Carrots

Carrots are a classic cool-season root vegetable loved for their sweet, crisp flavor and versatility in the kitchen. In Santa Clara County, they grow best during the cooler months of fall, winter, and spring. With loose, well-prepared soil and steady moisture, carrots thrive here and reward gardeners with vibrant harvests in a rainbow of colors—from classic orange to purple, red, yellow, and white.

Fall crop: August–October (ideal for sweet, tender roots in cool weather)
Winter crop: November–January (slower growth, but excellent flavor)
Spring crop: February–April (harvest before summer heat sets in)
Avoid planting in midsummer—hot soil reduces germination and causes poor root development.

Full sun is best, though light afternoon shade can help in late spring.
Raised beds and deep containers are excellent, as long as soil is loose and at least 12″ deep.
Avoid compacted or rocky soil, which causes forked or misshapen roots.

Seeds: Sow ¼ inch deep, ½ inch apart in rows 12–18 inches apart.
Carrot seeds are slow to germinate (10–21 days). Keep soil consistently moist during this period.
Thin seedlings carefully to 2 inches apart once tops are a few inches tall—crowded roots stay small.
Soil prep: Work compost deeply into the bed before planting, but avoid fresh manure, which can cause forked roots.

Watering: Keep soil evenly moist, especially during germination and root development. Uneven watering can cause roots to crack.
Fertilizing: Carrots prefer a balanced soil with modest nutrients. Too much nitrogen encourages leafy tops instead of roots.
Mulching: Apply mulch to retain moisture and regulate soil temperature.
Pests & diseases: In Santa Clara County, aphids and leafhoppers can attack carrot tops. Root knot nematodes may be an issue in some soils—rotate crops regularly to prevent buildup.

Harvest typically 60–80 days after sowing, depending on variety.
Pull carrots once roots are the desired size—smaller roots are usually sweeter and more tender.
Loosen soil with a fork before pulling to avoid breaking roots.
Successive sowing every 2–3 weeks ensures a continuous harvest.

Carrots are biennial: they grow roots the first year and flower the second.
In Santa Clara County, carrots may overwinter and bolt in spring if left in the ground.
Allow a few plants to flower if you’d like to collect seed for future planting.

Carrot flowers attract pollinators and beneficial insects, especially parasitic wasps and hoverflies.
Companions: onions, leeks, and lettuce help repel pests and make efficient use of space.
Avoid planting near dill or fennel, which compete strongly and may cause cross-flavor issues.

Keep soil consistently moist during the hot, dry fall germination window by covering rows with burlap or boards until seedlings sprout.
For the sweetest carrots, grow in fall and winter—cool nights enhance flavor.
Shorter varieties (like ‘Thumbelina’ or ‘Paris Market’) do especially well in heavy clay soils common in parts of Santa Clara County.
Mix in sand or grow in raised beds if you want long, straight roots.