When to Plant in Riverside, CA

Riverside, California, has its median last spring frost date on January 26 and its median first fall frost date on December 23, allowing for approximately 331 frost-free days each year. This extended growing season provides ample opportunity for gardeners to cultivate a variety of plants, ensuring both early spring and late fall harvests. Gardeners can take advantage of this window to explore an array of fruits, vegetables, and ornamental plants that thrive in Riverside's unique conditions.

The microclimate in Riverside is classified as Mediterranean (mild, dry summers), which creates an ideal environment for many heat-loving crops. For instance, tomatoes, peppers, and eggplants flourish in this climate, as they appreciate the long, warm growing season and minimal rainfall during summer. However, crops like lettuce and peas may struggle due to the heat, as they prefer cooler temperatures and can bolt or become bitter when exposed to the prolonged warmth typical of Riverside summers.

What to plant now in Riverside

In early spring (February to early March), plant cool-season vegetables such as lettuce and carrots, ensuring they are in the ground before January 26 to thrive in the cooler weather.
During late spring (mid-March to May), it's ideal to sow warm-season crops like tomatoes and basil, planting them after the last frost date of January 26 for optimal growth.
In early summer (June to July), continue planting heat-tolerant veggies like peppers and cucumbers. Their growth can flourish in the established warm temperatures of Riverside's Mediterranean climate.
As fall approaches (September to early October), consider planting winter crops like kale and garlic, ensuring they are established before the first frost date of December 23 to enjoy a productive harvest.

In Riverside (331 frost-free days, a very long season), 30 of 56 planner crops fit outright, 25 get two plantings, 1 crop is perennial.

Month by month in Riverside

Month	What to do
January	As winter sets in, focus on preparing your garden beds and planning your spring planting. Ensure soil is ready for upcoming crops by checking pH levels and enriching it with compost.
February	With the last frost date of January 26 having passed, begin sowing cool-season seeds like peas and radishes, which thrive in the chilly early spring weather.
March	As temperatures rise, continue planting cool-weather crops until mid-March. Start preparing for warm-season planting after the last frost by laying black plastic for warming soil.
April	By April, you can fully transition to warm-season plants. Transplant tomatoes, peppers, and eggplants started indoors, as they thrive in these warmer temperatures.
May	In May, ensure your warm-season crops are well-watered as they grow rapidly. Start your summer garden by planting beans and cucumbers for a thriving harvest.
June	June marks the height of summer. Monitor moisture levels closely and consider mulching to retain soil moisture as temperatures rise, favoring heat-tolerant plants.
July	During the peak of summer, focus on watering established crops. You may also start planting fall crops like broccoli toward the end of the month to prepare for the changing season.
August	As summer begins to wind down, continue to harvest crops like tomatoes while planting late summer crops like squash and carrots that can mature before fall.
September	In September, start transitioning your garden for the fall. Begin planting winter vegetable varieties such as kale and spinach, preparing for cooler weather.
October	October is a great time to harvest your remaining summer crops. Plant garlic now for a late fall or early spring harvest, ensuring soil is prepped for winter.
November	As temperatures continue to drop, protect your winter crops with row covers. Focus on maintaining your garden beds and prepping them for winter by adding organic matter.
December	By December 23, prepare your garden for winter dormancy. Cover sensitive crops and ensure you’ve mulched enough to protect the soil and retain moisture through the cold months.

Frost dates for Riverside ZIP codes

ZIP	Last spring frost (50%)	First fall frost (50%)	Zone
92503	January 26	December 23	10a

FAQ

When is the last frost in Riverside?

The last frost in Riverside typically occurs on January 26, allowing for a gardening season that begins in late winter.

What vegetables grow best in Riverside?

Tomatoes, peppers, and eggplants thrive best in Riverside's Mediterranean climate due to the warmth and sunshine available throughout the growing season.

When should I plant tomatoes in Riverside?

In Riverside, the best time to plant tomatoes is after the last frost date of January 26, ideally from mid-March to May.

Can I garden year-round in Riverside?

Yes, gardeners can maintain a year-round garden in Riverside thanks to its long frost-free period, allowing for diverse planting throughout the seasons.

How does Plan My Garden help Riverside gardeners?

Plan My Garden provides tailored advice, local frost dates, and planting strategies to maximize your gardening success in Riverside's unique climate.