One of the best tools that you have as gardeners to help us estimate 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.

One way of making a decision about when you can plant helianthemum is to use the USDA zone info for Trinity.

Planting Calendar for Helianthemum

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

Helianthemum can survive in moderate cold which means that you can plant them a little bit earlier in the year than other frost tender plants.

The earliest that you can plant helianthemum in Trinity 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 helianthemum and expect a good harvest is probably September. You probably don't want to wait any later than that or else your helianthemum may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your helianthemum indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Trinity. You should expect an average low temperature of 5°F in the coldest months of winter.

Just be sure to remember that USDA zone info for Trinity may not be accurate from year to year and the actual date of last frost will vary from year to year. Half of the time in Trinity there is a last frost after April 15 so always be ready to protect your helianthemum in the event of one of those late frosts.

USDA Zone Info for Trinity

Here is the info for USDA Zone 7b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	5°F
Highest Expected Low	10°F

This means that on a really cold year, the coldest it will get is 5°F. On most years you should be prepared to experience lows near 10°F.

Plants to Grow in Trinity

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