One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By reviewing the USDA zone info for Silvis you will be able to estimate when it's a good idea to plant lobelia.

Planting Calendar for Lobelia

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

Lobelia do well in cold which tells us that you can plant them much earlier than other frost tender plants.

The earliest that you can plant lobelia in Silvis 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. Starting your lobelia indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Silvis the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of -15°F.

Keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Silvis and it will vary from year to year. Since half of the time in Silvis last frost occurs after April 15 be ready to cover your lobelia if you have a late frost.

USDA Zone Info for Silvis

Here is the info for USDA Zone 5b.

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

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Silvis

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