One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

It's a good idea to figure out when it's possible to plant delphinium by using the USDA zone info for Rahway.

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 slightly earlier in the year because they are barely cold tolerant.

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

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

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Rahway. It might get as low as 0°F during the coldest months of winter.

Keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Rahway and it changes from year to year. Half of the time in Rahway you get a frost after April 15 so make sure that you are ready to protect your delphinium if you have one of those late frosts.

USDA Zone Info for Rahway

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	0°F
Highest Expected Low	5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Rahway

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