What to plant this week in San Jose, CA
With temperatures holding steady at 25°F and frost dates safely settled for late January, San Jose gardeners are well into the deep warmth of our Mediterranean climate. This week marks a critical harvest window for heat-loving crops like zucchini, cucumbers, and melons that thrive in our long, dry growing season.
The next 7 days
San Jose, CAGrowing in San Jose right now
- Utilize your existing greenhouses or shade cloth now to protect delicate transplants from occasional late afternoon thunderstorm gusts common in the Santa Clara Valley.
- Apply a slow-release nitrogen fertilizer to heavy clay soils around squash and beans to counteract nutrient locking before the hot summer drought sets in.
- Plant Daikon radish seeds directly into raised beds this week, as our cool soil moisture is still holding after winter rains.
Sow this week
1 crops- Daikon Radish
Transplant this week
Nothing is due to go out this week.
Harvest soon
44 crops- Acorn Squash
- Basil
- Borage
- Bush Bean
- Butternut Squash
- Cantaloupe
- Celosia (Cockscomb)
- Cleome (Spider Flower)
- Cosmos
- Cowpea (Black-Eyed Pea)
- Cucumber
- Delicata Squash
- Edamame
- Fennel
- Flour Corn
- French Marigold
- Garden Verbena
- Garlic
- Gomphrena (Globe Amaranth)
- Gourd (Ornamental/Bottle)
- Honeydew Melon
- Lima Bean
- Loofah (Luffa)
- Malabar Spinach
- Morning Glory
- Nasturtium
- Okra
- Pole Bean
- Pumpkin
- Purslane
- Roselle (Cranberry Hibiscus)
- Scarlet Runner Bean
- Shiso (Japanese Basil)
- Spaghetti Squash
- Summer Savory
- Sunflower
- Sweet Corn
- Thai Basil
- Vinca (Madagascar Periwinkle)
- Watermelon
- Winter Squash
- Yellow Summer Squash
- Zinnia
- Zucchini
Seasonal tips
- Start succession planting cool-season greens now that the ground has warmed up slightly after the last frost date.
- Apply a light layer of mulch around established squash and melons to retain moisture as summer heat approaches.
- Divide and transplant perennials like borage and verbena while they are still dormant or just starting to grow.
Pest & disease watch
- Monitor for aphid clusters forming on new Basil and Zinnia growth due to recent humidity spikes from passing marine layers.
- Check the undersides of Pole Beans for spider mites before they multiply during the upcoming dry spell.
- Inspect watermelon vines for squash bugs which are becoming active as temperatures rise above 70°F.
Watering this week
Water deeply in the early morning to conserve heat and reduce evaporation during these mild days.
Harvest your acorn and butternut squash soon while the skin is still hardening to ensure long-term storage success.
San Jose gardening questions
3Can I still plant tomatoes in San Jose now, or should I wait?
Tomatoes are best started indoors right now and transplanted after the last frost date of January 30 to avoid shock. Planting them directly into cool ground can result in stunted growth until our soil warms up.
My Zucchini plants have yellow spots; is this normal for San Jose weather?
Yellow spotting often indicates downy mildew, which thrives when our fog burns off quickly leaving moisture on leaves. Spray with a copper fungicide immediately and increase air circulation by removing lower leaves.
When should I start harvesting my Watermelon crop?
Harvest your Watermelons now when the ground spot turns creamy yellow and the tendril near the stem dries out completely. Our valley heat usually ripens these fruits within 8 to 10 weeks of pollination.
Other cities in zone 9b
10See the full zone 9b guide → · Plan your San Jose garden in SproutGuide →