Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A way of making a decision about when to plant delphinium is to check out the USDA zone info for Rosemead.

Planting Calendar for Delphinium

Frost tolerance for delphinium:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

You can plant delphinium just a tiny bit earlier in the year because they do ok in moderate cold.

The earliest that you can plant delphinium in Rosemead is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant delphinium and expect a good harvest is probably September. If you wait any later than that and your delphinium may not have a chance to grow to maturity. You can get started a little bit earlier by starting your delphinium indoors.

Last Frost Date

The average date of last frost is January 31 in Rosemead. In the coldest months of winter you can expect an average low temperature of 30°F.

It's important to remember that USDA zone info for Rosemead is an average and the actual date of last frost is different every year. Half of the time in Rosemead it frosts late in the year after January 31 so make sure that you are ready to cover your delphinium if you have one of those late frosts.

USDA Zone Info for Rosemead

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 Rosemead

You may be interested in your other planting guides for Rosemead.