Planting calendar
August Planting Guide for San Jose, CA: Raised Beds, Containers & In-Ground Gardens
In August, San Jose gardeners can focus on planting cool-season crops and preparing for fall harvests. This is an ideal time to sow leafy greens, root vegetables, and start some herbs indoors. Raised beds, containers, and in-ground gardens all benefit from consistent watering and soil preparation during this warm month.
Plant now (quick list)
Lettuce, Spinach, Kale, Carrots, Radishes, Beets, Broccoli, Cauliflower
Plant now
- Lettuce
- Spinach
- Kale
- Carrots
- Radishes
- Beets
- Broccoli
- Cauliflower
- Swiss chard
Start indoors
- Cabbage
- Brussels sprouts
- Herbs (cilantro, parsley)
- Leeks
- Onions
- Celery
- Tomato seedlings for fall
- Peppers for fall
Avoid
- Warm-season crops like tomatoes and peppers in-ground (due to heat stress)
- Beans (late plantings may not mature before cooler weather)
- Corn (too late for a good harvest)
- Squash (susceptible to powdery mildew in late summer)
- Potatoes (best planted earlier in the season)
Next 2 weeks
- Prepare soil with compost for fall crops
- Mulch raised beds and containers to retain moisture
- Thin seedlings for better air circulation
- Monitor for pests like aphids and caterpillars
- Water early in the day to reduce evaporation
- Start hardening off indoor seedlings before transplanting
- Check soil pH and adjust if necessary
FAQs
Can I plant tomatoes in August in San Jose?
It's generally too late to plant tomatoes outdoors in August due to heat and the approaching cooler season. However, starting seedlings indoors for a fall crop can work.
How often should I water raised beds and containers in August?
Water daily or every other day depending on heat and soil moisture, as containers dry out faster. Early morning watering is best.
What are good cool-season crops to plant now?
Leafy greens like lettuce, spinach, kale, and root vegetables such as carrots and radishes thrive when planted in August for fall harvest.
Should I fertilize my garden in August?
Yes, applying balanced fertilizer or compost helps support fall crops, especially in raised beds and containers where nutrients deplete faster.
How can I protect my plants from late summer pests?
Regularly inspect plants for aphids, caterpillars, and other pests. Use insecticidal soap or handpick pests to minimize damage.
Next steps
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