Lemon Tree

Year-round

In the Bay Area's mild, foggy coastal climate, a lemon or Meyer lemon tree does well in a sunny, wind-sheltered spot with steady but not soggy water.

• Give it the sunniest spot in the yard, ideally against a south or southwest facing wall or fence where it can soak up extra reflected warmth.
• In foggy coastal pockets, an acid citrus like lemon or Meyer lemon does better than a sweet orange, since Bay Area summers usually don't get hot enough to sweeten oranges.
• Water deeply, then let the soil dry out a bit before watering again. Overwatering is the more common problem here, and it can even cause the fruit to split.
• Feed with a high nitrogen citrus fertilizer a few times a year rather than constantly. Overfeeding invites pest problems like citrus leafminer.
• The fruit itself is edible for people, but the leaves, peel, and other plant material are toxic to dogs, cats, and horses because of essential oils and psoralens, and can cause vomiting, diarrhea, or skin irritation if a pet chews on them. Keep dropped fruit and trimmings picked up.

Fall

Fall is a slow-down season. Ease off water and fertilizer, and skip heavy pruning while pest pressure lingers.

• Growth slows as days shorten, so watering can taper off too. There's no fall feeding on the local schedule, the last round lands in June.
• Skip heavy pruning through fall. Fresh cuts and the new growth pruning triggers can attract citrus leafminer, whose larvae leave squiggly cosmetic trails in the leaves.
• Keep watching for whiteflies, thrips, mites, and scale, and hose the foliage off if you spot them building up.

Winter

Winter is frost-watch season on the coast, plus the year's first fertilizer feeding as the tree gears up for spring bloom.

• Fog and the ocean's moderating effect mean frost risk is genuinely lower right on the coast than it is a few miles inland, so exact protection needs vary a lot by microclimate.
• When a freeze is forecast to hit 30 degrees F or below, water the tree first since moist soil holds heat better, then cover the canopy.
• Wrap the trunks of young trees in burlap or newspaper, and drape a sheet or frost blanket over small trees on cold nights. Old-style incandescent string lights woven through the branches add a little extra warmth too.
• Pick any ripe fruit before a hard freeze hits, since a freeze can ruin fruit still hanging on the tree.
• The first of the year's three fertilizer feedings usually lands in January or February.

Spring

Spring is bloom, light pruning, and the first feeding of the year for a Bay Area lemon tree.

• Prune lightly right before bloom or right after the spring fruit sets. Citrus don't need heavy pruning, just shaping, better airflow, and removing suckers.
• March is generally the best pruning window in the South Bay, and Marin guidance points to the same pre-bloom to post-fruit-set stretch.
• Give the tree its first feeding of high nitrogen fertilizer around February or March, the first of three rounds Bay Area schedules call for each year.
• Expect a wave of fragrant flowers, and don't worry when a lot of the flowers and tiny fruit drop on their own. That's the tree thinning its own crop, not a problem, unless you also see yellowing leaves or branch dieback.

A light, shaping prune after bloom keeps a front-yard lemon tree looking neat and HOA-friendly instead of overgrown.

Summer

Summer is the thirstiest stretch of the year, plus the last scheduled feeding, for a Bay Area lemon tree.

• Water more often in warm weather. Established trees generally take around 4 to 6 inches of water a month in summer, applied as a few deep waterings rather than daily sips.
• Let the top 3 to 6 inches of soil dry out before watering again so roots aren't sitting in soggy ground.
• June typically wraps up the year's three rounds of fertilizer for Bay Area citrus.
• Warm weather also brings out aphids, scale, and mites. Hose the leaves down now and then, and put a sticky band around the trunk to keep ants away, since ants protect the pests that produce the honeydew they feed on.