Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Markham should be reviewed to figure out when it's the best time to plant alternanthera.

Planting Calendar for Alternanthera

Frost tolerance for alternanthera:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

You can not plant alternanthera until after the last frost because they do not do well in cold weather.

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

The last month that you can plant alternanthera and expect a good harvest is probably August. Any later than that and your alternanthera may not have a chance to fully mature. If you are starting your alternanthera indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Markham. It might get as low as -15°F during the coldest months of winter.

Always keep in mind that USDA zone info for Markham is just an average and the actual date of last frost is different every year. Since half of the time in Markham there is a last frost after April 15 be ready to cover your alternanthera if you have one of those late frosts.

USDA Zone Info for Markham

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 Markham

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