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 it's the best time to plant alstromeria is to examine the USDA zone info for Rockville.

Planting Calendar for Alstromeria

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

Alstromeria are one of those plants that can tolerate a little bit of cold weather which tells us that you can get them planted earlier than plants that are more sensitive to the cold.

The earliest that you can plant alstromeria in Rockville 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 alstromeria and expect a good harvest is probably September. If you wait any later than that and your alstromeria may not have a chance to fully mature. Starting your alstromeria indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Rockville the average date of last frost happens on April 15. You can expect an average low temperature of 0°F in the coldest months of winter.

Since the USDA zone info for Rockville is just an average the actual date of last frost will vary from year to year. Since half of the time in Rockville last frost occurs after April 15 be ready to cover your alstromeria in the event of a surprise late frost.

USDA Zone Info for Rockville

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 Rockville

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