Blueberries, the wonder food: a powerhouse of nutrition and antioxidants. Kids and adults alike love them fresh off the plant, on cereal, in desserts. And blueberry plants are beautiful in the garden. I often design these highly ornamental shrubs into a garden to provide edibles in the landscape that serve both as a fun food to nibble as you walk in the garden and to provide a colorful accent in the fall when the foliage turns fiery red, orange and yellow.
Under the branches of a large shade tree at UCSC Farm & Garden, I met with fellow blueberry enthusiasts for a workshop recently to learn from the experts how to grow blueberries in the home garden. Liz Milazzo, field production manager, shared her personal top 8 varieties. She also told us how to choose varieties for different locales and growing conditions, how to select an appropriate planting location, prepare the planting hole or container, create soil conditions that blueberries need to thrive, how to pruning correctly and care for your blueberry plants to keep them productive.
UCSC Farm & Garden grows 1/10th of an acre of different kinds of blueberries. As we walked between the rows of plants for the pruning demonstration I noticed many of them still had leaves and almost ripened blueberries. Liz explained that these berries were set last November and although they are ripening slowly their taste will be inferior. The best tasting berries will come from flowers set in March. You can choose early and late ripening blueberry varieties to extend your harvest. Berry size and overall yield are more important to commercial growers as are varieties that set in clusters making it easier for them to harvest. For the home gardening, taste is what we are looking for and it's easy for us to pick a berry here and another there as they ripen to perfection.
So what are the top picks of the Farm manager? Drumroll, please. Her #1 pick for the Santa Cruz area is Southmoon. This variety produces early, mid and late season and is a nice blend of acid and sweet. Coming in at #2 is Jubilee, an upright shrub with sky blue berries. Liz also likes other southern highbush varieties such as O'Neill, Santa Fe, Sapphire, Windsor, Jewel and Misty.
Some of these are tall woody plants while others are more spreading. For containers, a tall variety like Windsor or Jewel would not work as well as a medium sized bush with an arching form such as Misty, Southmoon or Jubilee.
Blueberries need 6 hours of sun or more, regular watering and lots of mulch over their roots. They naturally grow in bogs. The year before the Farm planted their blueberry field, the pH of the soil was 6. Blueberries prefer more acidic conditions so after having their soil tested they tilled in redwood mulch and soil sulfur at the recommended rate. Striving to keep the soil at 4.5 – 5.5 pH they renew the mulch yearly in the fall and add vinegar to the water each time they irrigate to acidify the soil. The Farm uses a commercial grade vinegar but the home gardening can use inexpensive white vinegar at a rate of 1 tablespoon/gallon of water. Liz explained that this will bring city water down to a pH of 5 and blueberries love it.
The Farm irrigates the blueberries 2-3 times per week with 1/2 gallon per hour emitters on a drip line every 12". They place 2-3 emitters per plant.
Because blueberries require acidic soil rich in organic matter an easy way to supply this is to buy rhododendron and camellia ready made organic soil and use it in containers or to amend native soil 50%. Renewable and sustainable soil amendments include cottonseed meal, feather meal and mustard meal which comes from crushed mustard seed. Pescadero Gold available at Mountain Feed is a good source for mustard meal.
A 3-4" layer of mulch over the roots is especially important as blueberries have shallow roots close to the surface of the soil. They don't have root hairs like other plants and depend on mycorrhizal fungi to absorb nutrients. Protect this active zone with a mulch of organic woody material such as wood chips, redwood compost, clean sawdust, pine bark, pine or redwood needles.
Blueberries deserve a little extra attention to their growing conditions. They repay you with scrumptious, nutritious berries.