Lucious fresh blueberries in California? Yes, you can!
While blueberries traditionally grow in colder climates, there are varieties that grow successfully in warmer temperatures.
There are three main types of blueberry plant: southern highbush, northern highbush, and rabbit eye. Southern highbush and rabbiteye varieties often perform well in higher temperatures. Generally, the northern highbush types need more chilling hours than my garden can provide. Even when they do grow, the fruit often lacks good flavor. Also, the northern highbush types will take longer to start producing fruit in warmer areas. Two popular southern highbush varieties for warm areas are Southmoon and O’Neal. Santa Clara County Master Gardener offer this list of blueberry plants that perform well in warmer climates.
Prepare for planting
Blueberry plants are nearly always sold as 1-gallon yearlings.These young plants will benefit from 7 to 10 days of acclimation, or hardening off, after growing in a greenhouse. Be sure to keep the soil moist but not soggy. The root system is a hairy ball that should never be allowed to dry out completely. If it does, the plant dies. At the same time, too much water can set the stage for fungal disease. Yeah, I know - picky, picky, picky! Of course, once you start picking scrumptious blueberries off your very own edible hedge, you’ll realize it’s well worth the effort.
How to grow blueberries
So, choose the best varieties for your microclimate and taste. Even though most blueberry plants are self-pollinating, you will get a substantial increase in both fruit quantity and quality through cross-pollination with multiple plants. Plants should be spaced 4 to 6 feet apart. Blueberries perform best with 6 to 8 hours of sunlight each day, so select the site accordingly. Good drainage is important, too, so be sure to amend the planting area with plenty of aged compost. This is critical in area with compacted clay soil. Plants should be placed with the crown at soil level. Since blueberries have a shallow root system, you can help them stay happy and healthy by mulching and watering regularly in summer. Blueberries can also be grown in containers.
Blueberries seem to prefer ammoniacal nitrogen based fertilizers over nitrate based. I have heard tell that blueberries do not take up the nitrogen in nitrate based fertilizers. Too much nitrogen can burn blueberry plants, so do not feed until leaves have emerged, and then feed sparingly.
Acidifying blueberry soil
Blueberries prefer a soil pH of 4.5 to 5.5, while most San Jose, California soils are 7 or higher. This means that you may want to acidify your soil. To really know what you are working with, have your soil tested by a reputable lab. Over-the-counter test kits and strips are unreliable. Unless you want to spend hundreds of dollars on lab equipment, lab tests are really the only way to go. If it ends up that acidification is needed, try amending the soil with coffee grounds, citrus rinds, or oak leaves. You can also buy commercially available acidifiers. Keep in mind that changing pH is a slow process and that it requires regular monitoring.
Blueberry pests and diseases
Citrus thrips, katydids, light brown apple moth, masked chafer, blueberry bud mites, cranberry weevils, scale insects, Pacific flathead borers, plum curculio, sharp nosed leafhoppers, spotted wing drosophila, span worms, and Asian longhorn beetles will all try attacking your blueberry plants, but birds will probably cause the most damage. Personally, I built cage frames around my blueberry bushes and stapled netting to the frame. It works very nicely. Common blueberry diseases include twig blight, canker, stem blight, mummy berry, anthracnose, and blueberry stunt disease. Removing dead or diseased canes and treating with dormant oil can go a long way toward protecting your blueberry plants.
Your blueberry plants can live for 20 years, producing fruit after the third year.
You can grow a surprising amount of food in your own yard. Ask me how!