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 estimating when it's a good idea to plant lobelia is to refer to the USDA zone info for Hillsboro.

Planting Calendar for Lobelia

Frost tolerance for lobelia:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

You can plant lobelia quite a bit earlier in the year because they do well in cold.

The earliest that you can plant lobelia in Hillsboro 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 lobelia and expect a good harvest is probably September. If you wait any later than that and your lobelia may not have a chance to really do well. You can get started a couple of weeks earlier by starting your lobelia indoors.

Last Frost Date

On average the last frost is on April 15 in Hillsboro. You should expect an average low temperature of -10°F in the coldest months of winter.

It's important to remember that USDA zone info for Hillsboro is just an average and the actual date of last frost can change quite a bit from year to year. Since half of the time in Hillsboro it frosts late in the year after April 15 be ready to protect your lobelia if you have one of those late frosts.

USDA Zone Info for Hillsboro

Here is the info for USDA Zone 6a.

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

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

Plants to Grow in Hillsboro

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