," Simpson said.
Blueberry plants should be fertilized twice a year, in early spring and after harvest is complete, she said, and added that blueberry plants require regular annual pruning.
A common misunderstanding about blueberries is the kind of sun exposure they should get, Simpson said. "Blueberries are not shade plants. To be fully productive, blueberries need full sun. A little sun protection in the late afternoon is okay, but basically, the bushes need to be in full sun," she said.
The same rules apply to potted blueberry plants, she said.
Lise Varner grows her blueberries in containers. The Palo Alto resident and expert gardener has six blueberry plants with three southern highbush varieties, namely Sharpblue, Sunshine Blue, and Ozark Blue.
These three varieties of blueberries bring Varner a longer harvest season. Sharpblue can start in May and last through June, sunshine blue is usually in June, and Ozark Blue is later, Varner said.
"The production isn't enough to replace buying blueberries, but enough for a several handfuls two to three times per week," said Varner. "For me the main motivation is the superior taste of what I can grow at home."
These potted blueberry plants receive two to five tablespoons of a commercial fertilizer for acid-loving plants every spring, Varner said. She recommends the fertilizer usually used for azalea, camellia, and rhododendron.
Varner has containers with water reservoirs, which are called "self-watering containers," so she has a drip system that waters her blueberry plants once a week to fill the reservoirs during the summers, she said.
"If I were using regular containers, I would set the drip system to water every day or every other day to keep the soil from drying out," she added.
For inexperienced gardeners, Varner said containers could be a good way to get started with blueberries, especially if the garden has heavy clay soil that hasn't been amended yet.
"I use a commercial potting mix for acid-loving plants," said Varner. "A possible downside of containers is that they do need to be kept moist, either by regular hand watering or setting up a drip system and regularly checking that the drip system is working. "
Simpson also said it's a challenge to keep blueberries watered sufficiently in containers.
"Blueberries can do well in containers, provided their needs are met," said Simpson. "A half-barrel size container is recommended for full size varieties, but there are a few varieties that are naturally smaller."
Simpson will talk more about how to maximize a gardener's success with blueberries at Rinconada Library on May 19 at 7 p.m. The seminar belongs to a series resulting from a partnership between the library and the Master Gardeners program.
For more information on the class go to mastergardeners.org.