American blueberry

Year-round

Highbush blueberry comes from wet, acidic ground in the eastern United States, and the Los Angeles basin is close to the opposite of that, with alkaline clay soil, dry summers, and mild winters. It can still grow here, but it needs to be treated like a plant that does not belong in native ground. That mainly means a container or raised bed, an acid soil mix, and a low chill variety bred for mild winters.

• Grow it in a large container or raised bed filled with an acidic mix, such as peat moss or coir blended with pine bark, instead of planting straight into Los Angeles clay or loam.
• Test the soil or potting mix pH and work in wettable soil sulfur if it reads above 6.0, then wait a few months before planting so the sulfur has time to work.
• Choose a southern highbush variety labeled for a low winter chill requirement, since much of the Los Angeles basin does not reliably supply enough winter cold for standard eastern highbush types.
• Feed with an acid forming fertilizer made for azaleas or camellias, starting once new spring leaves are fully open.
• Blueberry does not appear on the ASPCA's toxic or non toxic plant lists for cats or dogs, so there is no published warning either way, but the fruit itself is a normal human food crop.

Fall

Fall in the Los Angeles basin stays mild and dry, and it is one of the two good windows extension planting guides give for getting a potted blueberry into the ground or into a bigger container.

• November through December is a good time to plant potted blueberries here, since the ground is not frozen and roots have time to settle in before next summer's heat.
• Test the soil or potting mix pH now if you have not already, so there is time to work in sulfur before a late winter planting.
• Ease off watering frequency as days cool, but do not let the root zone dry out completely, since blueberry roots stay shallow.
• Enjoy the fall leaf color. Highbush blueberry is one of the few plants in a Los Angeles yard that turns real red and orange before winter.

Winter

Winter is short and mild here, but it is the season that decides whether this plant really works in the Los Angeles basin, because highbush blueberry needs a certain number of cold hours to grow and fruit well the following year.

• Choose a southern highbush variety labeled for a low chill requirement, since Los Angeles basin winters often do not supply enough cold hours for standard eastern highbush types.
• Late winter, before new growth starts, is the right time for bare root planting and for pruning out dead, weak, or crossing wood on an established plant.
• If you have not acidified your soil or potting mix yet, do it now with wettable sulfur so it has time to work before spring planting.
• Keep potted blueberries out of any hard freeze, though a normal Los Angeles winter cold snap will not hurt the plant.

A late winter prune keeps the bare, leafless shrub looking cared for near the front walk instead of scraggly until spring leaf out.

Spring

Spring in the Los Angeles basin is mild and still carries some rain, which makes it a good window to plant a new blueberry or start its first feeding of the year.

• Plant new bare root or container blueberries now if you have not already, into a raised bed or large pot with acidic mix rather than straight into unamended clay soil.
• In the plant's first year, pinch or strip off any flower buds so its energy goes into roots instead of berries.
• Once new leaves are fully open, start monthly feeding with an acid forming fertilizer made for azaleas or camellias.
• Refresh a 2 to 3 inch layer of pine bark or pine needle mulch to hold moisture and keep shallow roots cool as days warm up.

Summer

Los Angeles summers are hot and dry with almost no rain, which is the hardest stretch for a plant built for humid eastern summers, so steady watering and shade planning matter most now.

• Water deeply two to three times a week rather than a light daily sprinkle, since blueberry roots are shallow and dry out fast in our dry heat.
• Keep mulch topped up at 2 to 3 inches to hold moisture and keep roots cooler through hot inland stretches.
• If leaves turn yellow between the veins, that is often a sign the soil has drifted back toward alkaline, treat with another round of soil sulfur or a chelated iron product made for acid loving plants.
• Give inland and valley plants some afternoon shade during the hottest part of the day, while coastal plants can usually take more direct sun.
• Net ripening fruit if birds are stripping berries before you get to pick them.