One of the first steps you take when you are making a decision about your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Diamond Bar should be looked at to determine when you can plant sweet williams.

Planting Calendar for Sweet Williams

Frost tolerance for sweet williams:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Since sweet williams do well in moderate cold you can plant them a bit earlier in the year than more sensitive plants.

The earliest that you can plant sweet williams in Diamond Bar is January. However, you really should wait until February if you don't want to take any chances.

The last month that you can plant sweet williams and expect a good harvest is probably October. Any later than that and your sweet williams may not have a chance to really do well. You can get started a few weeks earlier by starting your sweet williams indoors.

Last Frost Date

The average date of last frost is January 31 in Diamond Bar. It might get as low as 30°F during the coldest months of winter.

Keep in mind that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Diamond Bar and it can change quite a bit from year to year. Half of the time in Diamond Bar you get a frost after January 31 so be sure to be ready to protect your sweet williams if you have a late frost.

USDA Zone Info for Diamond Bar

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in Diamond Bar

You may be interested in your other planting guides for Diamond Bar.