California Gardeners' April Checklist: Sustainable Spring Gardening

Water shortages, energy crises, and modern realities have taught Californians valuable lessons about conserving precious resources. In our gardens, we've pioneered sustainable approaches beautiful and appropriate for our Mediterranean climate.

Visit a nursery this month and you'll see plants unheard of a generation ago—from the Mediterranean, Australia, South Africa, California's wild places, and breeders' greenhouses. Plants needing less water and care: lavender, countless succulents, natives, lawn alternatives, and more.

See What Steals the Show

A recent San Francisco Flower & Garden Show featured climate-appropriate plants. One standout: Agave attenuata 'Ray of Light', with white-trimmed, light green leaves in sculptural symmetry. Young plants, about a foot across in gallon containers, are ready-made for a terra-cotta pot on a patio table.

Botanical name: Agave attenuata 'Ray of Light' (variegated foxtail agave)
USDA zones: 9–11 (find your zone)
Water requirement: Light
Light requirement: Full sun or partial shade
Mature size: 4–5 feet tall, 8 feet wide
Growing tips: For containers, use cactus/succulent soil mix. This agave eventually reaches 5 feet tall and 8 feet wide—prepare to transplant in a year or two.

Landscape With Lavender

Many reasons to grow lavender: purple flower beauty and fragrance, gray cushiony foliage, bees and butterflies attracted. One of our most dependable, low-maintenance landscape plants.

Uses: Mass as ground cover. Edge a walk (trim formally if desired). Edge a border. Mix in a border. Grow in a pot. Plant under roses.

Choose from many Lavandula species/varieties by size, habit, and use:

• Lavandula stoechas (Spanish lavender): deep purple flowers; up to 30 inches; borders, pots, cottage gardens
• Lavandula angustifolia (English lavender): 'Hidcote Blue' (2 feet, mounding); 'Blue Cushion' (compact to 18 inches, low edging)
• Lavandula intermedia 'Grosso': very fragrant; compact to 3 feet; hedges, edging
• Lavandula dentata (French lavender): long bloom; 2–4 feet; hedges, edging
• Lavandula minutolii (fernleaf lavender): small, to 2 feet; good for pots

Botanical name: Lavandula spp.
USDA zones: 5–9 (some less hardy). Not good in hot, humid climates.
Water requirement: Light
Light requirement: Full sun
Mature size: 2–3 feet tall and wide, larger
Growing tips: Ensure good drainage. Control size by shearing back (up to half) after flowering. Replace when dry and woody. Some types spread seeds invasively—eradicate young plants promptly.

Go for One From the Wild

Until recently, I only saw California fuchsia (Zauschneria californica) at 7,000 feet near Echo Summit—patches of red blazing through gray granite cracks. Now it's at neighborhood nurseries (Monrovia grows it). Tamed, losing scraggly wild look but not bright color and toughness. Dependable long-blooming summer perennial for dry sunny spots, especially slopes. Hummingbirds love it.

Botanical name: Zauschneria californica
USDA zones: 6–9
Water requirement: Light
Light requirement: Full sun
Mature size: Under 1 foot to 4 feet tall, up to 4 feet wide (variety dependent)
Growing tips: Many varieties developed; 'Ghostly Red' with silvery gray foliage notable. Ensure quick drainage. Trim back and remove dry foliage in fall.

Try This Instead of Guzzling Grass

Considering a new lawn or replacing an old one? Consider water-saving, less-disease-prone alternatives to traditional grasses. Several California native grasses now available as sod need 50% less water than conventional lawns.

• Native bentgrass (shown): looks like conventional lawn grass. Mow low, withstands family wear. Left unmowed, becomes graceful meadow. Good in shade.
• Native Mow Free: mix of fescue grasses taking shade and full sun. Mow for turf look or leave unmowed for shaggy look. Mow at least twice yearly. Works on slopes but not a good play lawn.

Check local nursery demonstrations. Ensure you like texture, color, durability. Helpful reference: The American Meadow Garden by John Greenlee.

Test Out Dry Farming for Tomatoes

The most intensely flavored tomato at a late summer farmer's market was likely dry-farmed—not just water saving, but a way to concentrate flavor. It works!

Want to experiment? Basic method: withhold water after transplanting, forcing deep roots. That makes me nervous. A conservative approach: try alongside conventionally grown tomatoes as backup.

Start this month (warmest climates) or next with Early Girl, Sungold, Sweet 100 or similar. If soil isn't moist, soak first. Dig extra-deep hole, set seedlings with stems buried to first leaves. Water deeply and regularly for weeks. Stop normal watering when fruit shows. Withhold unless plant wilts. For detailed advice, download the UC Davis guide.

Even if not fully dry-farming: tastier tomatoes come from not overwatering.

See the Houzz guide to growing tomatoes

Prep for Cinco de Mayo

Essential for Mexican and Asian dishes, cilantro is easy and quick—plant early April for guacamole by Cinco de Mayo and months after. Remember: 1) short-lived annual—easy come, easy go; 2) enemy is hot weather, causing bolting.

Start seeds or seedlings in pots or ground (vegetable garden or flower border), full sun or partial shade in hot climates. Keep soil moist. Seeds sprout in a week. Cut leaves for kitchen when plants reach 3–4 inches; even if not needed, trim weekly for new growth.

For continuous crop, sow every few weeks. When plants bolt quickly, consider season over. Replant when weather cools in fall or next spring.

More cool-weather crops and how to grow them

What Else to Do in April in Your California Garden

Almost everything's actively growing—more to plant, prune, and protect than you can handle. This month usually offers more garden enjoyment than any other.

• Plant annual flowers: Except cool coastal/mountain areas, fill pots and borders with heat lovers: marigolds, lobelia, petunias. For shade, impatiens blooms until Thanksgiving or longer.
• Plant perennial flowers: Sun-loving, unthirsty types for dry season: coreopsis, sage, penstemon.
• Plant warm-season vegetables: Wait for warmed air and soil (inland valleys ready). Set out tomatoes, peppers, eggplants. Easy from seeds/seedlings: beans, beets, carrots, chard, corn, melons, squash.
• Choose and plant roses: Peak bloom lets you pick color from container-grown plants. Watch for aphids on buds and new growth.
• Plant herbs: Try pots or bed near kitchen. Thyme, oregano easy. Full sun, quick-draining soil.
• Fertilize: Almost everything benefits from complete food. Give camellias, azaleas, rhododendrons acidic fertilizer after bloom. Start lawn on monthly feeding or follow label.
• Watch for pests: Aphids love juicy spring growth. Blast with hose water before organic controls.

What's going on in your California garden? We'd love to see a photo!