Use this planting calendar to find the best times of the year to grow fruits, vegetables, herbs, flowers, and other popular plants in Harper, IA, based on the USDA Hardiness Zone 5b.
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Harper, IA Frost Dates & Growing Season
Last Spring Frost Date for Harper, IA
The average last frost date in spring for Harper is April 28th. For gardeners planting sensitive crops like tomatoes, peppers, and basil, it is generally recommended to wait until May 12th before moving plants outdoors. Waiting these extra few weeks significantly reduces the risk of a late freeze damaging young transplants.
First Fall Frost Date for Harper, IA
The average first frost date in fall for Harper is October 9th. This date marks the approximate end of the growing season for tender plants. Gardeners should plan to harvest frost-sensitive vegetables or provide heavy protection (such as row covers) before this date to avoid crop loss.
Growing Season Length in Harper, IA
Based on historical frost data, the estimated growing season length in Harper is approximately 164 days. This duration determines which vegetable varieties have enough time to reach maturity before the winter cold sets in. Short-season varieties are recommended for crops that require a longer warm period.
Please note: These dates are climatological averages. Actual weather conditions vary by year. Always check the local 10-day forecast before planting.
Harper, IA Planting Calendar
This weekly planting calendar displays the ideal windows for starting seeds, transplanting, and harvesting your plants.
Harper, IA Monthly Planting Recommendations
February
In February, recommended activities include starting Leek seeds indoors (from February 17th to March 3rd), starting Celery seeds indoors (from February 17th to March 3rd), and starting Onion seeds indoors (from February 17th to March 3rd).
March
In March, recommended activities include direct sowing Potato (from March 31st to April 14th), direct sowing Flax (from March 31st to April 14th), and starting Cabbage seeds indoors (from March 3rd to March 17th).
April
In April, recommended activities include direct sowing Carrot (from April 7th to April 21st), direct sowing Swiss Chard (from April 14th to April 28th), and direct sowing Lemon Balm (from April 28th to May 12th).
May
In May, recommended activities include direct sowing Sesame (from May 12th to May 26th), direct sowing Cosmos (from May 5th to May 12th), and direct sowing Cucumber (from May 5th to May 19th).