A guide to growing berries in Marin
How about some blueberry muffins, raspberry scones or strawberry shortcakes? They can be yours with some work in your garden. There’s nothing like an edible harvest. Not only are berries good for humans, but their blossoms provide pollen and nectar for beneficial insects and food for birds and wildlife.
With blueberries (Vaccinium spp.), the first step is to acidify the soil since blueberries need 4.5 to 5.5 pH and well-draining soil. It can be done by adding peat moss or elemental sulfur. It may take six months to a year for the soil to be acidified to the needed pH level. Raspberries and blackberries have the same soil requirement. Blueberries sport pink or white flowers in the spring, berries in the summer and red and yellow foliage in the fall.
Plant them anytime from fall to spring. Choose either bare root or two- to four-year-old bushes. Dig the hole 1 foot deep by 2 feet wide, spreading the roots shallowly in all directions. The shallow root system needs consistent water along with good drainage and mulch.
Although blueberries are self-pollinating, it’s better to have two or more varieties that bloom at the same time. In Marin, choose blueberries that have low chill hours between 32 and 45 degrees over the winter. The southern high bush excels with these varieties: Bountiful Blue, Sunshine Blue, Misty and Jubilee. The primary pollinators are bumblebees, which vibrate the flowers, a behavior called buzz pollination. Native bees and honeybees also pollinate. Harvest when the berry is completely blue for the sweetest flavor.
Strawberries (Fragaria spp.) are low-growing plants with red heart-shaped berries. There are two types of plants: day neutral/everbearing and short day. Day neutral produces berries from April through October, while short day delivers one crop of a better quality in late spring. Day neutral may be planted in fall or early spring for spring through fall production. If short day berries are planted in August, there will be a fall and spring-to-summer crop.
Strawberries favor sandy loam soil and regular water. In a sunny location, set out plants 12 inches apart in beds or plant them in containers or planter boxes that are 12 inches deep. Soil should be between 5.0 and 7.0 pH and can be amended with compost and leaf mold weeks before planting. Plant 4 to 6 inches deep, fan out the roots and add a 5-10-10 fertilizer. Plants will thrive with a light application of fish emulsion every four weeks. Mulch and replace plants after two or three years.
The best varieties for Marin are Seascape, Albion and Tri-Star for day neutral/everbearing and Aromas, Chandler and Sequoia for short day.
Raspberries (Rubus spp.) have perennial roots and biennial canes that fruit in the second year and become productive in the third year. Like blueberries, they need acidic soil, water and mulch.
Plant with 1 inch of soil over the crown and cut back to about 2 inches so new canes will form roots. Plant raspberries 2 to 3 feet apart along a trellis or fence for support. During the year, raspberries need nitrogen, which can be from organic sources such as blood meal, fish meal or compost.
There are two types of raspberries: fall-bearing, which may produce berries in the fall and spring, and summer-bearing, which produces berries only in the summer. When grown in full sun, raspberries are adapted to cool coastal climates. Most ripen in 40 to 60 days from bloom.
A small, thornless variety, Raspberry Shortcake, 2.5 to 3 feet, may be grown in a container. For all varieties, cut back spent canes to the ground after harvesting.
In Marin, fall cultivars that tolerate summer heat are Autumn Bliss, Bababerry and Oregon 1030. Summer-bearing ones are Chilliwack, Nootka and Sumner.
Some other delicious berries to consider are blackberries, boysenberries, tayberries or olallieberries. Happy harvesting! For more details on growing berries, go to cagardenweb.ucanr.edu/Berries.
Sponsored by UC Cooperative Extension, the University of California Marin Master Gardeners provides science- and research-based information for Marin home gardeners. Email questions to helpdesk@marinmg.org. Attach photos for inquiries about plant pests or diseases. Please call 415-473-4910 to see when a master gardener will be at the office or drop off samples 24/7 in the sample box outside the office. To attend a gardening workshop or subscribe to Leaflet, a free quarterly e-newsletter, go to marinmg.ucanr.edu.