Castle Hill's Hardiness Zone

Our records indicate the United States Department of Agriculture has given Castle Hill a 2023 growing zone designation of 9b. Sometimes also called the planting zone or hardiness zone, this zone number gives you an idea of what plants can and cannot grow in Castle Hill's climate. If you are looking for plants suitable for growing in the Castle Hill area, head on over to our page on plants that grow well in Castle Hill, CA.

8pc Heavy Stainless Steel Garden Tool Set

Complete garden tool set with heavy-duty stainless steel tools for all your gardening needs.

Hydroponic Indoor Garden Grow Kit

Grow fresh herbs and vegetables year-round with this indoor hydroponic garden system.

Reusable Grow Bags for Tomatoes, Vegetable and Fruits

Breathable fabric grow bags that promote healthy root growth for your vegetables and fruits.

Seed Starting Trays

Perfect for starting seeds indoors before transplanting to your garden.

Understanding your growing zone is very important because it is a measure of the lowest temperature that a plant can survive, helping you to decide what plants would grow best in your particular climate. Since Castle Hill is in growing zone 9b this means that plants there can survive temperatures as low as 10 to 15 degrees Fahrenheit. Plants chosen for Castle Hill's climate should be chosen with this in mind or plants should be moved inside to keep their core temperature in the right range if necessary.