Gardening in zone 3 is tricky. The average last frost date is between May 1st and May 31st, and the average first frost date is between September 1st and September 15th. These are averages, however, and there’s a very good chance that your growing season will turn out to be even shorter. It is because of this, starting seeds indoors in the spring is pretty much essential with zone 3 gardening. Keep reading to learn more about how and when to start seeds in zone 3.
Zone 3 Seed Starting
Starting seeds in zone 3 indoors is sometimes the only way to get a plant to reach maturity in the cold, short growing season of this region. If you look at the back of most seed packets, you’ll see a recommended number of weeks before the average last frost date to start the seeds indoors. These seeds can more or less be grouped into three groups: cold hardy, hot weather, and fast-growing hot weather.
- The cold hardy seeds like kale, broccoli, and brussels sprouts can be started very early, between March 1st and March 15th, or about six weeks prior to transplanting out.
- The second group includes tomatoes, peppers, and eggplants. These seeds should be started between March 15th and April 1st.
- The third group, which includes cucumbers, squash, and melons, should be started just a couple weeks before the last frost date sometime in mid-May.
Seedling Planting Times for Zone 3
Seedling planting times for zone 3 depend upon both frost dates and the type of plant. The reason zone 3 seed starting dates are so early for cold hardy plants is that the seedlings can be transplanted outdoors well before the last frost date. These plants can usually be moved outdoors anytime between April 15th and June 1st. Just make sure to harden them off gradually, or they may not survive the cold nights. Seedlings from the second and third groups should be transplanted after all chance of frost has passed, ideally after June 1st.
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The only child of a horticulturist and an English teacher, Liz Baessler was destined to become a gardening editor. She has been with Gardening Know how since 2015, and a Senior Editor since 2020. She holds a BA in English from Brandeis University and an MA in English from the University of Geneva, Switzerland. After years of gardening in containers and community garden plots, she finally has a backyard of her own, which she is systematically filling with vegetables and flowers.